src/gles/render_backend_gles.cpp

/*
 * Copyright (c) 2024 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include "render_backend_gles.h"

#include <algorithm>

#include <base/containers/fixed_string.h>
#include <core/perf/intf_performance_data_manager.h>
#include <render/datastore/render_data_store_render_pods.h> // NodeGraphBackbufferConfiguration...
#include <render/namespace.h>

#if (RENDER_PERF_ENABLED == 1)
#include "perf/gpu_query.h"
#include "perf/gpu_query_manager.h"
#endif
#include "device/gpu_resource_manager.h"
#include "gles/device_gles.h"
#include "gles/gl_functions.h"
#include "gles/gpu_buffer_gles.h"
#include "gles/gpu_image_gles.h"
#include "gles/gpu_program_gles.h"
#include "gles/gpu_query_gles.h"
#include "gles/gpu_sampler_gles.h"
#include "gles/gpu_semaphore_gles.h"
#include "gles/node_context_descriptor_set_manager_gles.h"
#include "gles/node_context_pool_manager_gles.h"
#include "gles/pipeline_state_object_gles.h"
#include "gles/render_frame_sync_gles.h"
#include "gles/swapchain_gles.h"
#include "nodecontext/render_command_list.h"
#include "nodecontext/render_node_graph_node_store.h" // RenderCommandFrameData
#include "util/log.h"
#include "util/render_frame_util.h"

#define IS_BIT(value, bit) ((((value) & (bit)) == (bit)) ? true : false)
#define IS_BIT_GL(value, bit) ((((value) & (bit)) == (bit)) ? (GLboolean)GL_TRUE : (GLboolean)GL_FALSE)

using namespace BASE_NS;

// NOTE: implement missing commands, add state caching and cleanup a bit more.
RENDER_BEGIN_NAMESPACE()
namespace Gles {
// Indices to colorBlendConstants
static constexpr uint32_t RED_INDEX = 0;
static constexpr uint32_t GREEN_INDEX = 1;
static constexpr uint32_t BLUE_INDEX = 2;
static constexpr uint32_t ALPHA_INDEX = 3;
static constexpr uint32_t CUBEMAP_LAYERS = 6;
struct Bind {
    DescriptorType descriptorType { CORE_DESCRIPTOR_TYPE_MAX_ENUM };
    struct BufferType {
        uint32_t bufferId;
        uint32_t offset;
        uint32_t size;
    };
    struct ImageType {
        GpuImageGLES* image;
        uint32_t mode;
        uint32_t mipLevel;
    };
    struct SamplerType {
        uint32_t samplerId;
    };
    struct Resource {
        union {
            Bind::BufferType buffer { 0, 0, 0 };
            Bind::ImageType image;
        };
        SamplerType sampler { 0 };
    };
    vector<Resource> resources;
};
} // namespace Gles
namespace {
constexpr RenderHandleType GetRenderHandleType(const DescriptorType descriptorType)
{
    if (descriptorType == CORE_DESCRIPTOR_TYPE_SAMPLER) {
        return RenderHandleType::GPU_SAMPLER;
    } else if (((descriptorType >= CORE_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER) &&
                   (descriptorType <= CORE_DESCRIPTOR_TYPE_STORAGE_IMAGE)) ||
               (descriptorType == CORE_DESCRIPTOR_TYPE_INPUT_ATTACHMENT)) {
        return RenderHandleType::GPU_IMAGE;
    } else if ((descriptorType >= CORE_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER) &&
               (descriptorType <= CORE_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC)) {
        return RenderHandleType::GPU_BUFFER;
    }
    return RenderHandleType::UNDEFINED;
}

GLenum getCubeMapTarget(GLenum type, uint32_t layer)
{
    if (type == GL_TEXTURE_CUBE_MAP) {
        constexpr GLenum layerId[] = { GL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X,
            GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, GL_TEXTURE_CUBE_MAP_POSITIVE_Z,
            GL_TEXTURE_CUBE_MAP_NEGATIVE_Z, 0 };
        PLUGIN_ASSERT_MSG(layer < Gles::CUBEMAP_LAYERS, "Invalid cubemap index %u", layer);
        return layerId[layer];
    }
    PLUGIN_ASSERT_MSG(false, "Unhandled type in getTarget! %x", type);
    return GL_NONE;
}

GLenum getTarget(GLenum type, uint32_t layer, uint32_t sampleCount)
{
    if (type == GL_TEXTURE_2D) {
        if (sampleCount > 1) {
            return GL_TEXTURE_2D_MULTISAMPLE;
        }
        return GL_TEXTURE_2D;
    }
    if (type == GL_TEXTURE_CUBE_MAP) {
        PLUGIN_ASSERT_MSG(sampleCount == 1, "Cubemap texture can't have MSAA");
        return getCubeMapTarget(type, layer);
    }
    PLUGIN_ASSERT_MSG(false, "Unhandled type in getTarget! %x", type);
    return GL_NONE;
}
struct BlitArgs {
    uint32_t mipLevel {};
    Size3D rect0 {};
    Size3D rect1 {};
    uint32_t height {};
};

void DoBlit(const Filter filter, const BlitArgs& src, const BlitArgs& dst)
{
    // Handle top-left / bottom-left origin conversion
    GLint sy = static_cast<GLint>(src.rect0.height);
    const GLint sh = static_cast<const GLint>(src.rect1.height);
    const GLint sfh = static_cast<GLint>(src.height >> src.mipLevel);
    sy = sfh - (sy + sh);
    GLint dy = static_cast<GLint>(dst.rect0.height);
    const GLint dh = static_cast<const GLint>(dst.rect1.height);
    const GLint dfh = static_cast<GLint>(dst.height >> dst.mipLevel);
    dy = dfh - (dy + dh);
    GLenum glfilter = GL_NEAREST;
    if (filter == CORE_FILTER_NEAREST) {
        glfilter = GL_NEAREST;
    } else if (filter == CORE_FILTER_LINEAR) {
        glfilter = GL_LINEAR;
    } else {
        PLUGIN_ASSERT_MSG(false, "RenderCommandBlitImage Invalid filter mode");
    }
    glBlitFramebuffer(static_cast<GLint>(src.rect0.width), sy, static_cast<GLint>(src.rect1.width), sfh,
        static_cast<GLint>(dst.rect0.width), dy, static_cast<GLint>(dst.rect1.width), dfh, GL_COLOR_BUFFER_BIT,
        glfilter);
}

GLenum GetPrimFromTopology(PrimitiveTopology op)
{
    switch (op) {
        case CORE_PRIMITIVE_TOPOLOGY_POINT_LIST:
            return GL_POINTS;
        case CORE_PRIMITIVE_TOPOLOGY_LINE_LIST:
            return GL_LINES;
        case CORE_PRIMITIVE_TOPOLOGY_LINE_STRIP:
            return GL_LINE_STRIP;
        case CORE_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST:
            return GL_TRIANGLES;
        case CORE_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP:
            return GL_TRIANGLE_STRIP;
        case CORE_PRIMITIVE_TOPOLOGY_TRIANGLE_FAN:
            return GL_TRIANGLE_FAN;
#if defined(GL_ES_VERSION_3_2) || defined(GL_VERSION_3_2)
            // The following are valid after gles 3.2
        case CORE_PRIMITIVE_TOPOLOGY_LINE_LIST_WITH_ADJACENCY:
            return GL_LINES_ADJACENCY;
        case CORE_PRIMITIVE_TOPOLOGY_LINE_STRIP_WITH_ADJACENCY:
            return GL_LINE_STRIP_ADJACENCY;
        case CORE_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST_WITH_ADJACENCY:
            return GL_TRIANGLES_ADJACENCY;
        case CORE_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP_WITH_ADJACENCY:
            return GL_TRIANGLE_STRIP_ADJACENCY;
        case CORE_PRIMITIVE_TOPOLOGY_PATCH_LIST:
            return GL_PATCHES;
#endif
        default:
            PLUGIN_ASSERT_MSG(false, "Unsupported primitive topology");
            break;
    }
    return GL_POINTS;
}

GLenum GetBlendOp(BlendOp func)
{
    switch (func) {
        case CORE_BLEND_OP_ADD:
            return GL_FUNC_ADD;
        case CORE_BLEND_OP_SUBTRACT:
            return GL_FUNC_SUBTRACT;
        case CORE_BLEND_OP_REVERSE_SUBTRACT:
            return GL_FUNC_REVERSE_SUBTRACT;
        case CORE_BLEND_OP_MIN:
            return GL_MIN;
        case CORE_BLEND_OP_MAX:
            return GL_MAX;
        default:
            break;
    }
    return GL_FUNC_ADD;
}

GLenum GetBlendFactor(BlendFactor factor)
{
    switch (factor) {
        case CORE_BLEND_FACTOR_ZERO:
            return GL_ZERO;
        case CORE_BLEND_FACTOR_ONE:
            return GL_ONE;
        case CORE_BLEND_FACTOR_SRC_COLOR:
            return GL_SRC_COLOR;
        case CORE_BLEND_FACTOR_ONE_MINUS_SRC_COLOR:
            return GL_ONE_MINUS_SRC_COLOR;
        case CORE_BLEND_FACTOR_DST_COLOR:
            return GL_DST_COLOR;
        case CORE_BLEND_FACTOR_ONE_MINUS_DST_COLOR:
            return GL_ONE_MINUS_DST_COLOR;
        case CORE_BLEND_FACTOR_SRC_ALPHA:
            return GL_SRC_ALPHA;
        case CORE_BLEND_FACTOR_ONE_MINUS_SRC_ALPHA:
            return GL_ONE_MINUS_SRC_ALPHA;
        case CORE_BLEND_FACTOR_DST_ALPHA:
            return GL_DST_ALPHA;
        case CORE_BLEND_FACTOR_ONE_MINUS_DST_ALPHA:
            return GL_ONE_MINUS_DST_ALPHA;
        case CORE_BLEND_FACTOR_CONSTANT_COLOR:
            return GL_CONSTANT_COLOR;
        case CORE_BLEND_FACTOR_ONE_MINUS_CONSTANT_COLOR:
            return GL_ONE_MINUS_CONSTANT_COLOR;
        case CORE_BLEND_FACTOR_CONSTANT_ALPHA:
            return GL_CONSTANT_ALPHA;
        case CORE_BLEND_FACTOR_ONE_MINUS_CONSTANT_ALPHA:
            return GL_ONE_MINUS_CONSTANT_ALPHA;
        case CORE_BLEND_FACTOR_SRC_ALPHA_SATURATE:
            return GL_SRC_ALPHA_SATURATE;
            // NOTE: check the GLES3.2...
            /* following requires EXT_blend_func_extended (dual source blending) */
        case CORE_BLEND_FACTOR_SRC1_COLOR:
        case CORE_BLEND_FACTOR_ONE_MINUS_SRC1_COLOR:
        case CORE_BLEND_FACTOR_SRC1_ALPHA:
        case CORE_BLEND_FACTOR_ONE_MINUS_SRC1_ALPHA:
        default:
            break;
    }
    return GL_ONE;
}

GLenum GetCompareOp(CompareOp aOp)
{
    switch (aOp) {
        case CORE_COMPARE_OP_NEVER:
            return GL_NEVER;
        case CORE_COMPARE_OP_LESS:
            return GL_LESS;
        case CORE_COMPARE_OP_EQUAL:
            return GL_EQUAL;
        case CORE_COMPARE_OP_LESS_OR_EQUAL:
            return GL_LEQUAL;
        case CORE_COMPARE_OP_GREATER:
            return GL_GREATER;
        case CORE_COMPARE_OP_NOT_EQUAL:
            return GL_NOTEQUAL;
        case CORE_COMPARE_OP_GREATER_OR_EQUAL:
            return GL_GEQUAL;
        case CORE_COMPARE_OP_ALWAYS:
            return GL_ALWAYS;
        default:
            break;
    }
    return GL_ALWAYS;
}

GLenum GetStencilOp(StencilOp aOp)
{
    switch (aOp) {
        case CORE_STENCIL_OP_KEEP:
            return GL_KEEP;
        case CORE_STENCIL_OP_ZERO:
            return GL_ZERO;
        case CORE_STENCIL_OP_REPLACE:
            return GL_REPLACE;
        case CORE_STENCIL_OP_INCREMENT_AND_CLAMP:
            return GL_INCR;
        case CORE_STENCIL_OP_DECREMENT_AND_CLAMP:
            return GL_DECR;
        case CORE_STENCIL_OP_INVERT:
            return GL_INVERT;
        case CORE_STENCIL_OP_INCREMENT_AND_WRAP:
            return GL_INCR_WRAP;
        case CORE_STENCIL_OP_DECREMENT_AND_WRAP:
            return GL_DECR_WRAP;
        default:
            break;
    }
    return GL_KEEP;
}

void SetState(GLenum type, bool enabled)
{
    if (enabled) {
        glEnable(type);
    } else {
        glDisable(type);
    }
}

void SetCullMode(const GraphicsState::RasterizationState& rs)
{
    SetState(GL_CULL_FACE, (rs.cullModeFlags != CORE_CULL_MODE_NONE));

    switch (rs.cullModeFlags) {
        case CORE_CULL_MODE_FRONT_BIT:
            glCullFace(GL_FRONT);
            break;
        case CORE_CULL_MODE_BACK_BIT:
            glCullFace(GL_BACK);
            break;
        case CORE_CULL_MODE_FRONT_AND_BACK:
            glCullFace(GL_FRONT_AND_BACK);
            break;
        case CORE_CULL_MODE_NONE:
        default:
            break;
    }
}

void SetFrontFace(const GraphicsState::RasterizationState& rs)
{
    switch (rs.frontFace) {
        case CORE_FRONT_FACE_COUNTER_CLOCKWISE:
            glFrontFace(GL_CCW);
            break;
        case CORE_FRONT_FACE_CLOCKWISE:
            glFrontFace(GL_CW);
            break;
        default:
            break;
    }
}

#if RENDER_HAS_GL_BACKEND
void SetPolygonMode(const GraphicsState::RasterizationState& rs)
{
    GLenum mode;
    switch (rs.polygonMode) {
        default:
        case CORE_POLYGON_MODE_FILL:
            mode = GL_FILL;
            break;
        case CORE_POLYGON_MODE_LINE:
            mode = GL_LINE;
            break;
        case CORE_POLYGON_MODE_POINT:
            mode = GL_POINT;
            break;
    }
    glPolygonMode(GL_FRONT_AND_BACK, mode);
}
#endif

void Invalidate(GLenum framebuffer, int32_t count, const GLenum invalidate[], const RenderPassDesc& rpd,
    const LowlevelFramebufferGL& frameBuffer)
{
    if (count > 0) {
        if ((frameBuffer.width == rpd.renderArea.extentWidth) && (frameBuffer.height == rpd.renderArea.extentHeight)) {
            // Invalidate the whole buffer.  (attachment sizes match render area)
            glInvalidateFramebuffer(framebuffer, static_cast<GLsizei>(count), invalidate);
        } else {
            // invalidate only a part of the render target..
            // NOTE: verify that this works, we might need to flip the Y axis the same way as scissors etc.
            const GLint X = static_cast<const GLint>(rpd.renderArea.offsetX);
            const GLint Y = static_cast<const GLint>(rpd.renderArea.offsetY);
            const GLsizei W = static_cast<const GLsizei>(rpd.renderArea.extentWidth);
            const GLsizei H = static_cast<const GLsizei>(rpd.renderArea.extentHeight);
            glInvalidateSubFramebuffer(framebuffer, static_cast<GLsizei>(count), invalidate, X, Y, W, H);
        }
    }
}

struct BlitData {
    const GpuImagePlatformDataGL& iPlat;
    const GpuImageDesc& imageDesc;
    const BufferImageCopy& bufferImageCopy;
    uintptr_t data { 0 };
    uint64_t size { 0 };
    uint64_t sizeOfData { 0 };
    bool compressed { false };
};

void BlitArray(DeviceGLES& device_, const BlitData& bd)
{
    const auto& iPlat = bd.iPlat;
    const auto& bufferImageCopy = bd.bufferImageCopy;
    const auto& imageSubresource = bufferImageCopy.imageSubresource;
    const auto& imageDesc = bd.imageDesc;
    const uint32_t mip = imageSubresource.mipLevel;
    const Math::UVec3 imageSize { imageDesc.width >> mip, imageDesc.height >> mip, imageDesc.depth };
    // NOTE: image offset depth is ignored
    const Math::UVec2 offset { bufferImageCopy.imageOffset.width, bufferImageCopy.imageOffset.height };
    const Math::UVec3 extent3D { Math::min(imageSize.x - offset.x, bufferImageCopy.imageExtent.width),
        Math::min(imageSize.y - offset.y, bufferImageCopy.imageExtent.height),
        Math::min(imageSize.z, bufferImageCopy.imageExtent.depth) };
    const bool valid = (offset.x < imageSize.x) && (offset.y < imageSize.y);
    if (valid) {
        uintptr_t data = bd.data;
        const uint32_t layerCount = imageSubresource.baseArrayLayer + imageSubresource.layerCount;
        for (uint32_t layer = imageSubresource.baseArrayLayer; layer < layerCount; layer++) {
            const Math::UVec3 offset3D { offset.x, offset.y, layer };
            if (bd.compressed) {
                device_.CompressedTexSubImage3D(iPlat.image, iPlat.type, imageSubresource.mipLevel, offset3D, extent3D,
                    iPlat.internalFormat, static_cast<uint32_t>(bd.sizeOfData), reinterpret_cast<const void*>(data));
            } else {
                device_.TexSubImage3D(iPlat.image, iPlat.type, imageSubresource.mipLevel, offset3D, extent3D,
                    iPlat.format, iPlat.dataType, reinterpret_cast<const void*>(data));
            }
            data += static_cast<ptrdiff_t>(bd.sizeOfData);
        }
    }
}

void Blit2D(DeviceGLES& device_, const BlitData& bd)
{
    const auto& iPlat = bd.iPlat;
    const auto& bufferImageCopy = bd.bufferImageCopy;
    const auto& imageSubresource = bufferImageCopy.imageSubresource;
    const auto& imageDesc = bd.imageDesc;
    const uint32_t mip = imageSubresource.mipLevel;
    const Math::UVec2 imageSize { imageDesc.width >> mip, imageDesc.height >> mip };
    const Math::UVec2 offset { bufferImageCopy.imageOffset.width, bufferImageCopy.imageOffset.height };
    const Math::UVec2 extent { Math::min(imageSize.x - offset.x, bufferImageCopy.imageExtent.width),
        Math::min(imageSize.y - offset.y, bufferImageCopy.imageExtent.height) };
    PLUGIN_ASSERT_MSG(imageSubresource.baseArrayLayer == 0 && imageSubresource.layerCount == 1,
        "RenderCommandCopyBufferImage Texture2D with baseArrayLayer!=0 && layerCount!= 1");
    const bool valid = (offset.x < imageSize.x) && (offset.y < imageSize.y);
    const uintptr_t data = bd.data;
    if (valid && bd.compressed) {
        device_.CompressedTexSubImage2D(iPlat.image, iPlat.type, imageSubresource.mipLevel, offset, extent,
            iPlat.internalFormat, static_cast<uint32_t>(bd.sizeOfData), reinterpret_cast<const void*>(data));
    } else if (valid) {
        device_.TexSubImage2D(iPlat.image, iPlat.type, imageSubresource.mipLevel, offset, extent, iPlat.format,
            iPlat.dataType, reinterpret_cast<const void*>(data));
    }
}

void Blit3D(DeviceGLES& device_, const BlitData& bd)
{
    const auto& iPlat = bd.iPlat;
    const auto& bufferImageCopy = bd.bufferImageCopy;
    const auto& imageSubresource = bufferImageCopy.imageSubresource;
    const auto& imageDesc = bd.imageDesc;
    const uint32_t mip = imageSubresource.mipLevel;
    const Math::UVec3 imageSize { imageDesc.width >> mip, imageDesc.height >> mip, imageDesc.depth >> mip };
    const Math::UVec3 offset { bufferImageCopy.imageOffset.width, bufferImageCopy.imageOffset.height,
        bufferImageCopy.imageOffset.depth };
    Math::UVec3 extent3D { Math::min(imageSize.x - offset.x, bufferImageCopy.imageExtent.width),
        Math::min(imageSize.y - offset.y, bufferImageCopy.imageExtent.height), Math::min(imageSize.z - offset.z, 1U) };
    const bool valid = (offset.x < imageSize.x) && (offset.y < imageSize.y);
    if (valid) {
        uintptr_t data = bd.data;
        for (uint32_t slice = 0U; slice < imageSize.z; ++slice) {
            const Math::UVec3 offset3D { offset.x, offset.y, slice };
            if (bd.compressed) {
                device_.CompressedTexSubImage3D(iPlat.image, iPlat.type, imageSubresource.mipLevel, offset3D, extent3D,
                    iPlat.internalFormat, static_cast<uint32_t>(bd.sizeOfData), reinterpret_cast<const void*>(data));
            } else {
                device_.TexSubImage3D(iPlat.image, iPlat.type, imageSubresource.mipLevel, offset3D, extent3D,
                    iPlat.format, iPlat.dataType, reinterpret_cast<const void*>(data));
            }
            // offsets one slice
            data += static_cast<ptrdiff_t>(bd.sizeOfData);
        }
    }
}

void BlitCube(DeviceGLES& device_, const BlitData& bd)
{
    const auto& iPlat = bd.iPlat;
    const auto& bufferImageCopy = bd.bufferImageCopy;
    const auto& imageSubresource = bufferImageCopy.imageSubresource;
    const Math::UVec2 offset { bufferImageCopy.imageOffset.width, bufferImageCopy.imageOffset.height };
    const Math::UVec2 extent { bufferImageCopy.imageExtent.width, bufferImageCopy.imageExtent.height };
    constexpr GLenum faceId[] = { GL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X,
        GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, GL_TEXTURE_CUBE_MAP_POSITIVE_Z,
        GL_TEXTURE_CUBE_MAP_NEGATIVE_Z, 0 };
    PLUGIN_UNUSED(Gles::CUBEMAP_LAYERS);
    PLUGIN_ASSERT_MSG(imageSubresource.baseArrayLayer == 0 && imageSubresource.layerCount == Gles::CUBEMAP_LAYERS,
        "RenderCommandCopyBufferImage Cubemap with baseArrayLayer!=0 && layerCount!= 6");
    uintptr_t data = bd.data;
    const uint32_t lastLayer = imageSubresource.baseArrayLayer + imageSubresource.layerCount;
    for (uint32_t i = imageSubresource.baseArrayLayer; i < lastLayer; i++) {
        const GLenum face = faceId[i]; // convert layer index to cube map face id.
        if (face == 0) {
            // reached the end of cubemap faces (see faceId)
            // so must stop copying.
            break;
        }
        if (bd.compressed) {
            device_.CompressedTexSubImage2D(iPlat.image, face, imageSubresource.mipLevel, offset, extent,
                iPlat.internalFormat, static_cast<uint32_t>(bd.sizeOfData), reinterpret_cast<const void*>(data));
        } else {
            device_.TexSubImage2D(iPlat.image, face, imageSubresource.mipLevel, offset, extent, iPlat.format,
                iPlat.dataType, reinterpret_cast<const void*>(data));
        }
        data += static_cast<ptrdiff_t>(bd.sizeOfData);
    }
}
template<bool usePixelUnpackBuffer>

BlitData SetupBlit(DeviceGLES& device_, const BufferImageCopy& bufferImageCopy, GpuBufferGLES& srcGpuBuffer,
    const GpuImageGLES& dstGpuImage)
{
    const auto& iPlat = dstGpuImage.GetPlatformData();
    const auto& imageOffset = bufferImageCopy.imageOffset;
    PLUGIN_UNUSED(imageOffset);
    const auto& imageExtent = bufferImageCopy.imageExtent;
    // size is calculated for single layer / slice
    const uint64_t size = static_cast<uint64_t>(iPlat.bytesperpixel) *
                          static_cast<uint64_t>(bufferImageCopy.bufferImageHeight) *
                          static_cast<uint64_t>(bufferImageCopy.bufferRowLength);
    uintptr_t data = bufferImageCopy.bufferOffset;
    if constexpr (usePixelUnpackBuffer) {
        const auto& plat = srcGpuBuffer.GetPlatformData();
        device_.BindBuffer(GL_PIXEL_UNPACK_BUFFER, plat.buffer);
    } else {
        // Use the mapped pointer for glTexSubImage2D, this is a workaround on GL_INVALID_OPERATION on PVR GLES
        // simulator and crash with ETC2 textures on NVIDIA..
        data += reinterpret_cast<uintptr_t>(srcGpuBuffer.Map());
    }
    uint64_t sizeOfData = size;
    const auto& compinfo = iPlat.compression;
    if (compinfo.compressed) {
        // how many blocks in width
        const int64_t blockW = (imageExtent.width + (compinfo.blockW - 1)) / compinfo.blockW;
        // how many blocks in height
        const int64_t blockH = (imageExtent.height + (compinfo.blockH - 1)) / compinfo.blockH;
        // size in bytes..
        sizeOfData = static_cast<uint64_t>(((blockW * blockH) * compinfo.bytesperblock));

        // Warn for partial copies. we do not handle those at the moment.
        if (bufferImageCopy.bufferRowLength != 0) {
            if (bufferImageCopy.bufferRowLength != blockW * compinfo.blockW) {
                PLUGIN_LOG_W("Partial copies of compressed texture data is not currently supported. "
                             "Stride must match image width (with block align). "
                             "bufferImageCopy.bufferRowLength(%d) "
                             "imageExtent.width(%d) ",
                    bufferImageCopy.bufferRowLength, imageExtent.width);
            }
        }
        glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
        glPixelStorei(GL_UNPACK_IMAGE_HEIGHT, 0);
    } else {
        glPixelStorei(GL_UNPACK_ROW_LENGTH, static_cast<GLint>(bufferImageCopy.bufferRowLength));
        glPixelStorei(GL_UNPACK_IMAGE_HEIGHT, static_cast<GLint>(bufferImageCopy.bufferImageHeight));
    }
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1); // Make sure the align is tight.
    return { iPlat, dstGpuImage.GetDesc(), bufferImageCopy, data, size, sizeOfData, compinfo.compressed };
}

template<bool usePixelUnpackBuffer>
void FinishBlit(DeviceGLES& device_, const GpuBufferGLES& srcGpuBuffer)
{
    if constexpr (usePixelUnpackBuffer) {
        device_.BindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
    } else {
        srcGpuBuffer.Unmap();
    }
}

template<typename T, size_t N>
constexpr size_t Compare(const T (&a)[N], const T (&b)[N])
{
    for (size_t i = 0; i < N; i++) {
        if (a[i] != b[i])
            return false;
    }
    return true;
}

template<typename T, size_t N>

constexpr size_t Set(T (&a)[N], const T (&b)[N])
{
    for (size_t i = 0; i < N; i++) {
        a[i] = b[i];
    }
    return true;
}

bool CompareBlendFactors(
    const GraphicsState::ColorBlendState::Attachment& a, const GraphicsState::ColorBlendState::Attachment& b)
{
    return (a.srcColorBlendFactor == b.srcColorBlendFactor) && (a.srcAlphaBlendFactor == b.srcAlphaBlendFactor) &&
           (a.dstColorBlendFactor == b.dstColorBlendFactor) && (a.dstAlphaBlendFactor == b.dstAlphaBlendFactor);
}

void SetBlendFactors(GraphicsState::ColorBlendState::Attachment& a, const GraphicsState::ColorBlendState::Attachment& b)
{
    a.srcColorBlendFactor = b.srcColorBlendFactor;
    a.srcAlphaBlendFactor = b.srcAlphaBlendFactor;
    a.dstColorBlendFactor = b.dstColorBlendFactor;
    a.dstAlphaBlendFactor = b.dstAlphaBlendFactor;
}

bool CompareBlendOps(
    const GraphicsState::ColorBlendState::Attachment& a, const GraphicsState::ColorBlendState::Attachment& b)
{
    return (a.colorBlendOp == b.colorBlendOp) && (a.alphaBlendOp == b.alphaBlendOp);
}

void SetBlendOps(GraphicsState::ColorBlendState::Attachment& a, const GraphicsState::ColorBlendState::Attachment& b)
{
    a.colorBlendOp = b.colorBlendOp;
    a.alphaBlendOp = b.alphaBlendOp;
}

bool CompareStencilOp(const GraphicsState::StencilOpState& a, const GraphicsState::StencilOpState& b)
{
    return (a.failOp == b.failOp) && (a.depthFailOp == b.depthFailOp) && (a.passOp == b.passOp);
}

void SetStencilOp(GraphicsState::StencilOpState& a, const GraphicsState::StencilOpState& b)
{
    a.failOp = b.failOp;
    a.depthFailOp = b.depthFailOp;
    a.passOp = b.passOp;
}

void SetStencilCompareOp(GraphicsState::StencilOpState& a, const GraphicsState::StencilOpState& b)
{
    a.compareOp = b.compareOp;
    a.compareMask = b.compareMask;
    a.reference = b.reference;
}

#if RENDER_VALIDATION_ENABLED
void ValidateCopyImage(const Offset3D& offset, const Size3D& extent, uint32_t mipLevel, const GpuImageDesc& imageDesc)
{
    if (mipLevel >= imageDesc.mipCount) {
        PLUGIN_LOG_W("RENDER_VALIDATION: CopyImage mipLevel must be less than image mipCount.");
    }
    if ((offset.x < 0) || (offset.y < 0) || (offset.z < 0)) {
        PLUGIN_LOG_W("RENDER_VALIDATION: CopyImage offset must not be negative.");
    }
    if (((offset.x + extent.width) > imageDesc.width) || ((offset.y + extent.height) > imageDesc.height) ||
        ((offset.z + extent.depth) > imageDesc.depth)) {
        PLUGIN_LOG_W("RENDER_VALIDATION: CopyImage offset + extent does not fit in image.");
    }
}

void ValidateCopyImage(const ImageCopy& imageCopy, const GpuImageDesc& srcImageDesc, const GpuImageDesc& dstImageDesc)
{
    ValidateCopyImage(imageCopy.srcOffset, imageCopy.extent, imageCopy.srcSubresource.mipLevel, srcImageDesc);
    ValidateCopyImage(imageCopy.dstOffset, imageCopy.extent, imageCopy.dstSubresource.mipLevel, dstImageDesc);
}
#endif

constexpr void ClampOffset(int32_t& srcOffset, int32_t& dstOffset, uint32_t& size)
{
    if (srcOffset < 0) {
        size += srcOffset;
        dstOffset -= srcOffset;
        srcOffset = 0;
    }
}

constexpr void ClampOffset(Offset3D& srcOffset, Offset3D& dstOffset, Size3D& size)
{
    ClampOffset(srcOffset.x, dstOffset.x, size.width);
    ClampOffset(srcOffset.y, dstOffset.y, size.height);
    ClampOffset(srcOffset.z, dstOffset.z, size.depth);
}

constexpr void ClampSize(int32_t offset, uint32_t maxSize, uint32_t& size)
{
    if (size > (maxSize - offset)) {
        size = maxSize - offset;
    }
}

constexpr void ClampSize(const Offset3D& offset, const GpuImageDesc& desc, Size3D& size)
{
    ClampSize(offset.x, desc.width, size.width);
    ClampSize(offset.y, desc.height, size.height);
    ClampSize(offset.z, desc.depth, size.depth);
}
} // namespace

RenderBackendGLES::RenderBackendGLES(Device& device, GpuResourceManager& gpuResourceManager)
    : RenderBackend(), device_(static_cast<DeviceGLES&>(device)), gpuResourceMgr_(gpuResourceManager)
{
#if (RENDER_PERF_ENABLED == 1)
    validGpuQueries_ = false;
#if (RENDER_GPU_TIMESTAMP_QUERIES_ENABLED == 1)
    gpuQueryMgr_ = make_unique<GpuQueryManager>();
#if RENDER_HAS_GL_BACKEND
    if (device_.GetBackendType() == DeviceBackendType::OPENGL) {
        validGpuQueries_ = true;
    }
#endif
#if RENDER_HAS_GLES_BACKEND
    if (device_.GetBackendType() == DeviceBackendType::OPENGLES) {
        // Check if GL_EXT_disjoint_timer_query is available.
        validGpuQueries_ = device_.HasExtension("GL_EXT_disjoint_timer_query");
    }
#endif
#endif // RENDER_GPU_TIMESTAMP_QUERIES_ENABLED
#endif // RENDER_PERF_ENABLED
#if RENDER_HAS_GLES_BACKEND
    if (device_.GetBackendType() == DeviceBackendType::OPENGLES) {
        multisampledRenderToTexture_ = device_.HasExtension("GL_EXT_multisampled_render_to_texture2");
    }
#endif
    PLUGIN_ASSERT(device_.IsActive());
    PrimeCache(GraphicsState {}); // Initializes cache.
    glGenFramebuffers(1, &blitImageSourceFbo_);
    glGenFramebuffers(1, &blitImageDestinationFbo_);
#if (RENDER_DEBUG_GPU_RESOURCE_IDS == 1)
    PLUGIN_LOG_D("fbo id >: %u", blitImageSourceFbo_);
    PLUGIN_LOG_D("fbo id >: %u", blitImageDestinationFbo_);
#endif
#if !RENDER_HAS_GLES_BACKEND
    glEnable(GL_PROGRAM_POINT_SIZE);
#endif
}

RenderBackendGLES::~RenderBackendGLES()
{
    PLUGIN_ASSERT(device_.IsActive());
    device_.DeleteFrameBuffer(blitImageSourceFbo_);
    device_.DeleteFrameBuffer(blitImageDestinationFbo_);
}

void RenderBackendGLES::Present(const RenderBackendBackBufferConfiguration& backBufferConfig)
{
    if (!backBufferConfig.swapchainData.empty()) {
        if (device_.HasSwapchain()) {
#if (RENDER_PERF_ENABLED == 1)
            commonCpuTimers_.present.Begin();
#endif
            for (const auto& swapchainData : backBufferConfig.swapchainData) {
#if (RENDER_DEV_ENABLED == 1)
                if (swapchainData.config.gpuSemaphoreHandle) {
                    // NOTE: not implemented
                    PLUGIN_LOG_E("NodeGraphBackBufferConfiguration semaphore not signaled");
                }
#endif
                const auto* swp = static_cast<const SwapchainGLES*>(device_.GetSwapchain(swapchainData.handle));
                if (swp) {
#if RENDER_GL_FLIP_Y_SWAPCHAIN
                    // Blit and flip our swapchain frame to backbuffer..
                    const auto& sdesc = swp->GetDesc();
                    if (scissorEnabled_) {
                        glDisable(GL_SCISSOR_TEST);
                        scissorEnabled_ = false;
                    }
                    const auto& platSwapchain = swp->GetPlatformData();
                    device_.BindReadFrameBuffer(platSwapchain.fbos[presentationInfo_.swapchainImageIndex]);
                    device_.BindWriteFrameBuffer(0); // FBO 0  is the surface bound to current context..
                    glBlitFramebuffer(0, 0, (GLint)sdesc.width, (GLint)sdesc.height, 0, (GLint)sdesc.height,
                        (GLint)sdesc.width, 0, GL_COLOR_BUFFER_BIT, GL_NEAREST);
                    device_.BindReadFrameBuffer(0);
#endif
                    device_.SwapBuffers(*swp);
                }
            }
#if (RENDER_PERF_ENABLED == 1)
            commonCpuTimers_.present.End();
#endif
        }
    }
}

void RenderBackendGLES::ResetState()
{
    boundProgram_ = {};
    boundIndexBuffer_ = {};
    vertexAttribBinds_ = 0;
    renderingToDefaultFbo_ = false;
    boundComputePipeline_ = nullptr;
    boundGraphicsPipeline_ = nullptr;
    currentPsoHandle_ = {};
    renderArea_ = {};
    activeRenderPass_ = {};
    currentSubPass_ = 0;
    currentFrameBuffer_ = nullptr;
    scissorBoxUpdated_ = viewportDepthRangeUpdated_ = viewportUpdated_ = true;
    inRenderpass_ = 0;
}

void RenderBackendGLES::ResetBindings()
{
    for (auto& b : boundObjects_) {
        b.dirty = true;
    }
    boundComputePipeline_ = nullptr;
    boundGraphicsPipeline_ = nullptr;
    currentPsoHandle_ = {};
}

void RenderBackendGLES::Render(
    RenderCommandFrameData& renderCommandFrameData, const RenderBackendBackBufferConfiguration& backBufferConfig)
{
    // NOTE: all command lists are validated before entering here
    PLUGIN_ASSERT(device_.IsActive());
#if (RENDER_PERF_ENABLED == 1)
    commonCpuTimers_.full.Begin();
    commonCpuTimers_.acquire.Begin();
#endif
    presentationInfo_ = {};

    if (device_.HasSwapchain() && (!backBufferConfig.swapchainData.empty())) {
        for (size_t swapIdx = 0; swapIdx < backBufferConfig.swapchainData.size(); ++swapIdx) {
            const auto& swapData = backBufferConfig.swapchainData[swapIdx];
            if (const SwapchainGLES* swp = static_cast<const SwapchainGLES*>(device_.GetSwapchain(swapData.handle))) {
                presentationInfo_.swapchainImageIndex = swp->GetNextImage();
                const Device::SwapchainData swapchainData = device_.GetSwapchainData(swapData.handle);
                if (presentationInfo_.swapchainImageIndex < swapchainData.imageViewCount) {
                    // remap image to backbuffer
                    const RenderHandle currentSwapchainHandle =
                        swapchainData.imageViews[presentationInfo_.swapchainImageIndex];
                    // special swapchain remapping
                    gpuResourceMgr_.RenderBackendImmediateRemapGpuImageHandle(swapData.handle, currentSwapchainHandle);
                }
            }
        }
    }
#if (RENDER_PERF_ENABLED == 1)
    commonCpuTimers_.acquire.End();

    StartFrameTimers(renderCommandFrameData);
    commonCpuTimers_.execute.Begin();
#endif
    // Reset bindings.
    ResetState();
    for (const auto& ref : renderCommandFrameData.renderCommandContexts) {
        // Reset bindings between command lists..
        ResetBindings();
        RenderSingleCommandList(ref);
    }
#if (RENDER_PERF_ENABLED == 1)
    commonCpuTimers_.execute.End();
#endif
    RenderProcessEndCommandLists(renderCommandFrameData, backBufferConfig);
#if (RENDER_PERF_ENABLED == 1)
    commonCpuTimers_.full.End();
    EndFrameTimers();
#endif
}

void RenderBackendGLES::RenderProcessEndCommandLists(
    RenderCommandFrameData& renderCommandFrameData, const RenderBackendBackBufferConfiguration& backBufferConfig)
{
    if (auto* frameSync = static_cast<RenderFrameSyncGLES*>(renderCommandFrameData.renderFrameSync); frameSync) {
        frameSync->GetFrameFence();
    }
    // signal external GPU fences
    if (renderCommandFrameData.renderFrameUtil && renderCommandFrameData.renderFrameUtil->HasGpuSignals()) {
        auto externalSignals = renderCommandFrameData.renderFrameUtil->GetFrameGpuSignalData();
        const auto externalSemaphores = renderCommandFrameData.renderFrameUtil->GetGpuSemaphores();
        PLUGIN_ASSERT(externalSignals.size() == externalSemaphores.size());
        if (externalSignals.size() == externalSemaphores.size()) {
            for (size_t sigIdx = 0; sigIdx < externalSignals.size(); ++sigIdx) {
                // needs to be false
                if (!externalSignals[sigIdx].signaled && (externalSemaphores[sigIdx])) {
                    if (const GpuSemaphoreGles* gs = (const GpuSemaphoreGles*)externalSemaphores[sigIdx].get(); gs) {
                        auto& plat = const_cast<GpuSemaphorePlatformDataGles&>(gs->GetPlatformData());
                        // NOTE: currently could create only one GPU sync
                        GLsync sync = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
                        plat.sync = static_cast<uint64_t>(reinterpret_cast<uintptr_t>(sync));
                        externalSignals[sigIdx].gpuSignalResourceHandle = plat.sync;
                        externalSignals[sigIdx].signaled = true;

                        // NOTE: client is expected to add code for the wait with glClientWaitSync(sync, X, 0)
                    }
                }
            }
        }
    }
}

void RenderBackendGLES::RenderCommandUndefined(const RenderCommandWithType& renderCommand)
{
    PLUGIN_ASSERT_MSG(false, "non-valid render command");
}

void RenderBackendGLES::RenderSingleCommandList(const RenderCommandContext& renderCommandCtx)
{
    // these are validated in render graph
    managers_ = { renderCommandCtx.nodeContextPsoMgr, renderCommandCtx.nodeContextPoolMgr,
        renderCommandCtx.nodeContextDescriptorSetMgr, renderCommandCtx.renderBarrierList };

    managers_.poolMgr->BeginBackendFrame();
    managers_.psoMgr->BeginBackendFrame();
#if (RENDER_PERF_ENABLED == 1) || (RENDER_DEBUG_MARKERS_ENABLED == 1)
    const auto& debugName = renderCommandCtx.debugName;
#endif
#if (RENDER_PERF_ENABLED == 1)
    perfCounters_ = {};
    PLUGIN_ASSERT(timers_.count(debugName) == 1);
    PerfDataSet& perfDataSet = timers_[debugName];
    perfDataSet.cpuTimer.Begin();
#if (RENDER_GPU_TIMESTAMP_QUERIES_ENABLED == 1)
    if (validGpuQueries_) {
#ifdef GL_GPU_DISJOINT_EXT
        /* Clear disjoint error */
        GLint disjointOccurred = 0;
        glGetIntegerv(GL_GPU_DISJOINT_EXT, &disjointOccurred);
#endif
        GpuQuery* gpuQuery = gpuQueryMgr_->Get(perfDataSet.gpuHandle);
        PLUGIN_ASSERT(gpuQuery);

        const auto& platData = static_cast<const GpuQueryPlatformDataGLES&>(gpuQuery->GetPlatformData());
        PLUGIN_ASSERT(platData.queryObject);
        glBeginQuery(GL_TIME_ELAPSED_EXT, platData.queryObject);
    }
#endif // RENDER_GPU_TIMESTAMP_QUERIES_ENABLED
#endif // RENDER_PERF_ENABLED
#if (RENDER_DEBUG_MARKERS_ENABLED == 1)
    glPushDebugGroup(GL_DEBUG_SOURCE_APPLICATION, 0, -1, (const GLchar*)debugName.data());
#endif
    commandListValid_ = true;
    for (const auto& ref : renderCommandCtx.renderCommandList->GetRenderCommands()) {
        PLUGIN_ASSERT(ref.rc);
        if (commandListValid_) {
#if RENDER_DEBUG_COMMAND_MARKERS_ENABLED
            glPushDebugGroup(GL_DEBUG_SOURCE_APPLICATION, 0, -1, (const GLchar*)COMMAND_NAMES[(uint32_t)ref.type]);
#endif
            (this->*(COMMAND_HANDLERS[static_cast<uint32_t>(ref.type)]))(ref);
#if RENDER_DEBUG_COMMAND_MARKERS_ENABLED
            glPopDebugGroup();
#endif
        }
    }
#if (RENDER_DEBUG_MARKERS_ENABLED == 1)
    glPopDebugGroup();
#endif
#if (RENDER_PERF_ENABLED == 1)
#if (RENDER_GPU_TIMESTAMP_QUERIES_ENABLED == 1)
    if (validGpuQueries_) {
        glEndQuery(GL_TIME_ELAPSED_EXT);
    }
#endif // RENDER_GPU_TIMESTAMP_QUERIES_ENABLED
    perfDataSet.cpuTimer.End();
    CopyPerfTimeStamp(debugName, perfDataSet);
#endif // RENDER_PERF_ENABLED
}

void RenderBackendGLES::RenderCommandBindPipeline(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::BIND_PIPELINE);
    const auto& renderCmd = *static_cast<const struct RenderCommandBindPipeline*>(ref.rc);
    boundProgram_ = {};
    if (renderCmd.pipelineBindPoint == PipelineBindPoint::CORE_PIPELINE_BIND_POINT_COMPUTE) {
        PLUGIN_ASSERT(currentFrameBuffer_ == nullptr);
        BindComputePipeline(renderCmd);
    } else if (renderCmd.pipelineBindPoint == PipelineBindPoint::CORE_PIPELINE_BIND_POINT_GRAPHICS) {
        BindGraphicsPipeline(renderCmd);
    }
    currentPsoHandle_ = renderCmd.psoHandle;
}

void RenderBackendGLES::BindComputePipeline(const struct RenderCommandBindPipeline& renderCmd)
{
    const auto* pso = static_cast<const ComputePipelineStateObjectGLES*>(
        managers_.psoMgr->GetComputePso(renderCmd.psoHandle, nullptr));
    if (pso) {
        const auto& data = static_cast<const PipelineStateObjectPlatformDataGL&>(pso->GetPlatformData());
        // Setup descriptorset bind cache..
        SetupCache(data.pipelineLayout);
    }
    boundComputePipeline_ = pso;
    boundGraphicsPipeline_ = nullptr;
}

void RenderBackendGLES::SetupCache(const PipelineLayout& pipelineLayout)
{
    // based on pipeline layout. (note that compatible sets should "save state")
    for (uint32_t set = 0; set < PipelineLayoutConstants::MAX_DESCRIPTOR_SET_COUNT; ++set) {
        // mark unmatching sets dirty (all for now)
        // resize the cache stuffs.
        const auto& s = pipelineLayout.descriptorSetLayouts[set];
        if (s.set == PipelineLayoutConstants::INVALID_INDEX) {
            boundObjects_[set].dirty = true;
#if RENDER_HAS_GLES_BACKEND
            boundObjects_[set].oesBinds.clear();
#endif
            boundObjects_[set].resources.clear();
            continue;
        }
        PLUGIN_ASSERT(s.set == set);

        uint32_t maxB = 0;
        // NOTE: compatibility optimizations?
        // NOTE: we expect bindings to be sorted.
        if (s.bindings.back().binding == s.bindings.size() - 1U) {
            // since the last binding matches the size, expect it to be continuous.
            maxB = static_cast<uint32_t>(s.bindings.size());
        } else {
            // Sparse binding.
            // NOTE: note sparse sets will waste memory here. (see notes in
            // https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/VkDescriptorSetLayoutBinding.html)
            for (const auto& bind : s.bindings) {
                maxB = Math::max(maxB, bind.binding);
            }
            maxB += 1U; // zero based bindings..
        }
        if (boundObjects_[set].resources.size() != maxB) {
            // resource count change.. (so it's dirty then)
            boundObjects_[set].dirty = true;
#if RENDER_HAS_GLES_BACKEND
            boundObjects_[set].oesBinds.clear();
#endif
            boundObjects_[set].resources.clear(); // clear because we don't care what it had before.
            boundObjects_[set].resources.resize(maxB);
        }

        for (const auto& b : s.bindings) {
            auto& o = boundObjects_[set].resources[b.binding];
            // ignore b.shaderStageFlags for now.
            if ((o.resources.size() != b.descriptorCount) || (o.descriptorType != b.descriptorType)) {
                // mark set dirty, since "not matching"
                o.resources.clear();
                o.resources.resize(b.descriptorCount);
                o.descriptorType = b.descriptorType;
                boundObjects_[set].dirty = true;
#if RENDER_HAS_GLES_BACKEND
                boundObjects_[set].oesBinds.clear();
#endif
            }
        }
    }
}

void RenderBackendGLES::BindGraphicsPipeline(const struct RenderCommandBindPipeline& renderCmd)
{
    const auto* pso = static_cast<const GraphicsPipelineStateObjectGLES*>(
        managers_.psoMgr->GetGraphicsPso(renderCmd.psoHandle, activeRenderPass_.renderPassDesc,
            activeRenderPass_.subpasses, activeRenderPass_.subpassStartIndex, 0, nullptr, nullptr));
    if (pso) {
        const auto& data = static_cast<const PipelineStateObjectPlatformDataGL&>(pso->GetPlatformData());
        dynamicStateFlags_ = data.dynamicStateFlags;
        DoGraphicsState(data.graphicsState);
        // NOTE: Deprecate (default viewport/scissor should be set from default targets at some point)
        if (!IS_BIT(dynamicStateFlags_, CORE_DYNAMIC_STATE_VIEWPORT)) {
            SetViewport(renderArea_, ViewportDesc { 0.0f, 0.0f, static_cast<float>(renderArea_.extentWidth),
                                         static_cast<float>(renderArea_.extentHeight), 0.0f, 1.0f });
        }
        if (!IS_BIT(dynamicStateFlags_, CORE_DYNAMIC_STATE_SCISSOR)) {
            SetScissor(renderArea_, ScissorDesc { 0, 0, renderArea_.extentWidth, renderArea_.extentHeight });
        }
        // Setup descriptorset bind cache..
        SetupCache(data.pipelineLayout);
    }
    boundComputePipeline_ = nullptr;
    boundGraphicsPipeline_ = pso;
}

void RenderBackendGLES::RenderCommandDraw(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::DRAW);
    const auto& renderCmd = *static_cast<struct RenderCommandDraw*>(ref.rc);
    if (!boundGraphicsPipeline_) {
        return;
    }
    PLUGIN_ASSERT(boundComputePipeline_ == nullptr);
    BindResources();
    const auto type = GetPrimFromTopology(topology_);
    const GLsizei firstVertex = static_cast<const GLsizei>(renderCmd.firstVertex);
    const GLsizei instanceCount = static_cast<GLsizei>(renderCmd.instanceCount);
    // firstInstance is not supported yet, need to set the SPIRV_Cross generated uniform
    // "SPIRV_Cross_BaseInstance" to renderCmd.firstInstance;
    if (renderCmd.indexCount) {
        uintptr_t offsetp = boundIndexBuffer_.offset;
        GLenum indexType = GL_UNSIGNED_SHORT;
        switch (boundIndexBuffer_.type) {
            case CORE_INDEX_TYPE_UINT16:
                offsetp += renderCmd.firstIndex * sizeof(uint16_t);
                indexType = GL_UNSIGNED_SHORT;
                break;
            case CORE_INDEX_TYPE_UINT32:
                offsetp += renderCmd.firstIndex * sizeof(uint32_t);
                indexType = GL_UNSIGNED_INT;
                break;
            default:
                PLUGIN_ASSERT_MSG(false, "Invalid indexbuffer type");
                break;
        }
        const GLsizei indexCount = static_cast<const GLsizei>(renderCmd.indexCount);
        const void* offset = reinterpret_cast<const void*>(offsetp);
        if (renderCmd.instanceCount > 1) {
            if (renderCmd.firstVertex) {
                glDrawElementsInstancedBaseVertex(type, indexCount, indexType, offset, instanceCount, firstVertex);
            } else {
                glDrawElementsInstanced(type, indexCount, indexType, offset, instanceCount);
            }
        } else {
            if (renderCmd.vertexOffset) {
                glDrawElementsBaseVertex(
                    type, indexCount, indexType, offset, static_cast<GLint>(renderCmd.vertexOffset));
            } else {
                glDrawElements(type, indexCount, indexType, offset);
            }
        }
#if (RENDER_PERF_ENABLED == 1)
        ++perfCounters_.drawCount;
        perfCounters_.instanceCount += renderCmd.instanceCount;
        perfCounters_.triangleCount += renderCmd.indexCount * renderCmd.instanceCount;
#endif
    } else {
        const GLsizei vertexCount = static_cast<const GLsizei>(renderCmd.vertexCount);
        if (renderCmd.instanceCount > 1) {
            glDrawArraysInstanced(type, firstVertex, vertexCount, instanceCount);
        } else {
            glDrawArrays(type, firstVertex, vertexCount);
        }
#if (RENDER_PERF_ENABLED == 1)
        ++perfCounters_.drawCount;
        perfCounters_.instanceCount += renderCmd.instanceCount;
        perfCounters_.triangleCount += (renderCmd.vertexCount * 3) * renderCmd.instanceCount; // 3: vertex dimension
#endif
    }
}

void RenderBackendGLES::RenderCommandDrawIndirect(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::DRAW_INDIRECT);
    const auto& renderCmd = *static_cast<const struct RenderCommandDrawIndirect*>(ref.rc);
    if (!boundGraphicsPipeline_) {
        return;
    }
    PLUGIN_ASSERT(boundComputePipeline_ == nullptr);
    BindResources();
    if (const GpuBufferGLES* gpuBuffer = gpuResourceMgr_.GetBuffer<GpuBufferGLES>(renderCmd.argsHandle); gpuBuffer) {
        const auto& plat = gpuBuffer->GetPlatformData();
        device_.BindBuffer(GL_DRAW_INDIRECT_BUFFER, plat.buffer);
        const auto type = GetPrimFromTopology(topology_);
        auto offset = static_cast<GLintptr>(renderCmd.offset);
        if (renderCmd.drawType == DrawType::DRAW_INDEXED_INDIRECT) {
            GLenum indexType = GL_UNSIGNED_SHORT;
            switch (boundIndexBuffer_.type) {
                case CORE_INDEX_TYPE_UINT16:
                    indexType = GL_UNSIGNED_SHORT;
                    break;
                case CORE_INDEX_TYPE_UINT32:
                    indexType = GL_UNSIGNED_INT;
                    break;
                default:
                    PLUGIN_ASSERT_MSG(false, "Invalid indexbuffer type");
                    break;
            }
            for (uint32_t i = 0; i < renderCmd.drawCount; ++i) {
                glDrawElementsIndirect(type, indexType, reinterpret_cast<const void*>(offset));
                offset += renderCmd.stride;
            }
        } else {
            for (uint32_t i = 0; i < renderCmd.drawCount; ++i) {
                glDrawArraysIndirect(type, reinterpret_cast<const void*>(offset));
                offset += renderCmd.stride;
            }
        }
#if (RENDER_PERF_ENABLED == 1)
        perfCounters_.drawIndirectCount += renderCmd.drawCount;
#endif
    }
}

void RenderBackendGLES::RenderCommandDispatch(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::DISPATCH);
    const auto& renderCmd = *static_cast<const struct RenderCommandDispatch*>(ref.rc);
    if (!boundComputePipeline_) {
        return;
    }
    PLUGIN_ASSERT(boundGraphicsPipeline_ == nullptr);
    BindResources();
    glDispatchCompute(renderCmd.groupCountX, renderCmd.groupCountY, renderCmd.groupCountZ);
#if (RENDER_PERF_ENABLED == 1)
    ++perfCounters_.dispatchCount;
#endif
}

void RenderBackendGLES::RenderCommandDispatchIndirect(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::DISPATCH_INDIRECT);
    const auto& renderCmd = *static_cast<const struct RenderCommandDispatchIndirect*>(ref.rc);
    if (!boundComputePipeline_) {
        return;
    }
    PLUGIN_ASSERT(boundGraphicsPipeline_ == nullptr);
    BindResources();
    if (const GpuBufferGLES* gpuBuffer = gpuResourceMgr_.GetBuffer<GpuBufferGLES>(renderCmd.argsHandle); gpuBuffer) {
        const auto& plat = gpuBuffer->GetPlatformData();
        device_.BindBuffer(GL_DISPATCH_INDIRECT_BUFFER, plat.buffer);
        glDispatchComputeIndirect(static_cast<GLintptr>(renderCmd.offset));
#if (RENDER_PERF_ENABLED == 1)
        ++perfCounters_.dispatchIndirectCount;
#endif
    }
}

void RenderBackendGLES::ClearScissorInit(const RenderPassDesc::RenderArea& aArea)
{
    resetScissor_ = false;           // need to reset scissor state after clear?
    clearScissorSet_ = true;         // need to setup clear scissors before clear?
    clearScissor_ = aArea;           // area to be cleared
    if (scissorPrimed_) {            // have scissors been set yet?
        if ((!scissorBoxUpdated_) && // if there is a pending scissor change, ignore the scissorbox.
            (clearScissor_.offsetX == scissorBox_.offsetX) && (clearScissor_.offsetY == scissorBox_.offsetY) &&
            (clearScissor_.extentWidth == scissorBox_.extentWidth) &&
            (clearScissor_.extentHeight == scissorBox_.extentHeight)) {
            // Current scissors match clearscissor area, so no need to set it again.
            clearScissorSet_ = false;
        }
    }
}

void RenderBackendGLES::ClearScissorSet()
{
    if (clearScissorSet_) {       // do we need to set clear scissors.
        clearScissorSet_ = false; // clear scissors have been set now.
        resetScissor_ = true;     // we are modifying scissors, so remember to reset them afterwards.
        glScissor(static_cast<GLint>(clearScissor_.offsetX), static_cast<GLint>(clearScissor_.offsetY),
            static_cast<GLsizei>(clearScissor_.extentWidth), static_cast<GLsizei>(clearScissor_.extentHeight));
    }
}

void RenderBackendGLES::ClearScissorReset()
{
    if (resetScissor_) { // need to reset correct scissors?
        if (!scissorPrimed_) {
            // scissors have not been set yet, so use clearbox as current cache state (and don't change scissor
            // setting)
            scissorPrimed_ = true;
            scissorBox_.offsetX = clearScissor_.offsetX;
            scissorBox_.offsetY = clearScissor_.offsetY;
            scissorBox_.extentHeight = clearScissor_.extentHeight;
            scissorBox_.extentWidth = clearScissor_.extentWidth;
        } else {
            // Restore scissor box to cached state. (update scissors when needed, since clearBox != scissorBox)
            scissorBoxUpdated_ = true; // ie. request to update scissor state.
        }
    }
}

void RenderBackendGLES::HandleColorAttachments(const array_view<const RenderPassDesc::AttachmentDesc*> colorAttachments)
{
    constexpr ColorComponentFlags clearAll = CORE_COLOR_COMPONENT_R_BIT | CORE_COLOR_COMPONENT_G_BIT |
                                             CORE_COLOR_COMPONENT_B_BIT | CORE_COLOR_COMPONENT_A_BIT;
    const auto& cBlend = cacheState_.colorBlendState;
    for (uint32_t idx = 0; idx < colorAttachments.size(); ++idx) {
        if (colorAttachments[idx] == nullptr) {
            continue;
        }
        const auto& ref = *(colorAttachments[idx]);
        if (ref.loadOp == AttachmentLoadOp::CORE_ATTACHMENT_LOAD_OP_CLEAR) {
            const auto& cBlendState = cBlend.colorAttachments[idx];
            if (clearAll != cBlendState.colorWriteMask) {
                glColorMaski(idx, GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
            }
            ClearScissorSet();
            // glClearBufferfv only for float formats?
            // glClearBufferiv & glClearbufferuv only for integer formats?
            glClearBufferfv(GL_COLOR, static_cast<GLint>(idx), ref.clearValue.color.float32);
            if (clearAll != cBlendState.colorWriteMask) {
                // NOTE: We might not need to restore here.. (we need to peek in to the command list to find out...)
                glColorMaski(idx, IS_BIT_GL(cBlendState.colorWriteMask, CORE_COLOR_COMPONENT_R_BIT),
                    IS_BIT_GL(cBlendState.colorWriteMask, CORE_COLOR_COMPONENT_G_BIT),
                    IS_BIT_GL(cBlendState.colorWriteMask, CORE_COLOR_COMPONENT_B_BIT),
                    IS_BIT_GL(cBlendState.colorWriteMask, CORE_COLOR_COMPONENT_A_BIT));
            }
        }
    }
}

void RenderBackendGLES::HandleDepthAttachment(const RenderPassDesc::AttachmentDesc& depthAttachment)
{
    const GLuint allBits = 0xFFFFFFFFu;
    const auto& ref = depthAttachment;
    const bool clearDepth = (ref.loadOp == AttachmentLoadOp::CORE_ATTACHMENT_LOAD_OP_CLEAR);
    const bool clearStencil = (ref.stencilLoadOp == AttachmentLoadOp::CORE_ATTACHMENT_LOAD_OP_CLEAR);
    // Change state if needed.
    if ((clearDepth) && (!cacheState_.depthStencilState.enableDepthWrite)) {
        glDepthMask(GL_TRUE);
    }
    if (clearStencil) {
        if (cacheState_.depthStencilState.frontStencilOpState.writeMask != allBits) {
            glStencilMaskSeparate(GL_FRONT, allBits);
        }
        if (cacheState_.depthStencilState.backStencilOpState.writeMask != allBits) {
            glStencilMaskSeparate(GL_BACK, allBits);
        }
    }
    if (clearDepth || clearStencil) {
        // Set the scissors for clear..
        ClearScissorSet();
    }
    // Do clears.
    if (clearDepth && clearStencil) {
        glClearBufferfi(GL_DEPTH_STENCIL, 0, ref.clearValue.depthStencil.depth,
            static_cast<GLint>(ref.clearValue.depthStencil.stencil));
    } else if (clearDepth) {
        glClearBufferfv(GL_DEPTH, 0, &ref.clearValue.depthStencil.depth);
    } else if (clearStencil) {
        glClearBufferiv(GL_STENCIL, 0, reinterpret_cast<const GLint*>(&ref.clearValue.depthStencil.stencil));
    }

    // Restore cached state, if we touched the state.
    if ((clearDepth) && (!cacheState_.depthStencilState.enableDepthWrite)) {
        // NOTE: We might not need to restore here.. (we need to peek in to the command list to find out...)
        glDepthMask(GL_FALSE);
    }
    if (clearStencil) {
        // NOTE: We might not need to restore here.. (we need to peek in to the command list to find out...)
        if (cacheState_.depthStencilState.frontStencilOpState.writeMask != allBits) {
            glStencilMaskSeparate(GL_FRONT, cacheState_.depthStencilState.frontStencilOpState.writeMask);
        }
        if (cacheState_.depthStencilState.backStencilOpState.writeMask != allBits) {
            glStencilMaskSeparate(GL_BACK, cacheState_.depthStencilState.backStencilOpState.writeMask);
        }
    }
}

void RenderBackendGLES::DoSubPass(uint32_t subPass)
{
    if (currentFrameBuffer_ == nullptr) {
        // Completely invalid state in backend.
        return;
    }
    const auto& rpd = activeRenderPass_.renderPassDesc;
    const auto& sb = activeRenderPass_.subpasses[subPass];

    // If there's no FBO activate the with swapchain handle so that drawing happens to the correct surface.
    if (!currentFrameBuffer_->fbos[subPass].fbo && (sb.colorAttachmentCount == 1U)) {
        auto color = rpd.attachmentHandles[sb.colorAttachmentIndices[0]];
        device_.Activate(color);
    }
    device_.BindFrameBuffer(currentFrameBuffer_->fbos[subPass].fbo);
    ClearScissorInit(renderArea_);
    if (cacheState_.rasterizationState.enableRasterizerDiscard) { // Rasterizer discard affects glClearBuffer*
        SetState(GL_RASTERIZER_DISCARD, GL_FALSE);
    }
    {
        // NOTE: clear is not yet optimal. depth, stencil and color should be cleared using ONE glClear call if
        // possible. (ie. all buffers at once)
        renderingToDefaultFbo_ = false;
        if (sb.colorAttachmentCount > 0) {
            // collect color attachment infos..
            const RenderPassDesc::AttachmentDesc*
                colorAttachments[PipelineStateConstants::MAX_RENDER_PASS_ATTACHMENT_COUNT];
            for (uint32_t ci = 0; ci < sb.colorAttachmentCount; ci++) {
                uint32_t index = sb.colorAttachmentIndices[ci];
                if (resolveToBackbuffer_[index]) {
                    // NOTE: this could fail with multiple color attachments....
                    renderingToDefaultFbo_ = true;
                }
                if (!attachmentCleared_[index]) {
                    attachmentCleared_[index] = true;
                    colorAttachments[ci] = &rpd.attachments[index];
                } else {
                    colorAttachments[ci] = nullptr;
                }
            }
            HandleColorAttachments(array_view(colorAttachments, sb.colorAttachmentCount));
        }
        if (sb.depthAttachmentCount) {
            if (!attachmentCleared_[sb.depthAttachmentIndex]) {
                attachmentCleared_[sb.depthAttachmentIndex] = true;
                HandleDepthAttachment(rpd.attachments[sb.depthAttachmentIndex]);
            }
        }
    }
    if (cacheState_.rasterizationState.enableRasterizerDiscard) { // Rasterizer discard affects glClearBuffer*
        // NOTE: We might not need to restore here.. (we need to peek in to the command list to find out...)
        SetState(GL_RASTERIZER_DISCARD, GL_TRUE);
    }
    ClearScissorReset();
}

void RenderBackendGLES::ScanPasses(const RenderPassDesc& rpd)
{
    for (uint32_t sub = 0; sub < rpd.subpassCount; sub++) {
        const auto& currentSubPass = activeRenderPass_.subpasses[sub];
        for (uint32_t ci = 0; ci < currentSubPass.resolveAttachmentCount; ci++) {
            uint32_t resolveTo = currentSubPass.resolveAttachmentIndices[ci];
            if (attachmentFirstUse_[resolveTo] == 0xFFFFFFFF) {
                attachmentFirstUse_[resolveTo] = sub;
            }
            attachmentLastUse_[resolveTo] = sub;
            const auto& p = static_cast<const GpuImagePlatformDataGL&>(attachmentImage_[resolveTo]->GetPlatformData());
            if ((p.image == 0) && (p.renderBuffer == 0)) {
                // mark the "resolveFrom" (ie. the colorattachment) as "backbuffer-like", since we resolve to
                // backbuffer...
                uint32_t resolveFrom = currentSubPass.colorAttachmentIndices[ci];
                resolveToBackbuffer_[resolveFrom] = true;
            }
        }
        for (uint32_t ci = 0; ci < currentSubPass.inputAttachmentCount; ci++) {
            uint32_t index = currentSubPass.inputAttachmentIndices[ci];
            if (attachmentFirstUse_[index] == 0xFFFFFFFF) {
                attachmentFirstUse_[index] = sub;
            }
            attachmentLastUse_[index] = sub;
        }
        for (uint32_t ci = 0; ci < currentSubPass.colorAttachmentCount; ci++) {
            uint32_t index = currentSubPass.colorAttachmentIndices[ci];
            if (attachmentFirstUse_[index] == 0xFFFFFFFF) {
                attachmentFirstUse_[index] = sub;
            }
            attachmentLastUse_[index] = sub;
            if (attachmentImage_[index]) {
                const auto& p = static_cast<const GpuImagePlatformDataGL&>(attachmentImage_[index]->GetPlatformData());
                if ((p.image == 0) && (p.renderBuffer == 0)) {
                    resolveToBackbuffer_[index] = true;
                }
            }
        }
        if (currentSubPass.depthAttachmentCount > 0) {
            uint32_t index = currentSubPass.depthAttachmentIndex;
            if (attachmentFirstUse_[index] == 0xFFFFFFFF) {
                attachmentFirstUse_[index] = sub;
            }
            attachmentLastUse_[index] = sub;
        }
    }
}

void RenderBackendGLES::RenderCommandBeginRenderPass(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::BEGIN_RENDER_PASS);
    const auto& renderCmd = *static_cast<const struct RenderCommandBeginRenderPass*>(ref.rc);
    switch (renderCmd.beginType) {
        case RenderPassBeginType::RENDER_PASS_BEGIN: {
            ++inRenderpass_;
            PLUGIN_ASSERT_MSG(inRenderpass_ == 1, "RenderBackendGLES beginrenderpass mInRenderpass %u", inRenderpass_);
            activeRenderPass_ = renderCmd; // Store this because we need it later (in NextRenderPass)

            const auto& rpd = activeRenderPass_.renderPassDesc;
            renderArea_ = rpd.renderArea; // can subpasses have different render areas?
            auto& cpm = *(static_cast<NodeContextPoolManagerGLES*>(managers_.poolMgr));
            if (multisampledRenderToTexture_) {
                cpm.FilterRenderPass(activeRenderPass_);
            }
            currentFrameBuffer_ = cpm.GetFramebuffer(cpm.GetFramebufferHandle(activeRenderPass_));
            if (currentFrameBuffer_ == nullptr) {
                // Completely invalid state in backend.
                commandListValid_ = false;
                --inRenderpass_;
                return;
            }
            PLUGIN_ASSERT_MSG(
                activeRenderPass_.subpassStartIndex == 0, "activeRenderPass_.subpassStartIndex != 0 not handled!");
            currentSubPass_ = 0;
            // find first and last use, clear clearflags. (this could be cached in the lowlewel classes)
            for (uint32_t i = 0; i < rpd.attachmentCount; i++) {
                attachmentCleared_[i] = false;
                attachmentFirstUse_[i] = 0xFFFFFFFF;
                attachmentLastUse_[i] = 0;
                resolveToBackbuffer_[i] = false;
                attachmentImage_[i] =
                    static_cast<const GpuImageGLES*>(gpuResourceMgr_.GetImage(rpd.attachmentHandles[i]));
            }
            ScanPasses(rpd);
            DoSubPass(0);
#if (RENDER_PERF_ENABLED == 1)
            ++perfCounters_.renderPassCount;
#endif
        } break;

        case RenderPassBeginType::RENDER_PASS_SUBPASS_BEGIN: {
            ++currentSubPass_;
            PLUGIN_ASSERT(currentSubPass_ < activeRenderPass_.renderPassDesc.subpassCount);
            DoSubPass(activeRenderPass_.subpassStartIndex);
        } break;

        default:
            break;
    }
}

void RenderBackendGLES::RenderCommandNextSubpass(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::NEXT_SUBPASS);
    const auto& renderCmd = *static_cast<const struct RenderCommandNextSubpass*>(ref.rc);
    PLUGIN_UNUSED(renderCmd);
    PLUGIN_ASSERT(renderCmd.subpassContents == SubpassContents::CORE_SUBPASS_CONTENTS_INLINE);
    ++currentSubPass_;
    PLUGIN_ASSERT(currentSubPass_ < activeRenderPass_.renderPassDesc.subpassCount);
    DoSubPass(currentSubPass_);
}

int32_t RenderBackendGLES::InvalidateDepthStencil(
    array_view<uint32_t> invalidateAttachment, const RenderPassDesc& rpd, const RenderPassSubpassDesc& currentSubPass)
{
    int32_t depthCount = 0;
    if (currentSubPass.depthAttachmentCount > 0) {
        const uint32_t index = currentSubPass.depthAttachmentIndex;
        if (attachmentLastUse_[index] == currentSubPass_) { // is last use of the attachment
            const auto& image = attachmentImage_[index];
            const auto& dplat = static_cast<const GpuImagePlatformDataGL&>(image->GetPlatformData());
            // NOTE: we expect the depth to be in FBO in this case even if there would be a depth target in render pass
            if ((dplat.image || dplat.renderBuffer) && (!renderingToDefaultFbo_)) {
                bool depth = false;
                bool stencil = false;
                if (rpd.attachments[index].storeOp == CORE_ATTACHMENT_STORE_OP_DONT_CARE) {
                    if ((dplat.format == GL_DEPTH_COMPONENT) || (dplat.format == GL_DEPTH_STENCIL)) {
                        depth = true;
                    }
                }
                if (rpd.attachments[index].stencilStoreOp == CORE_ATTACHMENT_STORE_OP_DONT_CARE) {
                    if ((dplat.format == GL_STENCIL) || (dplat.format == GL_DEPTH_STENCIL)) {
                        stencil = true;
                    }
                }
                if (depth && stencil) {
                    invalidateAttachment[0] = GL_DEPTH_STENCIL_ATTACHMENT;
                    depthCount++;
                } else if (stencil) {
                    invalidateAttachment[0] = GL_STENCIL_ATTACHMENT;
                    depthCount++;
                } else if (depth) {
                    invalidateAttachment[0] = GL_DEPTH_ATTACHMENT;
                    depthCount++;
                }
            }
        }
    }
    return depthCount;
}

int32_t RenderBackendGLES::InvalidateColor(
    array_view<uint32_t> invalidateAttachment, const RenderPassDesc& rpd, const RenderPassSubpassDesc& currentSubPass)
{
    int32_t colorCount = 0;
    // see which parts of the fbo can be invalidated...
    // collect color attachment infos..
    for (uint32_t ci = 0; ci < currentSubPass.colorAttachmentCount; ci++) {
        const uint32_t index = currentSubPass.colorAttachmentIndices[ci];
        if (attachmentLastUse_[index] == currentSubPass_) { // is last use of the attachment
            if (const auto* image = attachmentImage_[index]) {
                const auto& dplat = static_cast<const GpuImagePlatformDataGL&>(image->GetPlatformData());
                if (dplat.image || dplat.renderBuffer) {
                    if (rpd.attachments[index].storeOp == CORE_ATTACHMENT_STORE_OP_DONT_CARE) {
                        invalidateAttachment[static_cast<size_t>(colorCount)] = GL_COLOR_ATTACHMENT0 + ci;
                        colorCount++;
                    }
                }
            }
        }
    }
    return colorCount;
}

uint32_t RenderBackendGLES::ResolveMSAA(const RenderPassDesc& rpd, const RenderPassSubpassDesc& currentSubPass)
{
    const GLbitfield mask = ((currentSubPass.resolveAttachmentCount > 0u) ? GL_COLOR_BUFFER_BIT : 0u) |
                            ((currentSubPass.depthResolveAttachmentCount > 0u) ? GL_DEPTH_BUFFER_BIT : 0u);
    if (mask) {
        // Resolve MSAA buffers.
        // NOTE: ARM recommends NOT to use glBlitFramebuffer here
        device_.BindReadFrameBuffer(currentFrameBuffer_->fbos[currentSubPass_].fbo);
        device_.BindWriteFrameBuffer(currentFrameBuffer_->fbos[currentSubPass_].resolve);
        if (scissorEnabled_) {
            glDisable(GL_SCISSOR_TEST);
            scissorEnabled_ = false;
        }
        // FLIP_RESOLVE_DEFAULT_FBO not needed, since we render flipped if end result will be resolved to fbo..
        // hopefully it works now.
#if defined(FLIP_RESOLVE_DEFAULT_FBO) && FLIP_RESOLVE_DEFAULT_FBO
        if (currentFrameBuffer_->resolveFbo[currentSubPass_] == 0) {
            // flip if resolving to default fbo. (NOTE: sample count of destination must be zero or equal to source)
            // and in mali devices src and dst rects MUST be equal. (which is not according to spec)
            // IE. can't flip and resolve at the same time on MALI based devices.
            // NEED A FIX HERE!
            glBlitFramebuffer(0, 0, static_cast<GLint>(currentFrameBuffer_->width),
                static_cast<GLint>(currentFrameBuffer_->height), 0, static_cast<GLint>(currentFrameBuffer_->height),
                static_cast<GLint>(currentFrameBuffer_->width), 0, mask, GL_NEAREST);
            return GL_READ_FRAMEBUFFER;
        }
#endif
        glBlitFramebuffer(0, 0, static_cast<GLint>(currentFrameBuffer_->width),
            static_cast<GLint>(currentFrameBuffer_->height), 0, 0, static_cast<GLint>(currentFrameBuffer_->width),
            static_cast<GLint>(currentFrameBuffer_->height), mask,
            GL_NEAREST); // no flip
        return GL_READ_FRAMEBUFFER;
    }
    return GL_FRAMEBUFFER;
}

void RenderBackendGLES::RenderCommandEndRenderPass(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::END_RENDER_PASS);
    const auto& renderCmd = *static_cast<const struct RenderCommandEndRenderPass*>(ref.rc);
    if (renderCmd.endType == RenderPassEndType::END_RENDER_PASS) {
        PLUGIN_ASSERT_MSG(inRenderpass_ == 1, "RenderBackendGLES endrenderpass mInRenderpass %u", inRenderpass_);
        inRenderpass_--;
    }
    if (currentFrameBuffer_ == nullptr) {
        // Completely invalid state in backend.
        return;
    }
    const auto& rpd = activeRenderPass_.renderPassDesc;
    const auto& currentSubPass = activeRenderPass_.subpasses[currentSubPass_];

    // Resolve MSAA
    const uint32_t fbType = ResolveMSAA(rpd, currentSubPass);

    // Finally invalidate color and depth..
    GLenum invalidate[PipelineStateConstants::MAX_COLOR_ATTACHMENT_COUNT + 1] = {};
    int32_t invalidateCount = InvalidateColor(invalidate, rpd, currentSubPass);
    invalidateCount += InvalidateDepthStencil(
        array_view(invalidate + invalidateCount, countof(invalidate) - invalidateCount), rpd, currentSubPass);

    // NOTE: all attachments should be the same size AND mCurrentFrameBuffer->width/height should match that!
    Invalidate(fbType, invalidateCount, invalidate, rpd, *currentFrameBuffer_);

    if (inRenderpass_ == 0) {
        currentFrameBuffer_ = nullptr;
    }
}

void RenderBackendGLES::RenderCommandBindVertexBuffers(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::BIND_VERTEX_BUFFERS);
    const auto& renderCmd = *static_cast<const struct RenderCommandBindVertexBuffers*>(ref.rc);
    PLUGIN_ASSERT(renderCmd.vertexBufferCount > 0);
    PLUGIN_ASSERT(renderCmd.vertexBufferCount <= PipelineStateConstants::MAX_VERTEX_BUFFER_COUNT);
    if (!boundGraphicsPipeline_) {
        return;
    }
    vertexAttribBinds_ = renderCmd.vertexBufferCount;
    for (size_t i = 0; i < renderCmd.vertexBufferCount; i++) {
        const auto& currVb = renderCmd.vertexBuffers[i];
        if (const auto* gpuBuffer = gpuResourceMgr_.GetBuffer<GpuBufferGLES>(currVb.bufferHandle); gpuBuffer) {
            const auto& plat = gpuBuffer->GetPlatformData();
            uintptr_t offset = currVb.bufferOffset;
            offset += plat.currentByteOffset;
            vertexAttribBindSlots_[i].id = plat.buffer;
            vertexAttribBindSlots_[i].offset = static_cast<intptr_t>(offset);
        } else {
            vertexAttribBindSlots_[i].id = 0;
            vertexAttribBindSlots_[i].offset = 0;
        }
    }
}

void RenderBackendGLES::RenderCommandBindIndexBuffer(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::BIND_INDEX_BUFFER);
    const auto& renderCmd = *static_cast<const struct RenderCommandBindIndexBuffer*>(ref.rc);
    if (const GpuBufferGLES* gpuBuffer = gpuResourceMgr_.GetBuffer<GpuBufferGLES>(renderCmd.indexBuffer.bufferHandle);
        gpuBuffer) {
        const auto& plat = gpuBuffer->GetPlatformData();
        boundIndexBuffer_.offset = renderCmd.indexBuffer.bufferOffset;
        boundIndexBuffer_.offset += plat.currentByteOffset;
        boundIndexBuffer_.type = renderCmd.indexBuffer.indexType;
        boundIndexBuffer_.id = plat.buffer;
    }
}

void RenderBackendGLES::RenderCommandBlitImage(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::BLIT_IMAGE);
    const auto& renderCmd = *static_cast<const struct RenderCommandBlitImage*>(ref.rc);
    const auto* srcImage = gpuResourceMgr_.GetImage<GpuImageGLES>(renderCmd.srcHandle);
    const auto* dstImage = gpuResourceMgr_.GetImage<GpuImageGLES>(renderCmd.dstHandle);
    if ((srcImage == nullptr) || (dstImage == nullptr)) {
        return;
    }
    const auto& srcDesc = srcImage->GetDesc();
    const auto& srcPlat = srcImage->GetPlatformData();
    const auto& dstDesc = dstImage->GetDesc();
    const auto& dstPlat = dstImage->GetPlatformData();
    const auto& srcRect = renderCmd.imageBlit.srcOffsets;
    const auto& dstRect = renderCmd.imageBlit.dstOffsets;
    const auto& src = renderCmd.imageBlit.srcSubresource;
    const auto& dst = renderCmd.imageBlit.dstSubresource;
    const GLint srcMipLevel = static_cast<GLint>(src.mipLevel);
    const GLint dstMipLevel = static_cast<GLint>(dst.mipLevel);
    const uint32_t srcSampleCount = static_cast<uint32_t>(srcDesc.sampleCountFlags);
    const uint32_t dstSampleCount = static_cast<uint32_t>(dstDesc.sampleCountFlags);
    PLUGIN_ASSERT_MSG(src.layerCount == dst.layerCount, "Source and Destination layercounts do not match!");
    PLUGIN_ASSERT_MSG(inRenderpass_ == 0, "RenderCommandBlitImage while inRenderPass");
    glDisable(GL_SCISSOR_TEST);
    scissorEnabled_ = false;
    // NOTE: LAYERS! (texture arrays)
    device_.BindReadFrameBuffer(blitImageSourceFbo_);
    device_.BindWriteFrameBuffer(blitImageDestinationFbo_);
    for (uint32_t layer = 0; layer < src.layerCount; layer++) {
        const GLenum srcType = getTarget(srcPlat.type, layer, srcSampleCount);
        const GLenum dstType = getTarget(dstPlat.type, layer, dstSampleCount);
        // glFramebufferTextureLayer for array textures....
        glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, srcType, srcPlat.image, srcMipLevel);
        glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, dstType, dstPlat.image, dstMipLevel);
        DoBlit(renderCmd.filter, { src.mipLevel, srcRect[0], srcRect[1], srcDesc.height },
            { dst.mipLevel, dstRect[0], dstRect[1], dstDesc.height });
        glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, srcType, 0, 0);
        glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, dstType, 0, 0);
    }
}

void RenderBackendGLES::RenderCommandCopyBuffer(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::COPY_BUFFER);
    const auto& renderCmd = *static_cast<const struct RenderCommandCopyBuffer*>(ref.rc);
    const auto* srcGpuBuffer = gpuResourceMgr_.GetBuffer<GpuBufferGLES>(renderCmd.srcHandle);
    const auto* dstGpuBuffer = gpuResourceMgr_.GetBuffer<GpuBufferGLES>(renderCmd.dstHandle);
    if (srcGpuBuffer && dstGpuBuffer) {
        const auto& srcData = srcGpuBuffer->GetPlatformData();
        const auto& dstData = dstGpuBuffer->GetPlatformData();
        const auto oldBindR = device_.BoundBuffer(GL_COPY_READ_BUFFER);
        const auto oldBindW = device_.BoundBuffer(GL_COPY_WRITE_BUFFER);
        device_.BindBuffer(GL_COPY_READ_BUFFER, srcData.buffer);
        device_.BindBuffer(GL_COPY_WRITE_BUFFER, dstData.buffer);
        glCopyBufferSubData(GL_COPY_READ_BUFFER, GL_COPY_WRITE_BUFFER,
            static_cast<GLintptr>(renderCmd.bufferCopy.srcOffset),
            static_cast<GLintptr>(renderCmd.bufferCopy.dstOffset), static_cast<GLsizeiptr>(renderCmd.bufferCopy.size));
        device_.BindBuffer(GL_COPY_READ_BUFFER, oldBindR);
        device_.BindBuffer(GL_COPY_WRITE_BUFFER, oldBindW);
    }
}

void RenderBackendGLES::BufferToImageCopy(const struct RenderCommandCopyBufferImage& renderCmd)
{
#if (RENDER_HAS_GLES_BACKEND == 1) & defined(_WIN32)
    // use the workaround only for gles backend on windows. (pvr simulator bug)
    constexpr const bool usePixelUnpackBuffer = false;
#else
    // expect this to work, and the nvidia bug to be fixed.
    constexpr const bool usePixelUnpackBuffer = true;
#endif
    auto* srcGpuBuffer = gpuResourceMgr_.GetBuffer<GpuBufferGLES>(renderCmd.srcHandle);
    auto* dstGpuImage = gpuResourceMgr_.GetImage<GpuImageGLES>(renderCmd.dstHandle);
    if ((srcGpuBuffer == nullptr) || (dstGpuImage == nullptr)) {
        return;
    }
    const auto info = SetupBlit<usePixelUnpackBuffer>(device_, renderCmd.bufferImageCopy, *srcGpuBuffer, *dstGpuImage);
    if (info.iPlat.type == GL_TEXTURE_CUBE_MAP) {
        BlitCube(device_, info);
    } else if (info.iPlat.type == GL_TEXTURE_2D) {
        Blit2D(device_, info);
    } else if (info.iPlat.type == GL_TEXTURE_2D_ARRAY) {
        BlitArray(device_, info);
    } else if (info.iPlat.type == GL_TEXTURE_3D) {
        Blit3D(device_, info);
#if RENDER_HAS_GLES_BACKEND
    } else if (info.iPlat.type == GL_TEXTURE_EXTERNAL_OES) {
        PLUGIN_LOG_E("Tried to copy to GL_TEXTURE_EXTERNAL_OES. Ignored!");
#endif
    } else {
        PLUGIN_ASSERT_MSG(false, "RenderCommandCopyBufferImage unhandled type");
    }
    FinishBlit<usePixelUnpackBuffer>(device_, *srcGpuBuffer);
}

void RenderBackendGLES::ImageToBufferCopy(const struct RenderCommandCopyBufferImage& renderCmd)
{
    const auto& bc = renderCmd.bufferImageCopy;
    const auto* srcGpuImage = static_cast<GpuImageGLES*>(gpuResourceMgr_.GetImage(renderCmd.srcHandle));
    const auto* dstGpuBuffer = static_cast<GpuBufferGLES*>(gpuResourceMgr_.GetBuffer(renderCmd.dstHandle));
    PLUGIN_ASSERT(srcGpuImage);
    PLUGIN_ASSERT(dstGpuBuffer);
    if ((srcGpuImage == nullptr) || (dstGpuBuffer == nullptr)) {
        return;
    }
    const auto& iPlat = static_cast<const GpuImagePlatformDataGL&>(srcGpuImage->GetPlatformData());
    const auto& bPlat = static_cast<const GpuBufferPlatformDataGL&>(dstGpuBuffer->GetPlatformData());
    if ((iPlat.type != GL_TEXTURE_CUBE_MAP) && (iPlat.type != GL_TEXTURE_2D)) {
        PLUGIN_LOG_E("Unsupported texture type in ImageToBufferCopy %x", iPlat.type);
        return;
    }
    device_.BindReadFrameBuffer(blitImageSourceFbo_);
    PLUGIN_ASSERT(bc.imageSubresource.layerCount == 1);
    GLenum type = GL_TEXTURE_2D;
    if (iPlat.type == GL_TEXTURE_CUBE_MAP) {
        type = getCubeMapTarget(iPlat.type, bc.imageSubresource.baseArrayLayer);
    }
    // glFramebufferTextureLayer for array textures....
    glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, type, static_cast<GLuint>(iPlat.image),
        static_cast<GLint>(bc.imageSubresource.mipLevel));
    const Math::UVec2 sPos { bc.imageOffset.width, bc.imageOffset.height };
    const Math::UVec2 sExt { bc.imageExtent.width, bc.imageExtent.height };
    device_.BindBuffer(GL_PIXEL_PACK_BUFFER, bPlat.buffer);
    glPixelStorei(GL_PACK_ROW_LENGTH, static_cast<GLint>(bc.bufferRowLength));
    glPixelStorei(GL_PACK_ALIGNMENT, 1);
    uintptr_t dstOffset = bc.bufferOffset + bPlat.currentByteOffset;
    glReadnPixels(static_cast<GLint>(sPos.x), static_cast<GLint>(sPos.y), static_cast<GLsizei>(sExt.x),
        static_cast<GLsizei>(sExt.y), iPlat.format, static_cast<GLenum>(iPlat.dataType),
        static_cast<GLsizei>(bPlat.alignedByteSize), reinterpret_cast<void*>(dstOffset));
    device_.BindBuffer(GL_PIXEL_PACK_BUFFER, 0);
    glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, type, 0, 0);
}

void RenderBackendGLES::RenderCommandCopyBufferImage(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::COPY_BUFFER_IMAGE);
    const auto& renderCmd = *static_cast<const struct RenderCommandCopyBufferImage*>(ref.rc);
    PLUGIN_ASSERT(inRenderpass_ == 0); // this command should never run during renderpass..
    if (renderCmd.copyType == RenderCommandCopyBufferImage::CopyType::BUFFER_TO_IMAGE) {
        BufferToImageCopy(renderCmd);
    } else if (renderCmd.copyType == RenderCommandCopyBufferImage::CopyType::IMAGE_TO_BUFFER) {
        ImageToBufferCopy(renderCmd);
    }
}

void RenderBackendGLES::RenderCommandCopyImage(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::COPY_IMAGE);
    const auto& renderCmd = *static_cast<const struct RenderCommandCopyImage*>(ref.rc);
    PLUGIN_ASSERT(inRenderpass_ == 0); // this command should never run during renderpass..
    const auto* srcGpuImage = gpuResourceMgr_.GetImage<GpuImageGLES>(renderCmd.srcHandle);
    const auto* dstGpuImage = gpuResourceMgr_.GetImage<GpuImageGLES>(renderCmd.dstHandle);
    if ((srcGpuImage == nullptr) || (dstGpuImage == nullptr)) {
        return;
    }
    const auto& srcDesc = srcGpuImage->GetDesc();
    const auto& dstDesc = dstGpuImage->GetDesc();
#if RENDER_VALIDATION_ENABLED
    ValidateCopyImage(renderCmd.imageCopy, srcDesc, dstDesc);
#endif
    const auto srcMipLevel =
        static_cast<GLint>(Math::min(renderCmd.imageCopy.srcSubresource.mipLevel, srcDesc.mipCount - 1));
    const auto dstMipLevel =
        static_cast<GLint>(Math::min(renderCmd.imageCopy.dstSubresource.mipLevel, dstDesc.mipCount - 1));

    auto sOffset = renderCmd.imageCopy.srcOffset;
    auto dOffset = renderCmd.imageCopy.dstOffset;
    auto size = renderCmd.imageCopy.extent;

    // clamp negative offsets to zero and adjust extent and other offset accordingly
    ClampOffset(sOffset, dOffset, size);
    ClampOffset(dOffset, sOffset, size);

    // clamp size to fit src and dst
    ClampSize(sOffset, srcDesc, size);
    ClampSize(dOffset, dstDesc, size);

    const auto& srcPlatData = srcGpuImage->GetPlatformData();
    const auto& dstPlatData = dstGpuImage->GetPlatformData();
    glCopyImageSubData(srcPlatData.image, srcPlatData.type, srcMipLevel, sOffset.x, sOffset.y, sOffset.z,
        dstPlatData.image, dstPlatData.type, dstMipLevel, dOffset.x, dOffset.y, dOffset.z,
        static_cast<GLsizei>(size.width), static_cast<GLsizei>(size.height), static_cast<GLsizei>(size.depth));
}

void RenderBackendGLES::RenderCommandBarrierPoint(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::BARRIER_POINT);
    const auto& renderCmd = *static_cast<const struct RenderCommandBarrierPoint*>(ref.rc);
    const auto& rbList = *managers_.rbList;
    // NOTE: proper flagging of barriers.
    if (const RenderBarrierList::BarrierPointBarriers* barrierPointBarriers =
            rbList.GetBarrierPointBarriers(renderCmd.barrierPointIndex);
        barrierPointBarriers) {
        const uint32_t barrierListCount = barrierPointBarriers->barrierListCount;
        const auto* nextBarrierList = barrierPointBarriers->firstBarrierList;
        GLbitfield barriers = 0;
        GLbitfield barriersByRegion = 0;
        for (uint32_t barrierListIndex = 0; barrierListIndex < barrierListCount; ++barrierListIndex) {
            if (nextBarrierList == nullptr) {
                // cannot be null, just a safety
                PLUGIN_ASSERT(false);
                return;
            }
            const auto& barrierListRef = *nextBarrierList;
            nextBarrierList = barrierListRef.nextBarrierPointBarrierList; // advance to next
            const uint32_t barrierCount = barrierListRef.count;
            // helper which covers barriers supported by Barrier and BarrierByRegion
            auto commonBarrierBits = [](AccessFlags accessFlags, RenderHandleType resourceType) -> GLbitfield {
                GLbitfield barriers = 0;
                if (accessFlags & CORE_ACCESS_UNIFORM_READ_BIT) {
                    barriers |= GL_UNIFORM_BARRIER_BIT;
                }
                if (accessFlags & CORE_ACCESS_SHADER_READ_BIT) {
                    // shader read covers UBO, SSBO, storage image etc. use resource type to limit the options.
                    if (resourceType == RenderHandleType::GPU_IMAGE) {
                        barriers |= GL_TEXTURE_FETCH_BARRIER_BIT | GL_SHADER_IMAGE_ACCESS_BARRIER_BIT;
                    } else if (resourceType == RenderHandleType::GPU_BUFFER) {
                        barriers |= GL_UNIFORM_BARRIER_BIT | GL_SHADER_STORAGE_BARRIER_BIT;
                    } else {
                        barriers |= GL_UNIFORM_BARRIER_BIT | GL_SHADER_STORAGE_BARRIER_BIT |
                                    GL_TEXTURE_FETCH_BARRIER_BIT | GL_SHADER_IMAGE_ACCESS_BARRIER_BIT;
                    }
                }
                if (accessFlags & CORE_ACCESS_SHADER_WRITE_BIT) {
                    if (resourceType == RenderHandleType::GPU_IMAGE) {
                        barriers |= GL_SHADER_IMAGE_ACCESS_BARRIER_BIT;
                    } else if (resourceType == RenderHandleType::GPU_BUFFER) {
                        barriers |= GL_SHADER_STORAGE_BARRIER_BIT;
                    } else {
                        barriers |= GL_SHADER_IMAGE_ACCESS_BARRIER_BIT | GL_SHADER_STORAGE_BARRIER_BIT;
                    }
                }
                if (accessFlags & (CORE_ACCESS_INPUT_ATTACHMENT_READ_BIT | CORE_ACCESS_COLOR_ATTACHMENT_READ_BIT |
                                      CORE_ACCESS_COLOR_ATTACHMENT_WRITE_BIT)) {
                    barriers |= GL_FRAMEBUFFER_BARRIER_BIT;
                }
                // GL_ATOMIC_COUNTER_BARRIER_BIT is not used at the moment
                return barriers;
            };
            for (uint32_t barrierIdx = 0; barrierIdx < barrierCount; ++barrierIdx) {
                const auto& barrier = barrierListRef.commandBarriers[barrierIdx];

                // check if written by previous shader as an attachment or storage/ image buffer
                if (barrier.src.accessFlags & (CORE_ACCESS_SHADER_WRITE_BIT | CORE_ACCESS_COLOR_ATTACHMENT_WRITE_BIT |
                                                  CORE_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT)) {
                    const auto resourceHandle = barrier.resourceHandle;
                    const auto handleType = RenderHandleUtil::GetHandleType(resourceHandle);

                    // barrier by region is between fragment shaders and supports a subset of barriers.
                    if ((barrier.src.pipelineStageFlags & CORE_PIPELINE_STAGE_FRAGMENT_SHADER_BIT) &&
                        (barrier.dst.pipelineStageFlags & CORE_PIPELINE_STAGE_FRAGMENT_SHADER_BIT)) {
                        barriersByRegion |= commonBarrierBits(barrier.dst.accessFlags, handleType);
                    } else {
                        // check the barriers shared with ByRegion
                        barriers |= commonBarrierBits(barrier.dst.accessFlags, handleType);

                        // the rest are invalid for ByRegion
                        if (barrier.dst.accessFlags & CORE_ACCESS_INDIRECT_COMMAND_READ_BIT) {
                            barriers |= GL_COMMAND_BARRIER_BIT;
                        }
                        if (barrier.dst.accessFlags & CORE_ACCESS_INDEX_READ_BIT) {
                            barriers |= GL_ELEMENT_ARRAY_BARRIER_BIT;
                        }
                        if (barrier.dst.accessFlags & CORE_ACCESS_VERTEX_ATTRIBUTE_READ_BIT) {
                            barriers |= GL_VERTEX_ATTRIB_ARRAY_BARRIER_BIT;
                        }
                        // which are the correct accessFlags?
                        // GL_PIXEL_BUFFER_BARRIER_BIT:
                        // - buffer objects via the GL_PIXEL_PACK_BUFFER and GL_PIXEL_UNPACK_BUFFER bindings (via
                        // glReadPixels, glTexSubImage1D, etc.)
                        // GL_TEXTURE_UPDATE_BARRIER_BIT:
                        // - texture via glTex(Sub)Image*, glCopyTex(Sub)Image*, glCompressedTex(Sub)Image*, and
                        // reads via glGetTexImage GL_BUFFER_UPDATE_BARRIER_BIT:
                        // - glBufferSubData, glCopyBufferSubData, or glGetBufferSubData, or to buffer object memory
                        // mapped
                        //  by glMapBuffer or glMapBufferRange
                        // These two are cover all memory access, CORE_ACCESS_MEMORY_READ_BIT,
                        // CORE_ACCESS_MEMORY_WRITE_BIT?
                        if (barrier.dst.accessFlags & (CORE_ACCESS_TRANSFER_READ_BIT | CORE_ACCESS_TRANSFER_WRITE_BIT |
                                                          CORE_ACCESS_HOST_READ_BIT | CORE_ACCESS_HOST_WRITE_BIT)) {
                            if (handleType == RenderHandleType::GPU_IMAGE) {
                                barriers |= GL_TEXTURE_UPDATE_BARRIER_BIT;
                            } else if (handleType == RenderHandleType::GPU_BUFFER) {
                                barriers |= GL_BUFFER_UPDATE_BARRIER_BIT | GL_PIXEL_BUFFER_BARRIER_BIT;
                            }
                        }
                        // GL_TRANSFORM_FEEDBACK_BARRIER_BIT is not used at the moment
                    }
                }
            }
        }
        if (barriers) {
            glMemoryBarrier(barriers);
        }
        if (barriersByRegion) {
            // only for fragment-fragment
            glMemoryBarrierByRegion(barriersByRegion);
        }
    }
}

Gles::Bind& RenderBackendGLES::SetupBind(const DescriptorSetLayoutBinding& binding, vector<Gles::Bind>& resources)
{
    PLUGIN_ASSERT(binding.binding < resources.size());
    auto& obj = resources[binding.binding];
    PLUGIN_ASSERT(obj.resources.size() == binding.descriptorCount);
    PLUGIN_ASSERT(obj.descriptorType == binding.descriptorType);
    return obj;
}

void RenderBackendGLES::BindSampler(const BindableSampler& res, Gles::Bind& obj, uint32_t index)
{
    const auto* gpuSampler = gpuResourceMgr_.GetSampler<GpuSamplerGLES>(res.handle);
    if (gpuSampler) {
        const auto& plat = gpuSampler->GetPlatformData();
        obj.resources[index].sampler.samplerId = plat.sampler;
    } else {
        obj.resources[index].sampler.samplerId = 0;
    }
}

void RenderBackendGLES::BindImage(
    const BindableImage& res, const GpuResourceState& resState, Gles::Bind& obj, uint32_t index)
{
    const AccessFlags accessFlags = resState.accessFlags;
    auto* gpuImage = gpuResourceMgr_.GetImage<GpuImageGLES>(res.handle);
    auto& ref = obj.resources[index];
    ref.image.image = gpuImage;
    const bool read = IS_BIT(accessFlags, CORE_ACCESS_SHADER_READ_BIT);
    const bool write = IS_BIT(accessFlags, CORE_ACCESS_SHADER_WRITE_BIT);
    if (read && write) {
        ref.image.mode = GL_READ_WRITE;
    } else if (read) {
        ref.image.mode = GL_READ_ONLY;
    } else if (write) {
        ref.image.mode = GL_WRITE_ONLY;
    } else {
        // no read and no write?
        ref.image.mode = GL_READ_WRITE;
    }
    ref.image.mipLevel = res.mip;
}

void RenderBackendGLES::BindImageSampler(
    const BindableImage& res, const GpuResourceState& resState, Gles::Bind& obj, uint32_t index)
{
    BindImage(res, resState, obj, index);
    BindSampler(BindableSampler { res.samplerHandle }, obj, index);
}

void RenderBackendGLES::BindBuffer(const BindableBuffer& res, Gles::Bind& obj, uint32_t dynamicOffset, uint32_t index)
{
    const auto* gpuBuffer = gpuResourceMgr_.GetBuffer<GpuBufferGLES>(res.handle);
    if (gpuBuffer) {
        const auto& plat = gpuBuffer->GetPlatformData();
        const uint32_t baseOffset = res.byteOffset;
        obj.resources[index].buffer.offset = baseOffset + plat.currentByteOffset + dynamicOffset;
        obj.resources[index].buffer.size = std::min(plat.bindMemoryByteSize - baseOffset, res.byteSize);
        obj.resources[index].buffer.bufferId = plat.buffer;
    } else {
        obj.resources[index].buffer.offset = 0;
        obj.resources[index].buffer.size = 0;
        obj.resources[index].buffer.bufferId = 0;
    }
}

void RenderBackendGLES::ProcessBindings(const struct RenderCommandBindDescriptorSets& renderCmd,
    const DescriptorSetLayoutBindingResources& data, uint32_t set)
{
    BindState& bind = boundObjects_[set];
    vector<Gles::Bind>& resources = bind.resources;
#if RENDER_HAS_GLES_BACKEND
    bind.oesBinds.clear();
#endif
    const auto& dynamicOffsets = renderCmd.descriptorSetDynamicOffsets[set];
    const auto& buffers = data.buffers;
    const auto& images = data.images;
    const auto& samplers = data.samplers;
    uint32_t currDynamic = 0U;
    for (const auto& res : data.bindings) {
        auto& obj = SetupBind(res.binding, resources);
#if RENDER_HAS_GLES_BACKEND
        bool hasOes = false;
#endif
        auto GetArrayOffset = [](const auto& data, const auto& res) {
            const RenderHandleType type = GetRenderHandleType(res.binding.descriptorType);
            if (type == RenderHandleType::GPU_BUFFER) {
                return data.buffers[res.resourceIndex].arrayOffset;
            } else if (type == RenderHandleType::GPU_IMAGE) {
                return data.images[res.resourceIndex].arrayOffset;
            } else if (type == RenderHandleType::GPU_SAMPLER) {
                return data.samplers[res.resourceIndex].arrayOffset;
            }
            return 0u;
        };
        const bool hasArrOffset = (res.binding.descriptorCount > 1);
        const uint32_t arrayOffset = hasArrOffset ? GetArrayOffset(data, res) : 0;
        for (uint8_t index = 0; index < res.binding.descriptorCount; index++) {
            const uint32_t resIdx = (index == 0) ? res.resourceIndex : (arrayOffset + index - 1);
            GpuImageGLES* image = nullptr;
            switch (res.binding.descriptorType) {
                case CORE_DESCRIPTOR_TYPE_SAMPLER: {
                    const auto& bRes = samplers[resIdx];
                    BindSampler(bRes.resource, obj, index);
                    break;
                }
                case CORE_DESCRIPTOR_TYPE_SAMPLED_IMAGE:
                case CORE_DESCRIPTOR_TYPE_STORAGE_IMAGE:
                case CORE_DESCRIPTOR_TYPE_INPUT_ATTACHMENT: {
                    const auto& bRes = images[resIdx];
                    BindImage(bRes.resource, bRes.state, obj, index);
                    image = obj.resources[index].image.image;
                    break;
                }
                case CORE_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER: {
                    const auto& bRes = images[resIdx];
                    BindImageSampler(bRes.resource, bRes.state, obj, index);
                    image = obj.resources[index].image.image;
                    break;
                }
                case CORE_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC:
                case CORE_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC: {
                    const auto& bRes = buffers[resIdx];
                    uint32_t dynamicOffset = 0;
                    if (currDynamic < dynamicOffsets.dynamicOffsetCount) {
                        dynamicOffset = dynamicOffsets.dynamicOffsets[currDynamic];
                        currDynamic++;
                    }
                    BindBuffer(bRes.resource, obj, dynamicOffset, index);
                    break;
                }
                case CORE_DESCRIPTOR_TYPE_UNIFORM_BUFFER:
                case CORE_DESCRIPTOR_TYPE_STORAGE_BUFFER: {
                    const auto& bRes = buffers[resIdx];
                    BindBuffer(bRes.resource, obj, 0, index);
                    break;
                }
                case CORE_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER:
                case CORE_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER:
                case CORE_DESCRIPTOR_TYPE_MAX_ENUM:
                default:
                    PLUGIN_ASSERT_MSG(false, "Unhandled descriptor type");
                    break;
            }
#if RENDER_HAS_GLES_BACKEND
            if ((image) && (image->GetPlatformData().type == GL_TEXTURE_EXTERNAL_OES)) {
                hasOes = true;
            }
#endif
        }
#if RENDER_HAS_GLES_BACKEND
        if (hasOes) {
            bind.oesBinds.push_back(OES_Bind { (uint8_t)set, (uint8_t)res.binding.binding });
        }
#endif
    }
}

void RenderBackendGLES::RenderCommandBindDescriptorSets(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::BIND_DESCRIPTOR_SETS);
    if (!boundComputePipeline_ && !boundGraphicsPipeline_) {
        return;
    }
    const auto& renderCmd = *static_cast<const struct RenderCommandBindDescriptorSets*>(ref.rc);
    PLUGIN_ASSERT_MSG(renderCmd.psoHandle == currentPsoHandle_, "psoHandle mismatch");

    const auto& aNcdsm = *managers_.descriptorSetMgr;
    for (uint32_t idx = renderCmd.firstSet; idx < renderCmd.firstSet + renderCmd.setCount; ++idx) {
        PLUGIN_ASSERT_MSG(idx < Gles::ResourceLimits::MAX_SETS, "Invalid descriptorset index");
        const auto descriptorSetHandle = renderCmd.descriptorSetHandles[idx];
        PLUGIN_ASSERT(RenderHandleUtil::IsValid(descriptorSetHandle));
        const auto& data = aNcdsm.GetCpuDescriptorSetData(descriptorSetHandle);
        boundObjects_[idx].dirty = true; // mark the set as "changed"
        ProcessBindings(renderCmd, data, idx);
        // (note, nothing actually gets bound yet.. just the bind cache is updated)
    }
}

void RenderBackendGLES::SetPushConstant(uint32_t program, const Gles::PushConstantReflection& pc, const void* data)
{
    const GLint location = static_cast<GLint>(pc.location);
    // the consts list has been filtered and cleared of unused uniforms.
    PLUGIN_ASSERT(location != Gles::INVALID_LOCATION);
    GLint count = Math::max(static_cast<GLint>(pc.arraySize), 1);
    switch (pc.type) {
        case GL_UNSIGNED_INT: {
            glProgramUniform1uiv(program, location, count, static_cast<const GLuint*>(data));
            break;
        }
        case GL_FLOAT: {
            glProgramUniform1fv(program, location, count, static_cast<const GLfloat*>(data));
            break;
        }
        case GL_FLOAT_VEC2: {
            glProgramUniform2fv(program, location, count, static_cast<const GLfloat*>(data));
            break;
        }
        case GL_FLOAT_VEC4: {
            glProgramUniform4fv(program, location, count, static_cast<const GLfloat*>(data));
            break;
        }
        case GL_FLOAT_MAT4: {
            glProgramUniformMatrix4fv(program, location, count, false, static_cast<const GLfloat*>(data));
            break;
        }
        case GL_UNSIGNED_INT_VEC4: {
            glProgramUniform4uiv(program, location, count, static_cast<const GLuint*>(data));
            break;
        }
        default:
            PLUGIN_ASSERT_MSG(false, "Unhandled pushconstant variable type");
    }
}

void RenderBackendGLES::SetPushConstants(uint32_t program, const array_view<Gles::PushConstantReflection>& consts)
{
    if (boundProgram_.setPushConstants) {
        boundProgram_.setPushConstants = false;
        const auto& renderCmd = boundProgram_.pushConstants;
        PLUGIN_ASSERT_MSG(renderCmd.psoHandle == currentPsoHandle_, "psoHandle mismatch");
        PLUGIN_ASSERT_MSG(renderCmd.pushConstant.byteSize > 0, "PushConstant byteSize is zero!");
        PLUGIN_ASSERT_MSG(renderCmd.data, "PushConstant data is nullptr!");
        if ((renderCmd.data == nullptr) || (renderCmd.pushConstant.byteSize == 0))
            return;
        // ASSERT: expecting data is valid
        // NOTE: handle rest of the types
        for (const auto& pc : consts) {
            const size_t offs = pc.offset;
            if ((offs + pc.size) > renderCmd.pushConstant.byteSize) {
                PLUGIN_LOG_E(
                    "pushConstant data invalid (data for %s is missing [offset:%zu size:%zu] byteSize of data:%u)",
                    pc.name.c_str(), pc.offset, pc.size, renderCmd.pushConstant.byteSize);
                continue;
            }
            /*
            NOTE: handle the strides....
            consts[i].array_stride;
            consts[i].matrix_stride; */
            SetPushConstant(program, pc, &renderCmd.data[offs]);
        }
    }
}

void RenderBackendGLES::RenderCommandPushConstant(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::PUSH_CONSTANT);
    if (!boundComputePipeline_ && !boundGraphicsPipeline_) {
        return;
    }
    const auto& renderCmd = *static_cast<const struct RenderCommandPushConstant*>(ref.rc);
    if (renderCmd.pushConstant.byteSize > 0) {
        PLUGIN_ASSERT(renderCmd.data);
        PLUGIN_ASSERT_MSG(renderCmd.psoHandle == currentPsoHandle_, "psoHandle mismatch");
        boundProgram_.setPushConstants = true;
        boundProgram_.pushConstants = renderCmd;
    }
}

void RenderBackendGLES::RenderCommandClearColorImage(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::CLEAR_COLOR_IMAGE);
#if RENDER_HAS_GLES_BACKEND
#if (RENDER_VALIDATION_ENABLED == 1)
    PLUGIN_LOG_ONCE_E("RenderBackendGLES::RenderCommandClearColorImage",
        "Render command clear color image not support with GLES. One should implement higher level path for "
        "clearing.");
#endif
#else
    const auto& renderCmd = *static_cast<const struct RenderCommandClearColorImage*>(ref.rc);

    const GpuImageGLES* imagePtr = gpuResourceMgr_.GetImage<GpuImageGLES>(renderCmd.handle);
    if (imagePtr) {
        const GpuImagePlatformDataGL& platImage = imagePtr->GetPlatformData();
        // NOTE: mip levels and array layers should be handled separately
        for (const auto& subresRef : renderCmd.ranges) {
            glClearTexImage(platImage.image,     // texture
                (int32_t)subresRef.baseMipLevel, // level
                platImage.format,                // format
                platImage.dataType,              // type
                &renderCmd.color);               // data
        }
    }
#endif
}

// dynamic states
void RenderBackendGLES::RenderCommandDynamicStateViewport(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::DYNAMIC_STATE_VIEWPORT);
    const auto& renderCmd = *static_cast<const struct RenderCommandDynamicStateViewport*>(ref.rc);
    const ViewportDesc& vd = renderCmd.viewportDesc;
    SetViewport(renderArea_, vd);
}

void RenderBackendGLES::RenderCommandDynamicStateScissor(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::DYNAMIC_STATE_SCISSOR);
    const auto& renderCmd = *static_cast<const struct RenderCommandDynamicStateScissor*>(ref.rc);
    const ScissorDesc& sd = renderCmd.scissorDesc;
    SetScissor(renderArea_, sd);
}

void RenderBackendGLES::RenderCommandDynamicStateLineWidth(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::DYNAMIC_STATE_LINE_WIDTH);
    const auto& renderCmd = *static_cast<const struct RenderCommandDynamicStateLineWidth*>(ref.rc);
    if (renderCmd.lineWidth != cacheState_.rasterizationState.lineWidth) {
        cacheState_.rasterizationState.lineWidth = renderCmd.lineWidth;
        glLineWidth(renderCmd.lineWidth);
    }
}

void RenderBackendGLES::RenderCommandDynamicStateDepthBias(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::DYNAMIC_STATE_DEPTH_BIAS);
    PLUGIN_ASSERT_MSG(false, "RenderCommandDynamicStateDepthBias not implemented");
}

void RenderBackendGLES::RenderCommandDynamicStateBlendConstants(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::DYNAMIC_STATE_BLEND_CONSTANTS);
    PLUGIN_ASSERT_MSG(false, "RenderCommandDynamicStateBlendConstants not implemented");
}

void RenderBackendGLES::RenderCommandDynamicStateDepthBounds(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::DYNAMIC_STATE_DEPTH_BOUNDS);
    PLUGIN_ASSERT_MSG(false, "RenderCommandDynamicStateDepthBounds not implemented");
}

void RenderBackendGLES::SetStencilState(const uint32_t frontFlags, const GraphicsState::StencilOpState& front,
    const uint32_t backFlags, const GraphicsState::StencilOpState& back)
{
    auto& cFront = cacheState_.depthStencilState.frontStencilOpState;
    auto& cBack = cacheState_.depthStencilState.backStencilOpState;
    const uint32_t FUNCMASK =
        (StencilSetFlags::SETCOMPAREOP | StencilSetFlags::SETCOMPAREMASK | StencilSetFlags::SETREFERENCE);
    if (frontFlags & StencilSetFlags::SETWRITEMASK) {
        cFront.writeMask = front.writeMask;
        glStencilMaskSeparate(GL_FRONT, cFront.writeMask);
    }
    if (frontFlags & FUNCMASK) {
        SetStencilCompareOp(cFront, front);
        glStencilFuncSeparate(
            GL_FRONT, GetCompareOp(cFront.compareOp), static_cast<GLint>(cFront.reference), cFront.compareMask);
    }
    if (frontFlags & StencilSetFlags::SETOP) {
        SetStencilOp(cFront, front);
        glStencilOpSeparate(
            GL_FRONT, GetStencilOp(cFront.failOp), GetStencilOp(cFront.depthFailOp), GetStencilOp(cFront.passOp));
    }
    if (backFlags & StencilSetFlags::SETWRITEMASK) {
        cBack.writeMask = back.writeMask;
        glStencilMaskSeparate(GL_BACK, cBack.writeMask);
    }
    if (backFlags & FUNCMASK) {
        SetStencilCompareOp(cBack, back);
        glStencilFuncSeparate(
            GL_BACK, GetCompareOp(cBack.compareOp), static_cast<GLint>(cBack.reference), cBack.compareMask);
    }
    if (backFlags & StencilSetFlags::SETOP) {
        SetStencilOp(cBack, back);
        glStencilOpSeparate(
            GL_FRONT, GetStencilOp(cBack.failOp), GetStencilOp(cBack.depthFailOp), GetStencilOp(cBack.passOp));
    }
}

void RenderBackendGLES::RenderCommandDynamicStateStencil(const RenderCommandWithType& ref)
{
    PLUGIN_ASSERT(ref.type == RenderCommandType::DYNAMIC_STATE_STENCIL);
    const auto& renderCmd = *static_cast<const struct RenderCommandDynamicStateStencil*>(ref.rc);
    auto& cFront = cacheState_.depthStencilState.frontStencilOpState;
    auto& cBack = cacheState_.depthStencilState.backStencilOpState;
    uint32_t setFront = 0;
    uint32_t setBack = 0;
    if (renderCmd.faceMask & StencilFaceFlagBits::CORE_STENCIL_FACE_FRONT_BIT) {
        if (renderCmd.dynamicState == StencilDynamicState::COMPARE_MASK) {
            if (renderCmd.mask != cFront.compareMask) {
                cFront.compareMask = renderCmd.mask;
                setFront |= StencilSetFlags::SETCOMPAREMASK;
            }
        } else if (renderCmd.dynamicState == StencilDynamicState::WRITE_MASK) {
            if (renderCmd.mask != cFront.writeMask) {
                cFront.writeMask = renderCmd.mask;
                setFront |= StencilSetFlags::SETWRITEMASK;
            }
        } else if (renderCmd.dynamicState == StencilDynamicState::REFERENCE) {
            if (renderCmd.mask != cFront.reference) {
                cFront.reference = renderCmd.mask;
                setFront |= StencilSetFlags::SETREFERENCE;
            }
        }
    }
    if (renderCmd.faceMask & StencilFaceFlagBits::CORE_STENCIL_FACE_BACK_BIT) {
        if (renderCmd.dynamicState == StencilDynamicState::COMPARE_MASK) {
            if (renderCmd.mask != cBack.compareMask) {
                cBack.compareMask = renderCmd.mask;
                setBack |= StencilSetFlags::SETCOMPAREMASK;
            }
        } else if (renderCmd.dynamicState == StencilDynamicState::WRITE_MASK) {
            if (renderCmd.mask != cBack.writeMask) {
                cBack.writeMask = renderCmd.mask;
                setBack |= StencilSetFlags::SETWRITEMASK;
            }
        } else if (renderCmd.dynamicState == StencilDynamicState::REFERENCE) {
            if (renderCmd.mask != cBack.reference) {
                cBack.reference = renderCmd.mask;
                setBack |= StencilSetFlags::SETREFERENCE;
            }
        }
    }
    SetStencilState(setFront, cFront, setBack, cBack);
}

void RenderBackendGLES::RenderCommandFragmentShadingRate(const RenderCommandWithType& renderCmd)
{
#if (RENDER_VALIDATION_ENABLED == 1)
    PLUGIN_LOG_ONCE_I("gles_RenderCommandFragmentShadingRate",
        "RENDER_VALIDATION: Fragment shading rate not available with GL(ES) backend.");
#endif
}

void RenderBackendGLES::RenderCommandExecuteBackendFramePosition(const RenderCommandWithType& renderCmd)
{
    PLUGIN_ASSERT_MSG(false, "RenderCommandExecuteBackendFramePosition not implemented");
}

void RenderBackendGLES::RenderCommandWriteTimestamp(const RenderCommandWithType& renderCmd)
{
    PLUGIN_ASSERT_MSG(false, "RenderCommandWriteTimestamp not implemented");
}

void RenderBackendGLES::BindVertexInputs(
    const VertexInputDeclarationData& decldata, const array_view<const int32_t>& vertexInputs)
{
    // update bindings for the VAO.
    // process with attribute descriptions to only bind the needed vertex buffers
    // NOTE: that there are or might be extran bindings in the decldata.bindingDescriptions,
    // but we only bind the ones needed for the shader
    const uint32_t minBinding = Math::min(vertexAttribBinds_, decldata.attributeDescriptionCount);
    for (uint32_t i = 0; i < minBinding; ++i) {
        const auto& attributeRef = decldata.attributeDescriptions[i];
        const uint32_t location = attributeRef.location;
        const uint32_t binding = attributeRef.binding;
        // NOTE: we need to bind all the buffers to the correct bindings.
        // shader optimized check (vertexInputs, some locations are not in use)
        if ((location != ~0u) && (binding != ~0u) && (vertexInputs[location] != Gles::INVALID_LOCATION)) {
            const auto& slot = vertexAttribBindSlots_[binding];
            const auto& bindingRef = decldata.bindingDescriptions[binding];
            PLUGIN_ASSERT(bindingRef.binding == binding);
            // buffer bound to slot, and it's used by the shader.
            device_.BindVertexBuffer(binding, slot.id, slot.offset, static_cast<intptr_t>(bindingRef.stride));
            /*
            core/vulkan
            bindingRef.vertexInputRate =  CORE_VERTEX_INPUT_RATE_VERTEX (0)  attribute index advances per vertex
            bindingRef.vertexInputRate =  CORE_VERTEX_INPUT_RATE_INSTANCE (1)  attribute index advances per instance

            gl/gles
            If divisor is  0, the attributes using the buffer bound to bindingindex advance once per vertex.
            If divisor is >0, the attributes advance once per divisor instances of the set(s) of vertices being
            rendered.

            so we can directly pass the inputRate as VertexBindingDivisor. (ie. advance once per instance)
            ie. enum happens to match and can simply cast.
            */
            static_assert(CORE_VERTEX_INPUT_RATE_VERTEX == 0 && CORE_VERTEX_INPUT_RATE_INSTANCE == 1);
            device_.VertexBindingDivisor(binding, static_cast<uint32_t>(bindingRef.vertexInputRate));
        }
    }
}

void RenderBackendGLES::BindResources()
{
#if RENDER_HAS_GLES_BACKEND
    // scan all sets here to see if any of the sets has oes.
    // we don't actually need to rebuild this info every time.
    // should "emulate" the gpu descriptor sets better. (and store this information along with the other bind cache
    // data there)
    oesBinds_.clear();
    for (const auto& state : boundObjects_) {
        const auto& oes = state.oesBinds;
        if (!oes.empty()) {
            oesBinds_.insert(oesBinds_.end(), oes.begin(), oes.end());
        }
    }
#endif
    const array_view<Binder>* resourceList = nullptr;
    const array_view<Gles::PushConstantReflection>* pushConstants = nullptr;
    int32_t flipLocation = Gles::INVALID_LOCATION;
    uint32_t program = 0;
    // Push constants and "fliplocation" uniform (ie. uniform state) should be only updated if changed...
    if (currentFrameBuffer_) { // mCurrentFrameBuffer is only set if graphics pipeline is bound..
        PLUGIN_ASSERT(boundComputePipeline_ == nullptr);
        PLUGIN_ASSERT(boundGraphicsPipeline_);
        if (!boundGraphicsPipeline_) {
            return;
        }
        array_view<const int32_t> vertexInputs;
        const auto& pipelineData =
            static_cast<const PipelineStateObjectPlatformDataGL&>(boundGraphicsPipeline_->GetPlatformData());
        const GpuShaderProgramGLES* shader = pipelineData.graphicsShader;
#if RENDER_HAS_GLES_BACKEND
        if (!oesBinds_.empty()) {
            // okay, oes vector contains the set/bind to which an OES texture is bounds
            // ask for a compatible program from the boundGraphicsPipeline_
            shader = boundGraphicsPipeline_->GetOESProgram(oesBinds_);
        }
#endif
        const auto& sd = static_cast<const GpuShaderProgramPlatformDataGL&>(shader->GetPlatformData());
        program = sd.program;
        vertexInputs = { sd.inputs, countof(sd.inputs) };
        FlushViewportScissors();
        if (!scissorEnabled_) {
            scissorEnabled_ = true;
            glEnable(GL_SCISSOR_TEST); // Always enabled
        }
#if (RENDER_PERF_ENABLED == 1)
        if (device_.BoundProgram() != program) {
            ++perfCounters_.bindProgram;
        }
#endif
        device_.UseProgram(program);
        device_.BindVertexArray(pipelineData.vao);
        BindVertexInputs(pipelineData.vertexInputDeclaration, vertexInputs);
        device_.BindElementBuffer(boundIndexBuffer_.id);
        resourceList = &sd.resourceList;
        flipLocation = sd.flipLocation;
        pushConstants = &sd.pushConstants;
    } else {
        PLUGIN_ASSERT(boundGraphicsPipeline_ == nullptr);
        PLUGIN_ASSERT(boundComputePipeline_);
        if (!boundComputePipeline_) {
            return;
        }
        const auto& pipelineData =
            static_cast<const PipelineStateObjectPlatformDataGL&>(boundComputePipeline_->GetPlatformData());
        if (pipelineData.computeShader) {
            const auto& sd =
                static_cast<const GpuComputeProgramPlatformDataGL&>(pipelineData.computeShader->GetPlatformData());
            program = sd.program;
#if (RENDER_PERF_ENABLED == 1)
            if (device_.BoundProgram() != program) {
                ++perfCounters_.bindProgram;
            }
#endif
            device_.UseProgram(program);
            resourceList = &sd.resourceList;
            flipLocation = sd.flipLocation;
            pushConstants = &sd.pushConstants;
        }
    }

    SetPushConstants(program, *pushConstants);
    if (flipLocation != Gles::INVALID_LOCATION) {
        const float flip = (renderingToDefaultFbo_) ? (-1.f) : (1.f);
        glProgramUniform1fv(program, flipLocation, 1, &flip);
    }

    for (const auto& r : *resourceList) {
        PLUGIN_ASSERT(r.set < PipelineLayoutConstants::MAX_DESCRIPTOR_SET_COUNT);
        if (r.bind >= static_cast<uint32_t>(boundObjects_[r.set].resources.size())) {
            continue;
        }
        const auto& res = boundObjects_[r.set].resources[r.bind];
        PLUGIN_ASSERT(res.resources.size() == r.id.size());
        auto resType = res.descriptorType;
        if (resType == CORE_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC) {
            resType = CORE_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
        } else if (resType == CORE_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC) {
            resType = CORE_DESCRIPTOR_TYPE_STORAGE_BUFFER;
        }

        // a few helpers for updating perf counters and binding the sampler/texture/buffer
        auto bindSampler = [this](uint32_t textureUnit, uint32_t samplerId) {
#if (RENDER_PERF_ENABLED == 1)
            if (device_.BoundSampler(textureUnit) != samplerId) {
                ++perfCounters_.bindSampler;
            }
#endif
            device_.BindSampler(textureUnit, samplerId);
        };
        auto bindTexture = [this](uint32_t textureUnit, const GpuImagePlatformDataGL& dplat) {
#if (RENDER_PERF_ENABLED == 1)
            if (device_.BoundTexture(textureUnit, dplat.type) != dplat.image) {
                ++perfCounters_.bindTexture;
            }
#endif
            device_.BindTexture(textureUnit, dplat.type, dplat.image);
        };
        auto bindTextureImage = [this](uint32_t textureUnit, const Gles::Bind::ImageType& image,
                                    const GpuImagePlatformDataGL& dplat) {
            uint32_t level = (image.mipLevel != PipelineStateConstants::GPU_IMAGE_ALL_MIP_LEVELS) ? image.mipLevel : 0U;
            device_.BindImageTexture(textureUnit, dplat.image, level, false, 0, image.mode, dplat.internalFormat);
        };
        auto bindBuffer = [this](uint32_t target, uint32_t binding, const Gles::Bind::BufferType& buffer) {
#if (RENDER_PERF_ENABLED == 1)
            if (device_.BoundBuffer(target) != buffer.bufferId) {
                ++perfCounters_.bindBuffer;
            }
#endif
            device_.BindBufferRange(target, binding, buffer.bufferId, buffer.offset, buffer.size);
        };
        auto setMipLevel = [](const uint32_t type, const uint32_t mipLevel) {
            // either force the defined mip level or use defaults.
            glTexParameteri(type, GL_TEXTURE_BASE_LEVEL,
                static_cast<GLint>((mipLevel != PipelineStateConstants::GPU_IMAGE_ALL_MIP_LEVELS) ? mipLevel : 0U));
            glTexParameteri(type, GL_TEXTURE_MAX_LEVEL,
                static_cast<GLint>((mipLevel != PipelineStateConstants::GPU_IMAGE_ALL_MIP_LEVELS) ? mipLevel : 1000U));
        };

#if (RENDER_VALIDATION_ENABLED == 1)
        if (resType != r.type) {
            PLUGIN_LOG_ONCE_E(
                "backend_desc_type_mismatch_gles", "RENDER_VALIDATION: shader / pipeline descriptor type mismatch");
        }
#endif

        for (uint32_t index = 0; index < res.resources.size(); index++) {
            const auto& obj = res.resources[index];
            for (const auto& id : r.id[index]) {
                const auto binding = index + id;
                if (resType == CORE_DESCRIPTOR_TYPE_SAMPLER) {
                    bindSampler(binding, obj.sampler.samplerId);
                } else if ((resType == CORE_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER) ||
                           (resType == CORE_DESCRIPTOR_TYPE_SAMPLED_IMAGE) ||
                           (resType == CORE_DESCRIPTOR_TYPE_INPUT_ATTACHMENT)) {
                    if (resType == CORE_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER) {
                        bindSampler(binding, obj.sampler.samplerId);
                    } else if (resType == CORE_DESCRIPTOR_TYPE_INPUT_ATTACHMENT) {
                        bindSampler(binding, 0U);
                    }
                    if (obj.image.image) {
                        auto& dplat = obj.image.image->GetPlatformData();
                        bindTexture(binding, dplat);

                        // NOTE: the last setting is active, can not have different miplevels bound from single
                        // resource.
                        // Check and update (if needed) the forced miplevel.
                        if (dplat.mipLevel != obj.image.mipLevel) {
                            // NOTE: we are actually modifying the texture object bound above
                            const_cast<GpuImagePlatformDataGL&>(dplat).mipLevel = obj.image.mipLevel;
                            setMipLevel(dplat.type, dplat.mipLevel);
                        }
                    }
                } else if (resType == CORE_DESCRIPTOR_TYPE_STORAGE_IMAGE) {
                    if (obj.image.image) {
                        auto& dplat = obj.image.image->GetPlatformData();
                        bindTextureImage(binding, obj.image, dplat);
                    }
                } else if (resType == CORE_DESCRIPTOR_TYPE_UNIFORM_BUFFER) {
                    bindBuffer(GL_UNIFORM_BUFFER, binding, obj.buffer);
                } else if (resType == CORE_DESCRIPTOR_TYPE_STORAGE_BUFFER) {
                    bindBuffer(GL_SHADER_STORAGE_BUFFER, binding, obj.buffer);
                }
            }
        }
    }
    // mark all bound.
    for (auto& b : boundObjects_) {
        b.dirty = false;
    }
}

#if (RENDER_PERF_ENABLED == 1)
void RenderBackendGLES::StartFrameTimers(const RenderCommandFrameData& renderCommandFrameData)
{
    for (const auto& renderCommandContext : renderCommandFrameData.renderCommandContexts) {
        const string_view& debugName = renderCommandContext.debugName;
        if (timers_.count(debugName) == 0) { // new timers
#if (RENDER_GPU_TIMESTAMP_QUERIES_ENABLED == 1)
            PerfDataSet& perfDataSet = timers_[debugName];
            constexpr GpuQueryDesc desc { QueryType::CORE_QUERY_TYPE_TIMESTAMP, 0 };
            perfDataSet.gpuHandle = gpuQueryMgr_->Create(debugName, CreateGpuQueryGLES(device_, desc));
            perfDataSet.counter = 0u;
#else
            timers_.insert({ debugName, {} });
#endif
        }
    }
}

void RenderBackendGLES::EndFrameTimers()
{
    int64_t fullGpuTime = 0;
#if (RENDER_GPU_TIMESTAMP_QUERIES_ENABLED == 1)
    // already in micros
    fullGpuTime = fullGpuCounter_;
    fullGpuCounter_ = 0;
#endif
    if (CORE_NS::IPerformanceDataManagerFactory* globalPerfData =
            CORE_NS::GetInstance<CORE_NS ::IPerformanceDataManagerFactory>(CORE_NS::UID_PERFORMANCE_FACTORY);
        globalPerfData) {
        CORE_NS::IPerformanceDataManager* perfData = globalPerfData->Get("Renderer");
        perfData->UpdateData("RenderBackend", "Full_Cpu", commonCpuTimers_.full.GetMicroseconds());
        perfData->UpdateData("RenderBackend", "Acquire_Cpu", commonCpuTimers_.acquire.GetMicroseconds());
        perfData->UpdateData("RenderBackend", "Execute_Cpu", commonCpuTimers_.execute.GetMicroseconds());
        perfData->UpdateData("RenderBackend", "Submit_Cpu", commonCpuTimers_.submit.GetMicroseconds());
        perfData->UpdateData("RenderBackend", "Present_Cpu", commonCpuTimers_.present.GetMicroseconds());
        perfData->UpdateData("RenderBackend", "Full_Gpu", fullGpuTime);
    }
}

void RenderBackendGLES::CopyPerfTimeStamp(const string_view name, PerfDataSet& perfDataSet)
{
#if (RENDER_GPU_TIMESTAMP_QUERIES_ENABLED == 1)
    int64_t gpuMicroSeconds = 0;
    if (validGpuQueries_) {
        GpuQuery* gpuQuery = gpuQueryMgr_->Get(perfDataSet.gpuHandle);
        PLUGIN_ASSERT(gpuQuery);

        gpuQuery->NextQueryIndex();

        const auto& platData = static_cast<const GpuQueryPlatformDataGLES&>(gpuQuery->GetPlatformData());
        PLUGIN_ASSERT(platData.queryObject);

        GLint disjointOccurred = 0;
#ifdef GL_GPU_DISJOINT_EXT
        // Clear disjoint error
        glGetIntegerv(GL_GPU_DISJOINT_EXT, &disjointOccurred);
#endif
        if (!disjointOccurred && (++perfDataSet.counter) > device_.GetCommandBufferingCount()) {
            GLuint64 gpuNanoSeconds = 0U;
#ifdef GL_GPU_DISJOINT_EXT
            glGetQueryObjectui64vEXT(platData.queryObject, GL_QUERY_RESULT, &gpuNanoSeconds);
#else
            glGetQueryObjectui64v(platData.queryObject, GL_QUERY_RESULT, &gpuNanoSeconds);
#endif
            static uint64_t NANOSECONDS_TO_MICROSECONDS = 1000;
            gpuMicroSeconds = static_cast<int64_t>(gpuNanoSeconds / NANOSECONDS_TO_MICROSECONDS);
            if (gpuMicroSeconds > UINT32_MAX) {
                gpuMicroSeconds = 0;
            }
            fullGpuCounter_ += gpuMicroSeconds;
        } else if (disjointOccurred) {
            PLUGIN_LOG_V("GL_GPU_DISJOINT_EXT disjoint occurred.");
        }
    }
#endif
    const int64_t cpuMicroSeconds = perfDataSet.cpuTimer.GetMicroseconds();

    if (CORE_NS::IPerformanceDataManagerFactory* globalPerfData =
            CORE_NS::GetInstance<CORE_NS::IPerformanceDataManagerFactory>(CORE_NS::UID_PERFORMANCE_FACTORY);
        globalPerfData) {
        CORE_NS::IPerformanceDataManager* perfData = globalPerfData->Get("RenderNode");

        perfData->UpdateData(name, "Backend_Cpu", cpuMicroSeconds);
#if (RENDER_GPU_TIMESTAMP_QUERIES_ENABLED == 1)
        perfData->UpdateData(name, "Backend_Gpu", gpuMicroSeconds);
#endif
        perfData->UpdateData(name, "Backend_Count_Triangle", perfCounters_.triangleCount);
        perfData->UpdateData(name, "Backend_Count_InstanceCount", perfCounters_.instanceCount);
        perfData->UpdateData(name, "Backend_Count_Draw", perfCounters_.drawCount);
        perfData->UpdateData(name, "Backend_Count_DrawIndirect", perfCounters_.drawIndirectCount);
        perfData->UpdateData(name, "Backend_Count_Dispatch", perfCounters_.dispatchCount);
        perfData->UpdateData(name, "Backend_Count_DispatchIndirect", perfCounters_.dispatchIndirectCount);
        perfData->UpdateData(name, "Backend_Count_RenderPass", perfCounters_.renderPassCount);
        perfData->UpdateData(name, "Backend_Count_BindProgram", perfCounters_.bindProgram);
        perfData->UpdateData(name, "Backend_Count_BindSample", perfCounters_.bindSampler);
        perfData->UpdateData(name, "Backend_Count_BindTexture", perfCounters_.bindTexture);
        perfData->UpdateData(name, "Backend_Count_BindBuffer", perfCounters_.bindBuffer);
    }
}
#endif

void RenderBackendGLES::PrimeDepthStencilState(const GraphicsState& graphicsState)
{
    auto& cDepth = cacheState_.depthStencilState;
    cDepth = graphicsState.depthStencilState;
    // CORE_DYNAMIC_STATE_DEPTH_BOUNDS NOT SUPPORTED ON GLES. (and not implemented on GL either)
    SetState(GL_DEPTH_TEST, cDepth.enableDepthTest);
    SetState(GL_STENCIL_TEST, cDepth.enableStencilTest);
    glDepthFunc(GetCompareOp(cDepth.depthCompareOp));
    glDepthMask((cDepth.enableDepthWrite ? static_cast<GLboolean>(GL_TRUE) : static_cast<GLboolean>(GL_FALSE)));
    const uint32_t updateAllFlags =
        (StencilSetFlags::SETOP | StencilSetFlags::SETCOMPAREMASK | StencilSetFlags::SETCOMPAREOP |
            StencilSetFlags::SETREFERENCE | StencilSetFlags::SETWRITEMASK);
    SetStencilState(updateAllFlags, cDepth.frontStencilOpState, updateAllFlags, cDepth.backStencilOpState);
}

void RenderBackendGLES::PrimeBlendState(const GraphicsState& graphicsState)
{
    auto& cBlend = cacheState_.colorBlendState;
    cBlend = graphicsState.colorBlendState;
    glBlendColor(cBlend.colorBlendConstants[Gles::RED_INDEX], cBlend.colorBlendConstants[Gles::GREEN_INDEX],
        cBlend.colorBlendConstants[Gles::BLUE_INDEX], cBlend.colorBlendConstants[Gles::ALPHA_INDEX]);
    GLuint maxColorAttachments;
    glGetIntegerv(GL_MAX_COLOR_ATTACHMENTS, (GLint*)&maxColorAttachments);
    maxColorAttachments = BASE_NS::Math::min(PipelineStateConstants::MAX_COLOR_ATTACHMENT_COUNT, maxColorAttachments);
    for (GLuint i = 0; i < maxColorAttachments; i++) {
        const auto& cBlendState = cBlend.colorAttachments[i];
        glColorMaski(i, IS_BIT_GL(cBlendState.colorWriteMask, CORE_COLOR_COMPONENT_R_BIT),
            IS_BIT_GL(cBlendState.colorWriteMask, CORE_COLOR_COMPONENT_G_BIT),
            IS_BIT_GL(cBlendState.colorWriteMask, CORE_COLOR_COMPONENT_B_BIT),
            IS_BIT_GL(cBlendState.colorWriteMask, CORE_COLOR_COMPONENT_A_BIT));
        if (cBlendState.enableBlend) {
            glEnablei(GL_BLEND, i);
        } else {
            glDisablei(GL_BLEND, i);
        }
        glBlendFuncSeparatei(i, GetBlendFactor(cBlendState.srcColorBlendFactor),
            GetBlendFactor(cBlendState.dstColorBlendFactor), GetBlendFactor(cBlendState.srcAlphaBlendFactor),
            GetBlendFactor(cBlendState.dstAlphaBlendFactor));
        glBlendEquationSeparatei(i, GetBlendOp(cBlendState.colorBlendOp), GetBlendOp(cBlendState.alphaBlendOp));
    }
    // logicops are unsupported on GLES
}

void RenderBackendGLES::PrimeCache(const GraphicsState& graphicsState) // Forces the graphics state..
{
    if (cachePrimed_) {
        return;
    }
    cachePrimed_ = true;
    /// GRAPHICSSTATE     inputAssembly
    const auto& ia = graphicsState.inputAssembly;
    auto& cia = cacheState_.inputAssembly;
    cia.enablePrimitiveRestart = ia.enablePrimitiveRestart;
    SetState(GL_PRIMITIVE_RESTART_FIXED_INDEX, ia.enablePrimitiveRestart);
    topology_ = ia.primitiveTopology;
    /// GRAPHICSSTATE     rasterizationState
    const auto& rs = graphicsState.rasterizationState;
    auto& crs = cacheState_.rasterizationState;
    // save, since we need to hack for non fill modes etc ! (possibly need shader help for lines...)
    polygonMode_ = rs.polygonMode;
    // GL_DEPTH_CLAMP,rs.enableDepthClamp NOT SUPPORTED    CHECK GLES 3.2
    crs.enableRasterizerDiscard = rs.enableRasterizerDiscard;
    SetState(GL_RASTERIZER_DISCARD, rs.enableRasterizerDiscard);
    crs.enableDepthBias = rs.enableDepthBias;
    SetState(GL_POLYGON_OFFSET_FILL, rs.enableDepthBias);
    crs.depthBiasConstantFactor = rs.depthBiasConstantFactor;
    crs.depthBiasSlopeFactor = rs.depthBiasSlopeFactor;
    glPolygonOffset(rs.depthBiasSlopeFactor, rs.depthBiasConstantFactor);
    // depthBiasClamp NOT SUPPORTED! CHECK GLES 3.2
    // If cull mode Flags change...
    crs.cullModeFlags = rs.cullModeFlags;
    SetCullMode(crs);
    crs.frontFace = rs.frontFace;
    SetFrontFace(crs);
    crs.lineWidth = rs.lineWidth;
    glLineWidth(rs.lineWidth);
    PrimeDepthStencilState(graphicsState);
    PrimeBlendState(graphicsState);
}

void RenderBackendGLES::UpdateDepthState(const GraphicsState& graphicsState)
{
    const auto& depth = graphicsState.depthStencilState;
    auto& cDepth = cacheState_.depthStencilState;
    if (depth.enableDepthTest != cDepth.enableDepthTest) {
        cDepth.enableDepthTest = depth.enableDepthTest;
        SetState(GL_DEPTH_TEST, depth.enableDepthTest);
    }
    if (depth.depthCompareOp != cDepth.depthCompareOp) {
        cDepth.depthCompareOp = depth.depthCompareOp;
        glDepthFunc(GetCompareOp(depth.depthCompareOp));
    }
    if (depth.enableDepthWrite != cDepth.enableDepthWrite) {
        cDepth.enableDepthWrite = depth.enableDepthWrite;
        glDepthMask((depth.enableDepthWrite == GL_TRUE));
    }
    if (!IS_BIT(dynamicStateFlags_, CORE_DYNAMIC_STATE_DEPTH_BOUNDS)) {
        // CORE_DYNAMIC_STATE_DEPTH_BOUNDS not supported on GLES.
    }
}

void RenderBackendGLES::UpdateStencilState(const GraphicsState& graphicsState)
{
    const auto& depth = graphicsState.depthStencilState;
    auto& cDepth = cacheState_.depthStencilState;
    if (depth.enableStencilTest != cDepth.enableStencilTest) {
        cDepth.enableStencilTest = depth.enableStencilTest;
        SetState(GL_STENCIL_TEST, depth.enableStencilTest);
    }
    uint32_t setFront = 0;
    uint32_t setBack = 0;
    if (!IS_BIT(dynamicStateFlags_, CORE_DYNAMIC_STATE_STENCIL_REFERENCE)) {
        if (cDepth.frontStencilOpState.reference != depth.frontStencilOpState.reference) {
            setFront |= StencilSetFlags::SETREFERENCE;
        }
        if (cDepth.backStencilOpState.reference != depth.backStencilOpState.reference) {
            setBack |= StencilSetFlags::SETREFERENCE;
        }
    }
    if (!IS_BIT(dynamicStateFlags_, CORE_DYNAMIC_STATE_STENCIL_COMPARE_MASK)) {
        if (cDepth.frontStencilOpState.compareMask != depth.frontStencilOpState.compareMask) {
            setFront |= StencilSetFlags::SETCOMPAREMASK;
        }
        if (cDepth.backStencilOpState.compareMask != depth.backStencilOpState.compareMask) {
            setBack |= StencilSetFlags::SETCOMPAREMASK;
        }
    }
    if (!IS_BIT(dynamicStateFlags_, CORE_DYNAMIC_STATE_STENCIL_WRITE_MASK)) {
        if (cDepth.frontStencilOpState.writeMask != depth.frontStencilOpState.writeMask) {
            setFront |= StencilSetFlags::SETWRITEMASK;
        }
        if (cDepth.backStencilOpState.writeMask != depth.backStencilOpState.writeMask) {
            setBack |= StencilSetFlags::SETWRITEMASK;
        }
    }
    if (cDepth.frontStencilOpState.compareOp != depth.frontStencilOpState.compareOp) {
        setFront |= StencilSetFlags::SETCOMPAREOP;
    }
    if (cDepth.backStencilOpState.compareOp != depth.backStencilOpState.compareOp) {
        setBack |= StencilSetFlags::SETCOMPAREOP;
    }
    if (!CompareStencilOp(cDepth.frontStencilOpState, depth.frontStencilOpState)) {
        setFront |= StencilSetFlags::SETOP;
    }
    if (!CompareStencilOp(cDepth.backStencilOpState, depth.backStencilOpState)) {
        setBack |= StencilSetFlags::SETOP;
    }
    SetStencilState(setFront, depth.frontStencilOpState, setBack, depth.backStencilOpState);
}

void RenderBackendGLES::UpdateDepthStencilState(const GraphicsState& graphicsState)
{
    UpdateDepthState(graphicsState);
    UpdateStencilState(graphicsState);
}

void RenderBackendGLES::UpdateBlendState(const GraphicsState& graphicsState)
{
    const auto& blend = graphicsState.colorBlendState;
    auto& cBlend = cacheState_.colorBlendState;
    for (GLuint i = 0; i < blend.colorAttachmentCount; i++) {
        const auto& blendState = blend.colorAttachments[i];
        auto& cBlendState = cBlend.colorAttachments[i];
        if (blendState.colorWriteMask != cBlendState.colorWriteMask) {
            cBlendState.colorWriteMask = blendState.colorWriteMask;
            glColorMaski(i, IS_BIT_GL(cBlendState.colorWriteMask, CORE_COLOR_COMPONENT_R_BIT),
                IS_BIT_GL(cBlendState.colorWriteMask, CORE_COLOR_COMPONENT_G_BIT),
                IS_BIT_GL(cBlendState.colorWriteMask, CORE_COLOR_COMPONENT_B_BIT),
                IS_BIT_GL(cBlendState.colorWriteMask, CORE_COLOR_COMPONENT_A_BIT));
        }

        // Check if blend state has changed
        bool factorsChanged = false;
        bool opsChanged = false;

        if (blendState.enableBlend) {
            factorsChanged = !CompareBlendFactors(cBlendState, blendState);
            opsChanged = !CompareBlendOps(cBlendState, blendState);
        }

        if (blendState.enableBlend != cBlendState.enableBlend || factorsChanged || opsChanged) {
            cBlendState.enableBlend = blendState.enableBlend;
            if (blendState.enableBlend) {
                glEnablei(GL_BLEND, i);
                if (factorsChanged) {
                    SetBlendFactors(cBlendState, blendState);
                    glBlendFuncSeparatei(i, GetBlendFactor(cBlendState.srcColorBlendFactor),
                        GetBlendFactor(cBlendState.dstColorBlendFactor),
                        GetBlendFactor(cBlendState.srcAlphaBlendFactor),
                        GetBlendFactor(cBlendState.dstAlphaBlendFactor));
                }
                if (opsChanged) {
                    SetBlendOps(cBlendState, blendState);
                    glBlendEquationSeparatei(
                        i, GetBlendOp(cBlendState.colorBlendOp), GetBlendOp(cBlendState.alphaBlendOp));
                }
            } else {
                glDisablei(GL_BLEND, i);
            }
        }
    }
    if (!IS_BIT(dynamicStateFlags_, CORE_DYNAMIC_STATE_BLEND_CONSTANTS)) {
        if (!Compare(cBlend.colorBlendConstants, blend.colorBlendConstants)) {
            Set(cBlend.colorBlendConstants, blend.colorBlendConstants);
            glBlendColor(blend.colorBlendConstants[Gles::RED_INDEX], blend.colorBlendConstants[Gles::GREEN_INDEX],
                blend.colorBlendConstants[Gles::BLUE_INDEX], blend.colorBlendConstants[Gles::ALPHA_INDEX]);
        }
    }
    // logicOps in blend not supported on GLES
}

void RenderBackendGLES::UpdateRasterizationState(const GraphicsState& graphicsState)
{
    const auto& rs = graphicsState.rasterizationState;
    auto& crs = cacheState_.rasterizationState;
    // save, since we need to hack for non fill modes etc ! (possibly need shader help for lines...)
    polygonMode_ = rs.polygonMode;
#if RENDER_HAS_GL_BACKEND
    if (rs.polygonMode != crs.polygonMode) {
        crs.polygonMode = rs.polygonMode;
        SetPolygonMode(rs);
    }
#endif
    if (rs.enableDepthClamp != crs.enableDepthClamp) {
        crs.enableDepthClamp = rs.enableDepthClamp;
        // NOT SUPPORTED    (needs an extension)
    }
    if (rs.enableRasterizerDiscard != crs.enableRasterizerDiscard) {
        crs.enableRasterizerDiscard = rs.enableRasterizerDiscard;
        SetState(GL_RASTERIZER_DISCARD, rs.enableRasterizerDiscard);
    }
    if (rs.enableDepthBias != crs.enableDepthBias) {
        crs.enableDepthBias = rs.enableDepthBias;
        SetState(GL_POLYGON_OFFSET_FILL, rs.enableDepthBias);
    }
    if (!IS_BIT(dynamicStateFlags_, CORE_DYNAMIC_STATE_DEPTH_BIAS)) {
        if ((rs.depthBiasConstantFactor != crs.depthBiasConstantFactor) ||
            (rs.depthBiasSlopeFactor != crs.depthBiasSlopeFactor)) {
            crs.depthBiasConstantFactor = rs.depthBiasConstantFactor;
            crs.depthBiasSlopeFactor = rs.depthBiasSlopeFactor;
            glPolygonOffset(rs.depthBiasSlopeFactor, rs.depthBiasConstantFactor);
        }
        // depthBiasClamp NOT SUPPORTED    (needs an extension)
    }
    // If cull mode Flags change...
    if (rs.cullModeFlags != crs.cullModeFlags) {
        crs.cullModeFlags = rs.cullModeFlags;
        SetCullMode(crs);
    }
    auto frontFace = rs.frontFace;
    if (!renderingToDefaultFbo_) {
        // Flip winding for default fbo.
        if (frontFace == FrontFace::CORE_FRONT_FACE_COUNTER_CLOCKWISE) {
            frontFace = FrontFace::CORE_FRONT_FACE_CLOCKWISE;
        } else if (frontFace == FrontFace::CORE_FRONT_FACE_CLOCKWISE) {
            frontFace = FrontFace::CORE_FRONT_FACE_COUNTER_CLOCKWISE;
        }
    }
    if (frontFace != crs.frontFace) {
        crs.frontFace = frontFace;
        SetFrontFace(crs);
    }
    if (!IS_BIT(dynamicStateFlags_, CORE_DYNAMIC_STATE_LINE_WIDTH)) {
        if (rs.lineWidth != crs.lineWidth) {
            crs.lineWidth = rs.lineWidth;
            glLineWidth(rs.lineWidth);
        }
    }
}

void RenderBackendGLES::DoGraphicsState(const GraphicsState& graphicsState)
{
    /// GRAPHICSSTATE     inputAssembly
    const auto& ia = graphicsState.inputAssembly;
    if (ia.enablePrimitiveRestart != graphicsState.inputAssembly.enablePrimitiveRestart) {
        auto& cia = cacheState_.inputAssembly;
        cia.enablePrimitiveRestart = ia.enablePrimitiveRestart;
        SetState(GL_PRIMITIVE_RESTART_FIXED_INDEX, ia.enablePrimitiveRestart);
    }
    topology_ = ia.primitiveTopology;
    UpdateRasterizationState(graphicsState);
    UpdateDepthStencilState(graphicsState);
    UpdateBlendState(graphicsState);
}

void RenderBackendGLES::SetViewport(const RenderPassDesc::RenderArea& ra, const ViewportDesc& vd)
{
    // NOTE: viewportdesc is in floats?!?
    bool forceV = false;
    bool forceD = false;
    if (!viewportPrimed_) {
        viewportPrimed_ = true;
        forceV = true;
        forceD = true;
    }
    if ((vd.x != viewport_.x) || (vd.y != viewport_.y) || (vd.width != viewport_.width) ||
        (vd.height != viewport_.height)) {
        forceV = true;
    }
    if ((vd.minDepth != viewport_.minDepth) || (vd.maxDepth != viewport_.maxDepth)) {
        forceD = true;
    }

    if (forceV) {
        viewport_.x = vd.x;
        viewport_.y = vd.y;
        viewport_.width = vd.width;
        viewport_.height = vd.height;
        viewportUpdated_ = true;
    }
    if (forceD) {
        viewport_.minDepth = vd.minDepth;
        viewport_.maxDepth = vd.maxDepth;
        viewportDepthRangeUpdated_ = true;
    }
}

void RenderBackendGLES::SetScissor(const RenderPassDesc::RenderArea& ra, const ScissorDesc& sd)
{
    // NOTE: scissordesc is in floats?!?
    bool force = false;
    if (!scissorPrimed_) {
        scissorPrimed_ = true;
        force = true;
    }
    if ((sd.offsetX != scissorBox_.offsetX) || (sd.offsetY != scissorBox_.offsetY) ||
        (sd.extentWidth != scissorBox_.extentWidth) || (sd.extentHeight != scissorBox_.extentHeight)) {
        force = true;
    }
    if (force) {
        scissorBox_ = sd;
        scissorBoxUpdated_ = true;
    }
}

void RenderBackendGLES::FlushViewportScissors()
{
    if (!currentFrameBuffer_) {
        return;
    }
    bool force = false;
    if (scissorViewportSetDefaultFbo_ != renderingToDefaultFbo_) {
        force = true;
        scissorViewportSetDefaultFbo_ = renderingToDefaultFbo_;
    }
    if ((viewportUpdated_) || (force)) {
        viewportUpdated_ = false;
        // Handle top-left / bottom-left origin conversion
        PLUGIN_ASSERT(currentFrameBuffer_);
        GLint y = static_cast<GLint>(viewport_.y);
        const GLsizei h = static_cast<GLsizei>(viewport_.height);
        if (renderingToDefaultFbo_) {
            const GLsizei fh = static_cast<GLint>(currentFrameBuffer_->height);
            y = fh - (y + h);
        }
        glViewport(static_cast<GLint>(viewport_.x), y, static_cast<GLsizei>(viewport_.width), h);
    }
    if ((scissorBoxUpdated_) || (force)) {
        scissorBoxUpdated_ = false;
        // Handle top-left / bottom-left origin conversion
        GLint y = static_cast<GLint>(scissorBox_.offsetY);
        const GLsizei h = static_cast<GLsizei>(scissorBox_.extentHeight);
        if (renderingToDefaultFbo_) {
            const GLsizei fh = static_cast<GLint>(currentFrameBuffer_->height);
            y = fh - (y + h);
        }
        glScissor(static_cast<GLint>(scissorBox_.offsetX), y, static_cast<GLsizei>(scissorBox_.extentWidth), h);
    }
    if (viewportDepthRangeUpdated_) {
        viewportDepthRangeUpdated_ = false;
        glDepthRangef(viewport_.minDepth, viewport_.maxDepth);
    }
}
RENDER_END_NAMESPACE()