1/*
2 * Copyright 2021 Google LLC
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#include "src/core/SkBlendModeBlender.h"
9#include "src/core/SkReadBuffer.h"
10#include "src/core/SkWriteBuffer.h"
11
12#if SK_SUPPORT_GPU
13#include "src/gpu/GrFragmentProcessor.h"
14#include "src/gpu/effects/GrBlendFragmentProcessor.h"
15#endif
16
17sk_sp<SkBlender> SkBlender::Mode(SkBlendMode mode) {
18#define RETURN_SINGLETON_BLENDER(m)                        \
19    case m: {                                              \
20        static auto* sBlender = new SkBlendModeBlender{m}; \
21        return sk_ref_sp(sBlender);                        \
22    }
23
24    switch (mode) {
25        RETURN_SINGLETON_BLENDER(SkBlendMode::kClear)
26        RETURN_SINGLETON_BLENDER(SkBlendMode::kSrc)
27        RETURN_SINGLETON_BLENDER(SkBlendMode::kDst)
28        RETURN_SINGLETON_BLENDER(SkBlendMode::kSrcOver)
29        RETURN_SINGLETON_BLENDER(SkBlendMode::kDstOver)
30        RETURN_SINGLETON_BLENDER(SkBlendMode::kSrcIn)
31        RETURN_SINGLETON_BLENDER(SkBlendMode::kDstIn)
32        RETURN_SINGLETON_BLENDER(SkBlendMode::kSrcOut)
33        RETURN_SINGLETON_BLENDER(SkBlendMode::kDstOut)
34        RETURN_SINGLETON_BLENDER(SkBlendMode::kSrcATop)
35        RETURN_SINGLETON_BLENDER(SkBlendMode::kDstATop)
36        RETURN_SINGLETON_BLENDER(SkBlendMode::kXor)
37        RETURN_SINGLETON_BLENDER(SkBlendMode::kPlus)
38        RETURN_SINGLETON_BLENDER(SkBlendMode::kModulate)
39        RETURN_SINGLETON_BLENDER(SkBlendMode::kScreen)
40        RETURN_SINGLETON_BLENDER(SkBlendMode::kOverlay)
41        RETURN_SINGLETON_BLENDER(SkBlendMode::kDarken)
42        RETURN_SINGLETON_BLENDER(SkBlendMode::kLighten)
43        RETURN_SINGLETON_BLENDER(SkBlendMode::kColorDodge)
44        RETURN_SINGLETON_BLENDER(SkBlendMode::kColorBurn)
45        RETURN_SINGLETON_BLENDER(SkBlendMode::kHardLight)
46        RETURN_SINGLETON_BLENDER(SkBlendMode::kSoftLight)
47        RETURN_SINGLETON_BLENDER(SkBlendMode::kDifference)
48        RETURN_SINGLETON_BLENDER(SkBlendMode::kExclusion)
49        RETURN_SINGLETON_BLENDER(SkBlendMode::kMultiply)
50        RETURN_SINGLETON_BLENDER(SkBlendMode::kHue)
51        RETURN_SINGLETON_BLENDER(SkBlendMode::kSaturation)
52        RETURN_SINGLETON_BLENDER(SkBlendMode::kColor)
53        RETURN_SINGLETON_BLENDER(SkBlendMode::kLuminosity)
54    }
55
56    SkDEBUGFAILF("invalid blend mode %d", (int)mode);
57    return nullptr;
58
59#undef RETURN_SINGLETON_BLENDER
60}
61
62sk_sp<SkFlattenable> SkBlendModeBlender::CreateProc(SkReadBuffer& buffer) {
63    SkBlendMode mode = buffer.read32LE(SkBlendMode::kLastMode);
64    return SkBlender::Mode(mode);
65}
66
67void SkBlendModeBlender::flatten(SkWriteBuffer& buffer) const {
68    buffer.writeInt((int)fMode);
69}
70
71#if SK_SUPPORT_GPU
72std::unique_ptr<GrFragmentProcessor> SkBlendModeBlender::asFragmentProcessor(
73        std::unique_ptr<GrFragmentProcessor> srcFP,
74        std::unique_ptr<GrFragmentProcessor> dstFP,
75        const GrFPArgs& fpArgs) const {
76    // Note that for the final blend onto the canvas, we should prefer to use the GrXferProcessor
77    // instead of a SkBlendModeBlender to perform the blend. The Xfer processor is able to perform
78    // coefficient-based blends directly, without readback. This will be much more efficient.
79    return GrBlendFragmentProcessor::Make(
80            std::move(srcFP), GrFragmentProcessor::UseDestColorAsInput(std::move(dstFP)), fMode);
81}
82#endif
83
84skvm::Color SkBlendModeBlender::onProgram(skvm::Builder* p, skvm::Color src, skvm::Color dst,
85                                          const SkColorInfo& colorInfo, skvm::Uniforms* uniforms,
86                                          SkArenaAlloc* alloc) const {
87    return p->blend(fMode, src, dst);
88}
89