xref: /third_party/vk-gl-cts/doc/testspecs/GLES3/functional.primitive_bounding_box.txt

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drawElements Quality Program Test Specification
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Copyright 2014 The Android Open Source Project

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

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distributed under the License is distributed on an "AS IS" BASIS,
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    GL_EXT_primitive_bounding_box extension tests

Tests:
 + dEQP-GLES31.functional.primitive_bounding_box.*

Includes:
 + State query tests
 + Primitive render tests
   - All basic primitives: triangles, (wide) lines, (wide) points
   - Set bounding box with gl_BoundingBoxEXT and PrimitiveBoundingBoxEXT
   - Rendering with and without tessellation and/or geometry stages
   - Rendering with correct, too large, and too small bounding boxes
 + Depth render tests
   - Render pattern and hint the final depth range with bounding box
   - Test with built-in depth and user defined (gl_FragDepth) depth
 + Blit tests
   - Blit should not be affected by the bounding box
 + Clear tests
   - Clears should not be affected by the bounding box

Excludes:
 + Special floating point values (NaN, Inf, etc.)
 + Rendering with separate shader pipelines
 + Rendering discardable geometry with fragment shaders that have
   side-effects (memory writes)
 + Rendering discardable geometry with active transform feedback

Description:

state_query.* cases test the global PRIMITIVE_BOUNDING_BOX_EXT state.
Tests set the state to certain values and then query the state using
different methods.

triangles.*, (wide_)lines.*, (wide_)points.* cases set the primitive
bounding box and render a test pattern. Rendering results within the
bounding box are then verified.

"global_state.*" cases set the bounding box of the whole test pattern
using the PRIMITIVE_BOUNDING_BOX_EXT state. "tessellation_set_per_draw.*"
cases set the bounding box of the whole test pattern using
gl_BoundingBoxEXT output variable. "tessellation_set_per_draw.*" cases
set the bounding box for each (tessellation input) primitive separately.

"*_bbox_equal" cases set the bounding box to tightly cover the primitive
or the whole pattern. In "*_bbox_larger" cases, the bounding box is set
to be larger than the rendered pattern/primitive and in "*_bbox_smaller"
cases, the bounding box is set to cover only a subset of the pattern.
In these subset cases, only the area covered by the bounding box is
verified.

triangles.* cases render a grid with yellow and green cells. Cells are
in random order. Result image verification is done by simply checking
that the viewport does not contain any background-colored pixels within
the pattern area.

(wide_)points.* cases render a pattern of green and blue points.
Verification checks that no points within the bounding box area are
missing and have the correct size. Size test is intended to prevent
partially rendered points from passing the test.

(wide_)lines.* cases render a pattern of green and blue lines.
Verification checks the number and the width of separate lines within
bounding box area. Number-of-lines check prevents accepting rendering
results with missing lines and the line width check prevents accepting
partially rendered lines.

depth.* cases render multiple layers with varying depth values while
hint the resulting depth range with primitive bounding box. In
"builtin_depth.*" cases, depth is set by the rasterizer. In
"user_defined_depth.*" cases, depth is set in the fragment shader using
gl_FragDepth. Verification checks that only the topmost layer is visible.

blit_fbo.* cases do framebuffer blits with different bounding box values.
Bounding box values should not affect blitting.

clear.* cases do full and scissored framebuffer clears. Since clears are
not affected by the bounding box, verification is done by simply comparing
rendering result with bounding box set to cover full viewport and rendering
result with bounding box set to arbitrary values. In *_with_triangles cases,
some geometry is rendered between clears with properly set bounding box.

call_order.* cases render a scene with different relative order of
glViewport and glPrimitiveBoundingBox. Tests verify that the bounding box
for a draw command is calculated from the current state when draw command
is issued (i.e. changing call order of state setting functions does not
change ther result).