doc/testspecs/GLES3/functional.rasterizer_discard.txt

-------------------------------------------------------------------------
drawElements Quality Program Test Specification
-----------------------------------------------

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

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.
-------------------------------------------------------------------------
    Rasterizer discard tests

Tests:
 + dEQP-GLES3.functional.rasterizer_discard.*

Includes:
 + Correct discarding of following operations are tested:
	- All primitive draw modes
	- Color clears & writes
	- Depth clears & writes
	- Stencil clears & writes
 + Following test cases are created:
	- Discard test for default framebuffer
	- Discard test for default framebuffer with scissor test enabled
	- Discard test for a framebuffer object

Excludes:

Description:

Rasterizer discard functionality is tested by first clearing color, depth
and stencil buffers to initial values. Next, rasterizer discarding is
enabled, and an operation is performed. Rasterizer discarding is disabled
afterwards. For depth and stencil clears, series of primitives are drawn
to make sure that the buffer clear operations were ignored.

Finally, framebuffer pixels are read. If red color is present or blue
color is not present, the performed operation was not discarded according
to specification and the test fails.

This procedure is performed for both the default framebuffer and an FBO
with color, depth and stencil attachments. Additionally, default
framebuffer discards are tested with scissor test enabled.