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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

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.
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    GLSL discard statement

Tests:
 + dEQP-GLES2.functional.shaders.discard.*

Includes:
 + Unconditional discard
 + Conditional discard with compile-time false condition
 + Conditional discard based on uniform value
 + Conditional discard based on varying value
 + Conditional discard based on texture lookup result
 + Discard in main()
 + Discard in user-defined function
 + Discard inside static for loop
 + Discard inside uniform for loop
 + Discard inside static loop in user-defined function

Excludes:
 + Effects on depth buffer values
 + Discard when rendering lines and points

Description:

Two triangles forming a quad is rendered with a fragment shader that
exercises the GLSL discard statement. A reference image is rendered
using a simple C function that implements the same discard condition.
Results are checked by reading the pixels and comparing image against
the reference.