Commit 3a4f401b authored Oct 03, 2018 by Chia-I Wu

renderengine: clamp XYZ to [0.0, 1.0] in shaders

texture2D can return strange negative values for some YUV textures.
That should be a driver bug.  But with scRGB and floating-point
formats, we cannot be sure that colors will always stay non-negative
after conversion to XYZ.  We need to clamp XYZ to [0.0, 1.0] such
that the following color processing behaves as expected.

Bug: 116864006
Test: manual
Change-Id: I8f432c63b800edc11ce3d86536192a5547144ca5

parent 9bdd64de

services/surfaceflinger/RenderEngine/gl/ProgramCache.cpp

+1 −1

Original line number	Diff line number	Diff line
		@@ -574,7 +574,7 @@ String8 ProgramCache::generateFragmentShader(const Key& needs) {
		fs << "uniform mat4 inputTransformMatrix;";
		fs << R"__SHADER__(
		highp vec3 InputTransform(const highp vec3 color) {
		return vec3(inputTransformMatrix * vec4(color, 1.0));
		return clamp(vec3(inputTransformMatrix * vec4(color, 1.0)), 0.0, 1.0);
		}
		)__SHADER__";
		} else {