Use smoothstep to eliminate branches in AA shader
Change-Id: If4ecb1a9446f29b2f8444f5cee551f863c1993e8
diff --git a/libs/hwui/ProgramCache.cpp b/libs/hwui/ProgramCache.cpp
index d67bfbe..8a9a2ac 100644
--- a/libs/hwui/ProgramCache.cpp
+++ b/libs/hwui/ProgramCache.cpp
@@ -129,9 +129,7 @@
"uniform vec4 color;\n";
const char* gFS_Uniforms_AA =
"uniform float boundaryWidth;\n"
- "uniform float inverseBoundaryWidth;\n"
- "uniform float boundaryLength;\n"
- "uniform float inverseBoundaryLength;\n";
+ "uniform float boundaryLength;\n";
const char* gFS_Header_Uniforms_PointHasBitmap =
"uniform vec2 textureDimension;\n"
"uniform float pointSize;\n";
@@ -242,16 +240,9 @@
const char* gFS_Main_ModulateColor_ApplyGamma =
" fragColor *= pow(color.a, gamma);\n";
const char* gFS_Main_AccountForAA =
- " if (widthProportion < boundaryWidth) {\n"
- " fragColor *= (widthProportion * inverseBoundaryWidth);\n"
- " } else if (widthProportion > (1.0 - boundaryWidth)) {\n"
- " fragColor *= ((1.0 - widthProportion) * inverseBoundaryWidth);\n"
- " }\n"
- " if (lengthProportion < boundaryLength) {\n"
- " fragColor *= (lengthProportion * inverseBoundaryLength);\n"
- " } else if (lengthProportion > (1.0 - boundaryLength)) {\n"
- " fragColor *= ((1.0 - lengthProportion) * inverseBoundaryLength);\n"
- " }\n";
+ " fragColor *= (1.0 - smoothstep(boundaryWidth, 0.5, abs(0.5 - widthProportion)))\n"
+ " * (1.0 - smoothstep(boundaryLength, 0.5, abs(0.5 - lengthProportion)));\n";
+
const char* gFS_Main_FetchTexture[2] = {
// Don't modulate
" fragColor = texture2D(sampler, outTexCoords);\n",