When applying a color matrix, unpremultiply the source, and premultiply the
result. If the input color is missing, set to all-zeros or all-ones as
appropriate. Add an alpha test case to the colormatrix GM.
Review URL: http://codereview.appspot.com/5520046/
git-svn-id: http://skia.googlecode.com/svn/trunk@2974 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrGLProgram.cpp b/src/gpu/GrGLProgram.cpp
index ce87b85..2e391e3 100644
--- a/src/gpu/GrGLProgram.cpp
+++ b/src/gpu/GrGLProgram.cpp
@@ -373,7 +373,8 @@
*/
static void addColorMatrix(GrStringBuilder* fsCode, const char * outputVar,
const char* inColor) {
- fsCode->appendf("%s = %s * %s + %s;\n", outputVar, COL_MATRIX_UNI_NAME, inColor, COL_MATRIX_VEC_UNI_NAME);
+ fsCode->appendf("\t%s = %s * vec4(%s.rgb / %s.a, %s.a) + %s;\n", outputVar, COL_MATRIX_UNI_NAME, inColor, inColor, inColor, COL_MATRIX_VEC_UNI_NAME);
+ fsCode->appendf("\t%s.rgb *= %s.a;\n", outputVar, outputVar);
}
namespace {
@@ -652,6 +653,19 @@
#endif
}
+const char* GrGLProgram::adjustInColor(const GrStringBuilder& inColor) const {
+ const char* color;
+ if (inColor.size()) {
+ return inColor.c_str();
+ } else {
+ if (ProgramDesc::kSolidWhite_ColorInput == fProgramDesc.fColorInput) {
+ return all_ones_vec(4);
+ } else {
+ return all_zeros_vec(4);
+ }
+ }
+}
+
bool GrGLProgram::genProgram(const GrGLInterface* gl,
GrGLSLGeneration glslGeneration,
GrGLProgram::CachedData* programData) const {
@@ -818,16 +832,7 @@
wroteFragColorZero = true;
} else if (SkXfermode::kDst_Mode != fProgramDesc.fColorFilterXfermode) {
segments.fFSCode.appendf("\tvec4 filteredColor;\n");
- const char* color;
- if (inColor.size()) {
- color = inColor.c_str();
- } else {
- if (ProgramDesc::kSolidWhite_ColorInput == fProgramDesc.fColorInput) {
- color = all_ones_vec(4);
- } else {
- color = all_zeros_vec(4);
- }
- }
+ const char* color = adjustInColor(inColor);
addColorFilter(&segments.fFSCode, "filteredColor", uniformCoeff,
colorCoeff, color);
inColor = "filteredColor";
@@ -842,7 +847,8 @@
programData->fUniLocations.fColorMatrixUni = kUseUniform;
programData->fUniLocations.fColorMatrixVecUni = kUseUniform;
segments.fFSCode.appendf("\tvec4 matrixedColor;\n");
- addColorMatrix(&segments.fFSCode, "matrixedColor", inColor.c_str());
+ const char* color = adjustInColor(inColor);
+ addColorMatrix(&segments.fFSCode, "matrixedColor", color);
inColor = "matrixedColor";
}