Fix OpenGL mix-blending when the source alpha is 0. (bug 1281593 part 2, r=mstange)

2016-08-02 11:43:15 -07:00
parent 36f49bc3ae
commit a7dbcdce91
1 changed files with 1 additions and 1 deletions
--- a/gfx/layers/opengl/OGLShaderProgram.cpp
+++ b/gfx/layers/opengl/OGLShaderProgram.cpp
@@ -737,7 +737,7 @@ ProgramProfileOGL::BuildMixBlender(const ShaderConfigOGL& aConfig, std::ostrings
  fs << "    return color;" << endl;
  fs << "  }" << endl;
  fs << "  if (color.a == 0.0) {" << endl;
-  fs << "    return backdrop;" << endl;
+  fs << "    return vec4(0.0, 0.0, 0.0, 0.0);" << endl;
  fs << "  }" << endl;

  // The spec assumes there is no premultiplied alpha. The backdrop is always