Ensure all vertex attributes (except zero that we always use) are disabled after a resetContext.
Review URL: http://codereview.appspot.com/5309043/
git-svn-id: http://skia.googlecode.com/svn/trunk@2494 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrGpuGLShaders.cpp b/src/gpu/GrGpuGLShaders.cpp
index feb6a1f..71444da 100644
--- a/src/gpu/GrGpuGLShaders.cpp
+++ b/src/gpu/GrGpuGLShaders.cpp
@@ -325,6 +325,8 @@
this->hasExtension("GL_OES_standard_derivatives");
}
+ GR_GL_GetIntegerv(gl, GR_GL_MAX_VERTEX_ATTRIBS, &fMaxVertexAttribs);
+
fProgramData = NULL;
fProgramCache = new ProgramCache(gl, glslVersion);
@@ -361,14 +363,27 @@
void GrGpuGLShaders::resetContext() {
INHERITED::resetContext();
- fHWGeometryState.fVertexLayout = 0;
fHWGeometryState.fVertexOffset = ~0;
- GL_CALL(DisableVertexAttribArray(GrGLProgram::ColorAttributeIdx()));
- GL_CALL(DisableVertexAttribArray(GrGLProgram::EdgeAttributeIdx()));
- for (int t = 0; t < kMaxTexCoords; ++t) {
- GL_CALL(DisableVertexAttribArray(GrGLProgram::TexCoordAttributeIdx(t)));
+
+ // Third party GL code may have left vertex attributes enabled. Some GL
+ // implementations (osmesa) may read vetex attributes that are not required
+ // by the current shader. Therefore, we have to ensure that only the
+ // attributes we require for the current draw are enabled or we may cause an
+ // invalid read.
+
+ // Disable all vertex layout bits so that next flush will assume all
+ // optional vertex attributes are disabled.
+ fHWGeometryState.fVertexLayout = 0;
+
+ // We always use the this attribute and assume it is always enabled.
+ int posAttrIdx = GrGLProgram::PositionAttributeIdx();
+ GL_CALL(EnableVertexAttribArray(posAttrIdx));
+ // Disable all other vertex attributes.
+ for (int va = 0; va < fMaxVertexAttribs; ++va) {
+ if (va != posAttrIdx) {
+ GL_CALL(DisableVertexAttribArray(va));
+ }
}
- GL_CALL(EnableVertexAttribArray(GrGLProgram::PositionAttributeIdx()));
fHWProgramID = 0;
}