Implement support for mixed sampled render targets

src/gpu/gl/GrGLGpu.cpp

Index: src/gpu/gl/GrGLGpu.cpp
diff --git a/src/gpu/gl/GrGLGpu.cpp b/src/gpu/gl/GrGLGpu.cpp
index 954ecc4f61c3401ba89f753e5323f27e996e217f..e0a2cb7d7ba85a32712bebb69b1d16e98e5af597 100644
--- a/src/gpu/gl/GrGLGpu.cpp
+++ b/src/gpu/gl/GrGLGpu.cpp
@@ -301,6 +301,7 @@ void GrGLGpu::onResetContext(uint32_t resetBits) {
 
     if (resetBits & kMSAAEnable_GrGLBackendState) {
         fMSAAEnabled = kUnknown_TriState;
+        fCoverageModulationEnabled = kUnknown_TriState;
     }
 
     fHWActiveTextureUnitIdx = -1; // invalid
@@ -435,6 +436,9 @@ GrRenderTarget* GrGLGpu::onWrapBackendRenderTarget(const GrBackendRenderTargetDe
     idDesc.fRTFBOID = static_cast<GrGLuint>(wrapDesc.fRenderTargetHandle);
     idDesc.fMSColorRenderbufferID = 0;
     idDesc.fTexFBOID = GrGLRenderTarget::kUnresolvableFBOID;
+    idDesc.fSampleConfig = (wrapDesc.fFlags & kStencilMSAAOnly_GrBackendRenderTargetFlags) ?
+                           GrRenderTarget::kStencil_SampleConfig :
+                           GrRenderTarget::kUnified_SampleConfig;
     idDesc.fLifeCycle = GrGpuResource::kWrapped_LifeCycle;
 
     GrSurfaceDesc desc;
@@ -782,6 +786,7 @@ static bool renderbuffer_storage_msaa(GrGLContext& ctx,
     switch (ctx.caps()->msFBOType()) {
         case GrGLCaps::kDesktop_ARB_MSFBOType:
         case GrGLCaps::kDesktop_EXT_MSFBOType:
+        case GrGLCaps::kMixedSamples_MSFBOType:
         case GrGLCaps::kES_3_0_MSFBOType:
             GL_ALLOC_CALL(ctx.interface(),
                             RenderbufferStorageMultisample(GR_GL_RENDERBUFFER,
@@ -818,6 +823,9 @@ bool GrGLGpu::createRenderTargetObjects(const GrSurfaceDesc& desc, bool budgeted
     idDesc->fTexFBOID = 0;
     idDesc->fLifeCycle = budgeted ? GrGpuResource::kCached_LifeCycle :
                                     GrGpuResource::kUncached_LifeCycle;
+    idDesc->fSampleConfig = GrGLCaps::kMixedSamples_MSFBOType ==
+                            this->glCaps().msFBOType() ? GrRenderTarget::kStencil_SampleConfig :
+                                                         GrRenderTarget::kUnified_SampleConfig;
 
     GrGLenum status;
 
@@ -1139,7 +1147,7 @@ bool GrGLGpu::createStencilAttachmentForRenderTarget(GrRenderTarget* rt, int wid
     SkASSERT(width >= rt->width());
     SkASSERT(height >= rt->height());
 
-    int samples = rt->numSamples();
+    int samples = rt->numSamples(GrRenderTarget::kStencil_BufferBit);
     GrGLStencilAttachment::IDDesc sbDesc;
 
     int stencilFmtCnt = this->glCaps().stencilFormats().count();
@@ -2096,9 +2104,10 @@ void GrGLGpu::flushStencil(const GrStencilSettings& stencilSettings) {
 }
 
 void GrGLGpu::flushHWAAState(GrRenderTarget* rt, bool useHWAA) {
-    SkASSERT(!useHWAA || rt->isMultisampled());
+    SkASSERT(!useHWAA || rt->isMultisampled(GrRenderTarget::kAny_BufferBits));
 
-    if (kGL_GrGLStandard == this->glStandard()) {
+    if (kGL_GrGLStandard == this->glStandard() ||
+        this->glCaps().fbMixedSamplesSupport()) {
         if (useHWAA) {
             if (kYes_TriState != fMSAAEnabled) {
                 GL_CALL(Enable(GR_GL_MULTISAMPLE));
@@ -2111,6 +2120,19 @@ void GrGLGpu::flushHWAAState(GrRenderTarget* rt, bool useHWAA) {
             }
         }
     }
+    if (this->glCaps().fbMixedSamplesSupport()) {
+        if (useHWAA && GrRenderTarget::kStencil_SampleConfig == rt->sampleConfig()) {
+            if (kYes_TriState != fCoverageModulationEnabled) {
+                GL_CALL(CoverageModulation(GR_GL_RGBA));
+                fCoverageModulationEnabled = kYes_TriState;
+            }
+        } else {
+            if (kNo_TriState != fCoverageModulationEnabled) {
+                GL_CALL(CoverageModulation(GR_GL_NONE));
+                fCoverageModulationEnabled = kNo_TriState;
+            }
+        }
+    }
 }
 
 void GrGLGpu::flushBlend(const GrXferProcessor::BlendInfo& blendInfo) {