GrGLInterface: Add support for NV_framebuffer_mixed_samples

Import glCoverageModulation if NV_framebuffer_mixed samples
is available

BUG=skia:3177

Review URL: https://codereview.chromium.org/993363002

4 files changed, 21 insertions, 0 deletions

diff --git a/src/gpu/gl/GrGLAssembleInterface.cpp b/src/gpu/gl/GrGLAssembleInterface.cpp
index c91da9e6c7..6a4fbe20e0 100644
--- a/src/gpu/gl/GrGLAssembleInterface.cpp
+++ b/src/gpu/gl/GrGLAssembleInterface.cpp
@@ -278,6 +278,10 @@ const GrGLInterface* GrGLAssembleGLInterface(void* ctx, GrGLGetProc get) {
         GET_PROC_SUFFIX(PathMemoryGlyphIndexArray, NV);
     }
 
+    if (extensions.has("GL_NV_framebuffer_mixed_samples")) {
+        GET_PROC_SUFFIX(CoverageModulation, NV);
+    }
+
     if (extensions.has("GL_EXT_debug_marker")) {
         GET_PROC_SUFFIX(InsertEventMarker, EXT);
         GET_PROC_SUFFIX(PushGroupMarker, EXT);
@@ -519,6 +523,10 @@ const GrGLInterface* GrGLAssembleGLESInterface(void* ctx, GrGLGetProc get) {
         GET_PROC_SUFFIX(PathMemoryGlyphIndexArray, NV);
     }
 
+    if (extensions.has("GL_NV_framebuffer_mixed_samples")) {
+        GET_PROC_SUFFIX(CoverageModulation, NV);
+    }
+
     interface->fStandard = kGLES_GrGLStandard;
     interface->fExtensions.swap(&extensions);
 
diff --git a/src/gpu/gl/GrGLCaps.cpp b/src/gpu/gl/GrGLCaps.cpp
index c9009b9053..fe52a540c6 100644
--- a/src/gpu/gl/GrGLCaps.cpp
+++ b/src/gpu/gl/GrGLCaps.cpp
@@ -54,6 +54,7 @@ void GrGLCaps::reset() {
     fFBFetchNeedsCustomOutput = false;
     fFBFetchColorName = NULL;
     fFBFetchExtensionString = NULL;
+    fFBMixedSamplesSupport = false;
 
     fReadPixelsSupportedCache.reset();
 }
@@ -99,6 +100,7 @@ GrGLCaps& GrGLCaps::operator= (const GrGLCaps& caps) {
     fFBFetchNeedsCustomOutput = caps.fFBFetchNeedsCustomOutput;
     fFBFetchColorName = caps.fFBFetchColorName;
     fFBFetchExtensionString = caps.fFBFetchExtensionString;
+    fFBMixedSamplesSupport = caps.fFBMixedSamplesSupport;
 
     return *this;
 }
@@ -371,6 +373,8 @@ bool GrGLCaps::init(const GrGLContextInfo& ctxInfo, const GrGLInterface* gli) {
         fNvprSupport = kNone_NvprSupport;
     }
 
+    fFBMixedSamplesSupport = ctxInfo.hasExtension("GL_NV_framebuffer_mixed_samples");
+
     fGpuTracingSupport = ctxInfo.hasExtension("GL_EXT_debug_marker");
 
     // For now these two are equivalent but we could have dst read in shader via some other method
diff --git a/src/gpu/gl/GrGLCaps.h b/src/gpu/gl/GrGLCaps.h
index d81e34b35e..53587e1ad6 100644
--- a/src/gpu/gl/GrGLCaps.h
+++ b/src/gpu/gl/GrGLCaps.h
@@ -178,6 +178,8 @@ public:
 
     const char* fbFetchExtensionString() const { return fFBFetchExtensionString; }
 
+    bool fbMixedSamplesSupport() const { return fFBMixedSamplesSupport; }
+
     InvalidateFBType invalidateFBType() const { return fInvalidateFBType; }
 
     /// What type of buffer mapping is supported?
@@ -389,6 +391,7 @@ private:
     bool fDropsTileOnZeroDivide : 1;
     bool fFBFetchSupport : 1;
     bool fFBFetchNeedsCustomOutput : 1;
+    bool fFBMixedSamplesSupport : 1;
 
     const char* fFBFetchColorName;
     const char* fFBFetchExtensionString;
diff --git a/src/gpu/gl/GrGLInterface.cpp b/src/gpu/gl/GrGLInterface.cpp
index dba005976f..2e3dd1f039 100644
--- a/src/gpu/gl/GrGLInterface.cpp
+++ b/src/gpu/gl/GrGLInterface.cpp
@@ -505,5 +505,11 @@ bool GrGLInterface::validate() const {
         }
     }
 
+    if (fExtensions.has("GL_NV_framebuffer_mixed_samples")) {
+        if (NULL == fFunctions.fCoverageModulation) {
+            RETURN_FALSE_INTERFACE
+        }
+    }
+
     return true;
 }