commit dded69693dd3779f081326cde24c3954505b129d
author vbuzinov <vbuzinov@nvidia.com> Fri Jun 12 08:59:45 2015 -0700
committer Commit bot <commit-bot@chromium.org> Fri Jun 12 08:59:45 2015 -0700
tree 0cfc3a16d31093185082268ab16599edb7c0464f
parent 57856a1f589bea64ed84535efed0668221060f9b

Implement support for mixed sampled render targets

Adds a new FBO type kStencil_MSFBOType that is selected whenever
NV_framebuffer_mixed_samples extension is available.  In this new
FBO type a non-msaa color buffer is created with a multisampled
stencil buffer attachment.

Replaces numSamples() with separate numColorSamples and numStencilSamples
methods in RenderTarget.

In mixed samples mode non-MSAA codepaths are used to draw simple shapes,
while NVPR-rendered paths and text are rendered with a multisampled
stencil.

BUG=skia:3177

Review URL: https://codereview.chromium.org/1001503002

src/gpu/gl/GrGLCaps.cpp

diff --git a/src/gpu/gl/GrGLCaps.cpp b/src/gpu/gl/GrGLCaps.cpp
index 40405fd..e8c3b55 100644
--- a/src/gpu/gl/GrGLCaps.cpp
+++ b/src/gpu/gl/GrGLCaps.cpp
@@ -292,6 +292,11 @@
             ctxInfo.hasExtension("GL_NV_sample_mask_override_coverage") &&
             ctxInfo.hasExtension("GL_EXT_raster_multisample");
     }
+    // Workaround NVIDIA bug related to glInvalidateFramebuffer and mixed samples.
+    if (kNVIDIA_GrGLDriver == ctxInfo.driver() && fShaderCaps->mixedSamplesSupport()) {
+        fDiscardRenderTargetSupport = false;
+        fInvalidateFBType = kNone_InvalidateFBType;
+    }
 
     /**************************************************************************
      * GrCaps fields
@@ -789,6 +794,8 @@
             fMSFBOType = kES_EXT_MsToTexture_MSFBOType;
         } else if (ctxInfo.hasExtension("GL_IMG_multisampled_render_to_texture")) {
             fMSFBOType = kES_IMG_MsToTexture_MSFBOType;
+        } else if (fShaderCaps->mixedSamplesSupport() && fShaderCaps->pathRenderingSupport()) {
+            fMSFBOType = kMixedSamples_MSFBOType;
         } else if (ctxInfo.version() >= GR_GL_VER(3,0)) {
             fMSFBOType = GrGLCaps::kES_3_0_MSFBOType;
         } else if (ctxInfo.hasExtension("GL_CHROMIUM_framebuffer_multisample")) {
@@ -799,7 +806,9 @@
             fMSFBOType = kES_Apple_MSFBOType;
         }
     } else {
-        if ((ctxInfo.version() >= GR_GL_VER(3,0)) ||
+        if (fShaderCaps->mixedSamplesSupport() && fShaderCaps->pathRenderingSupport()) {
+            fMSFBOType = kMixedSamples_MSFBOType;
+        } else if ((ctxInfo.version() >= GR_GL_VER(3,0)) ||
             ctxInfo.hasExtension("GL_ARB_framebuffer_object")) {
             fMSFBOType = GrGLCaps::kDesktop_ARB_MSFBOType;
         } else if (ctxInfo.hasExtension("GL_EXT_framebuffer_multisample") &&
@@ -932,6 +941,7 @@
         "Apple",
         "IMG MS To Texture",
         "EXT MS To Texture",
+        "MixedSamples",
     };
     GR_STATIC_ASSERT(0 == kNone_MSFBOType);
     GR_STATIC_ASSERT(1 == kDesktop_ARB_MSFBOType);
@@ -940,6 +950,7 @@
     GR_STATIC_ASSERT(4 == kES_Apple_MSFBOType);
     GR_STATIC_ASSERT(5 == kES_IMG_MsToTexture_MSFBOType);
     GR_STATIC_ASSERT(6 == kES_EXT_MsToTexture_MSFBOType);
+    GR_STATIC_ASSERT(7 == kMixedSamples_MSFBOType);
     GR_STATIC_ASSERT(SK_ARRAY_COUNT(kMSFBOExtStr) == kLast_MSFBOType + 1);
 
     static const char* kInvalidateFBTypeStr[] = {