Implement support for mixed sampled render targets

src/gpu/gl/GrGLCaps.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrGLCaps.h"
 
@@ skipping 682 matching lines @@
 void GrGLCaps::initFSAASupport(const GrGLContextInfo& ctxInfo, const GrGLInterface* gli) {
 
     fMSFBOType = kNone_MSFBOType;
     if (kGL_GrGLStandard != ctxInfo.standard()) {
         // We prefer the EXT/IMG extension over ES3 MSAA because we've observed
         // ES3 driver bugs on at least one device with a tiled GPU (N10).
         if (ctxInfo.hasExtension("GL_EXT_multisampled_render_to_texture")) {
             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()) {

[vbuzinov, 2015/06/10 11:23:27]

Currently crashes here due to uninitialized fShaderCaps

[bsalomon, 2015/06/10 19:57:07]

Is it possible to just make the shader caps be initialized first?


At a higher level, is it wrong to enable kMixedSamples_MSFBOType without path
rendering?

[Chris Dalton, 2015/06/10 20:55:56]

It's not wrong, just not very useful without path rendering since it's the only
thing that even knows how to use mixed samples at the moment.

+            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")) {
             // chrome's extension is equivalent to the EXT msaa
             // and fbo_blit extensions.
             fMSFBOType = kDesktop_EXT_MSFBOType;
         } else if (ctxInfo.hasExtension("GL_APPLE_framebuffer_multisample")) {
             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") &&
                    ctxInfo.hasExtension("GL_EXT_framebuffer_blit")) {
             fMSFBOType = GrGLCaps::kDesktop_EXT_MSFBOType;
         }
     }
 }
 
 namespace {
@@ skipping 112 matching lines @@
     }
 
     static const char* kMSFBOExtStr[] = {
         "None",
         "ARB",
         "EXT",
         "ES 3.0",
         "Apple",
         "IMG MS To Texture",
         "EXT MS To Texture",
+        "MixedSamples",
     };
     GR_STATIC_ASSERT(0 == kNone_MSFBOType);
     GR_STATIC_ASSERT(1 == kDesktop_ARB_MSFBOType);
     GR_STATIC_ASSERT(2 == kDesktop_EXT_MSFBOType);
     GR_STATIC_ASSERT(3 == kES_3_0_MSFBOType);
     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[] = {
         "None",
         "Discard",
         "Invalidate",
     };
     GR_STATIC_ASSERT(0 == kNone_InvalidateFBType);
     GR_STATIC_ASSERT(1 == kDiscard_InvalidateFBType);
     GR_STATIC_ASSERT(2 == kInvalidate_InvalidateFBType);
@@ skipping 258 matching lines @@
     if (fGeometryShaderSupport) {
         for (int p = 0; p < kGrSLPrecisionCount; ++p) {
             fFloatPrecisions[kGeometry_GrShaderType][p] = fFloatPrecisions[kVertex_GrShaderType][p];
         }
     }
 }