Enable stencil clipping in 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 337 matching lines @@
         glslCaps->fMixedSamplesSupport =
             ctxInfo.hasExtension("GL_NV_framebuffer_mixed_samples") &&
             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;
     }
+    glslCaps->fProgrammableSampleLocationsSupport = ctxInfo.hasExtension("GL_NV_sample_locations");

[Mark Kilgard, 2015/09/30 17:17:47]

probably also worth looking for ARB_sample_locations extension name here.

NVIDIA products will support both the NV (predated the ARB version) and, in
newer versions, the ARB version.

Since we currently plan on just toggling the
GL_FRAMEBUFFER_PROGRAMMABLE_SAMPLE_LOCATIONS_ARB FBO state and the ARB and NV
versions have the same token values, I recommend detecting either extension.

So

glslCaps->fProgrammableSampleLocationsSupport =
ctxInfo.hasExtension("GL_NV_sample_locations") ||
ctxInfo.hasExtension("GL_ARB_sample_locations");

+
 
     /**************************************************************************
      * GrCaps fields
      **************************************************************************/
 
     this->initFSAASupport(ctxInfo, gli);
     this->initBlendEqationSupport(ctxInfo);
     this->initStencilFormats(ctxInfo);
 
     if (kGL_GrGLStandard == standard) {
@@ skipping 824 matching lines @@
         for (int p = 0; p < kGrSLPrecisionCount; ++p) {
             glslCaps->fFloatPrecisions[kGeometry_GrShaderType][p] = 
                                                glslCaps->fFloatPrecisions[kVertex_GrShaderType][p];
         }
     }
 }