Fix alpha textures in NV ES3 contexts on Windows

src/gpu/gl/GrGpuGL.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrGpuGL.h"
 #include "GrGLNameAllocator.h"
@@ skipping 119 matching lines @@
         const GrGLubyte* version;
         GL_CALL_RET(vendor, GetString(GR_GL_VENDOR));
         GL_CALL_RET(renderer, GetString(GR_GL_RENDERER));
         GL_CALL_RET(version, GetString(GR_GL_VERSION));
         GrPrintf("------------------------- create GrGpuGL %p --------------\n",
                  this);
         GrPrintf("------ VENDOR %s\n", vendor);
         GrPrintf("------ RENDERER %s\n", renderer);
         GrPrintf("------ VERSION %s\n",  version);
         GrPrintf("------ EXTENSIONS\n");
-#if 0  // TODO: Reenable this after GrGLInterface's extensions can be accessed safely.
-       ctx.extensions().print();
-#endif
+        ctx.extensions().print();
         GrPrintf("\n");
         GrPrintf(this->glCaps().dump().c_str());
     }
 
     fProgramCache = SkNEW_ARGS(ProgramCache, (this));
 
     SkASSERT(this->glCaps().maxVertexAttributes() >= GrDrawState::kMaxVertexAttribCnt);
 
     fLastSuccessfulStencilFmtIdx = 0;
     fHWProgramID = 0;
@@ skipping 414 matching lines @@
 
     if (useTexStorage && kGL_GrGLStandard == this->glStandard()) {
         // 565 is not a sized internal format on desktop GL. So on desktop with
         // 565 we always use an unsized internal format to let the system pick
         // the best sized format to convert the 565 data to. Since TexStorage
         // only allows sized internal formats we will instead use TexImage2D.
         useTexStorage = desc.fConfig != kRGB_565_GrPixelConfig;
     }
 
     GrGLenum internalFormat;
-    GrGLenum externalFormat;
-    GrGLenum externalType;
+    GrGLenum externalFormat = 0x0; // suprress warning
+    GrGLenum externalType = 0x0;// suprress warning
+
     // glTexStorage requires sized internal formats on both desktop and ES. ES2 requires an unsized
     // format for glTexImage, unlike ES3 and desktop. However, we allow the driver to decide the
     // size of the internal format whenever possible and so only use a sized internal format when
     // using texture storage.
-    if (!this->configToGLFormats(dataConfig, useTexStorage, &internalFormat,
+    bool useSizedFormat = useTexStorage;
+    // At least some versions of the desktop ES3 drivers for NVIDIA won't accept GL_RED in
+    // glTexImage2D for the internal format but will accept GL_R8.
+    if (!useSizedFormat && kNVIDIA_GrGLVendor == this->glContext().vendor() &&
+        kGLES_GrGLStandard == this->glStandard() && this->glVersion() >= GR_GL_VER(3, 0)) {
+        useSizedFormat = true;
+    }
+    if (!this->configToGLFormats(dataConfig, useSizedFormat, &internalFormat,
                                  &externalFormat, &externalType)) {
         return false;
     }
 
     if (!isNewTexture && GR_GL_PALETTE8_RGBA8 == internalFormat) {
         // paletted textures cannot be updated
         return false;
     }
 
     /*
@@ skipping 2421 matching lines @@
             this->setVertexArrayID(gpu, 0);
         }
         int attrCount = gpu->glCaps().maxVertexAttributes();
         if (fDefaultVertexArrayAttribState.count() != attrCount) {
             fDefaultVertexArrayAttribState.resize(attrCount);
         }
         attribState = &fDefaultVertexArrayAttribState;
     }
     return attribState;
 }