Use glGetStringi to get extensions when available.

include/gpu/gl/SkGLContext.h

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #ifndef SkGLContext_DEFINED
 #define SkGLContext_DEFINED
 
+#include "GrGLExtensions.h"
 #include "GrGLInterface.h"
-#include "SkString.h"
 
 /**
  * Create an offscreen opengl context with an RGBA8 / 8bit stencil FBO.
  * Provides a GrGLInterface struct of function pointers for the context.
  */
 
 class SkGLContext : public SkRefCnt {
 public:
     SK_DECLARE_INST_COUNT(SkGLContext)
 
     SkGLContext();
     virtual ~SkGLContext();
 
     /**
      * Initializes the context and makes it current.
      */
     bool init(const int width, const int height);
 
     int getFBOID() const { return fFBO; }
 
     const GrGLInterface* gl() const { return fGL; }
 
     virtual void makeCurrent() const = 0;
 
-    bool hasExtension(const char* extensionName) const;
+    bool hasExtension(const char* extensionName) const {
+        GrAssert(NULL != fGL);
+        return fExtensions.has(extensionName);
+    }
 
 protected:
     /**
      * Subclass implements this to make a GL context. The returned GrGLInterface
      * should be populated with functions compatible with the context. The
      * format and size of backbuffers does not matter since an FBO will be
      * created.
      */
     virtual const GrGLInterface* createGLContext() = 0;
 
     /**
      * Subclass should destroy the underlying GL context.
      */
     virtual void destroyGLContext() = 0;
 
 private:
-    SkString fExtensionString;
+    GrGLExtensions fExtensions;
     GrGLuint fFBO;
     GrGLuint fColorBufferID;
     GrGLuint fDepthStencilBufferID;
     const GrGLInterface* fGL;
 
     typedef SkRefCnt INHERITED;
 };
 
 /**
  * Helper macros for using the GL context through the GrGLInterface. Example:
  * SK_GL(glCtx, GenTextures(1, &texID));
  */
 #define SK_GL(ctx, X) (ctx).gl()->f ## X;    \
                       SkASSERT(GR_GL_NO_ERROR == (ctx).gl()->fGetError())
 #define SK_GL_RET(ctx, RET, X) (RET) = (ctx).gl()->f ## X;    \
                   SkASSERT(GR_GL_NO_ERROR == (ctx).gl()->fGetError())
 #define SK_GL_NOERRCHECK(ctx, X) (ctx).gl()->f ## X
 #define SK_GL_RET_NOERRCHECK(ctx, RET, X) (RET) = (ctx).gl()->f ## X
 
 #endif