Move GL-specific include files to their own subdirectory, to better

coexist alongside D3D backend.
Requires gyp change.

http://codereview.appspot.com/5665045/



git-svn-id: http://skia.googlecode.com/svn/trunk@3185 2bbb7eff-a529-9590-31e7-b0007b416f81

8 files changed, 1652 insertions, 0 deletions

diff --git a/include/gpu/gl/GrGLConfig.h b/include/gpu/gl/GrGLConfig.h
new file mode 100644
index 0000000000..5ae931c607
--- /dev/null
+++ b/include/gpu/gl/GrGLConfig.h
@@ -0,0 +1,273 @@
+
+/*
+ * 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 GrGLConfig_DEFINED
+#define GrGLConfig_DEFINED
+
+#include "GrTypes.h"
+#include "GrGLDefines.h"
+
+/**
+ * Optional GL config file.
+ */
+#ifdef GR_GL_CUSTOM_SETUP_HEADER
+    #include GR_GL_CUSTOM_SETUP_HEADER
+#endif
+
+#if !defined(GR_GL_FUNCTION_TYPE)
+    #define GR_GL_FUNCTION_TYPE
+#endif
+
+/**
+ * The following are optional defines that can be enabled at the compiler
+ * command line, in a IDE project, in a GrUserConfig.h file, or in a GL custom
+ * file (if one is in use). If a GR_GL_CUSTOM_SETUP_HEADER is used they can
+ * also be placed there.
+ *
+ * GR_GL_LOG_CALLS: if 1 Gr can print every GL call using GrPrintf. Defaults to
+ * 0. Logging can be enabled and disabled at runtime using a debugger via to
+ * global gLogCallsGL. The initial value of gLogCallsGL is controlled by
+ * GR_GL_LOG_CALLS_START.
+ *
+ * GR_GL_LOG_CALLS_START: controls the initial value of gLogCallsGL when
+ * GR_GL_LOG_CALLS is 1. Defaults to 0.
+ *
+ * GR_GL_CHECK_ERROR: if enabled Gr can do a glGetError() after every GL call.
+ * Defaults to 1 if GR_DEBUG is set, otherwise 0. When GR_GL_CHECK_ERROR is 1
+ * this can be toggled in a debugger using the gCheckErrorGL global. The initial
+ * value of gCheckErrorGL is controlled by by GR_GL_CHECK_ERROR_START.
+ *
+ * GR_GL_CHECK_ERROR_START: controls the initial value of gCheckErrorGL
+ * when GR_GL_CHECK_ERROR is 1.  Defaults to 1.
+ *
+ * GR_GL_NO_CONSTANT_ATTRIBUTES: if this evaluates to true then the GL backend
+ * will use uniforms instead of attributes in all cases when there is not
+ * per-vertex data. This is important when the underlying GL implementation
+ * doesn't actually support immediate style attribute values (e.g. when 
+ * the GL stream is converted to DX as in ANGLE on Chrome). Defaults to 0.
+ *
+ * GR_GL_ATTRIBUTE_MATRICES: If changing uniforms is very expensive it may be
+ * faster to use vertex attributes for matrices (set via glVertexAttrib3fv). 
+ * Setting this build flag enables this behavior. GR_GL_NO_CONSTANT_ATTRIBUTES
+ * must not be set since this uses constant attributes for the matrices. 
+ * Defaults to 0.
+ *
+ * GR_GL_USE_BUFFER_DATA_NULL_HINT: When specifing new data for a vertex/index
+ * buffer that replaces old data Ganesh can give a hint to the driver that the
+ * previous data will not be used in future draws like this:
+ *  glBufferData(GL_..._BUFFER, size, NULL, usage);       //<--hint, NULL means
+ *  glBufferSubData(GL_..._BUFFER, 0, lessThanSize, data) //   old data can't be
+ *                                                        //   used again.
+ * However, this can be an unoptimization on some platforms, esp. Chrome.
+ * Chrome's cmd buffer will create a new allocation and memset the whole thing
+ * to zero (for security reasons). Defaults to 1 (enabled).
+ *
+ * GR_GL_PER_GL_FUNC_CALLBACK: When set to 1 the GrGLInterface object provides
+ * a function pointer that is called just before every gl function. The ptr must
+ * be valid (i.e. there is no NULL check). However, by default the callback will
+ * be set to a function that does nothing. The signature of the function is:
+ *    void function(const GrGLInterface*)
+ * It is not extern "C".
+ * The GrGLInterface field fCallback specifies the function ptr and there is an
+ * additional field fCallbackData of type intptr_t for client data.
+ *
+ * GR_GL_RGBA_8888_PIXEL_OPS_SLOW: Set this to 1 if it is known that performing
+ * glReadPixels / glTex(Sub)Image with format=GL_RGBA, type=GL_UNISIGNED_BYTE is
+ * significantly slower than format=GL_BGRA, type=GL_UNISIGNED_BYTE.
+ *
+ * GR_GL_FULL_READPIXELS_FASTER_THAN_PARTIAL: Set this to 1 if calling
+ * glReadPixels to read the entire framebuffer is faster than calling it with
+ * the same sized rectangle but with a framebuffer bound that is larger than
+ * the rectangle read.
+ *
+ * GR_GL_CHECK_ALLOC_WITH_GET_ERROR: If set to 1 this will then glTexImage,
+ * glBufferData, glRenderbufferStorage, etc will be checked for errors. This
+ * amounts to ensuring the error is GL_NO_ERROR, calling the allocating
+ * function, and then checking that the error is still GL_NO_ERROR. When the
+ * value is 0 we will assume no error was generated without checking.
+ *
+ * GR_GL_CHECK_FBO_STATUS_ONCE_PER_FORMAT: We will normally check the FBO status
+ * every time we bind a texture or renderbuffer to an FBO. However, in some
+ * environments CheckFrameBufferStatus is very expensive. If this is set we will
+ * check the first time we use a color format or a combination of color /
+ * stencil formats as attachments. If the FBO is complete we will assume
+ * subsequent attachments with the same formats are complete as well.
+ */
+
+#if !defined(GR_GL_LOG_CALLS)
+    #define GR_GL_LOG_CALLS                             GR_DEBUG
+#endif
+
+#if !defined(GR_GL_LOG_CALLS_START)
+    #define GR_GL_LOG_CALLS_START                       0
+#endif
+
+#if !defined(GR_GL_CHECK_ERROR)
+    #define GR_GL_CHECK_ERROR                           GR_DEBUG
+#endif
+
+#if !defined(GR_GL_CHECK_ERROR_START)
+    #define GR_GL_CHECK_ERROR_START                     1
+#endif
+
+#if !defined(GR_GL_NO_CONSTANT_ATTRIBUTES)
+    #define GR_GL_NO_CONSTANT_ATTRIBUTES                0
+#endif
+
+#if !defined(GR_GL_ATTRIBUTE_MATRICES)
+    #define GR_GL_ATTRIBUTE_MATRICES                    0
+#endif
+
+#if !defined(GR_GL_USE_BUFFER_DATA_NULL_HINT)
+    #define GR_GL_USE_BUFFER_DATA_NULL_HINT             1
+#endif
+
+#if !defined(GR_GL_PER_GL_FUNC_CALLBACK)
+    #define GR_GL_PER_GL_FUNC_CALLBACK                  0
+#endif
+
+#if !defined(GR_GL_RGBA_8888_PIXEL_OPS_SLOW)
+    #define GR_GL_RGBA_8888_PIXEL_OPS_SLOW              0
+#endif
+
+#if !defined(GR_GL_FULL_READPIXELS_FASTER_THAN_PARTIAL)
+    #define GR_GL_FULL_READPIXELS_FASTER_THAN_PARTIAL   0
+#endif
+
+#if !defined(GR_GL_CHECK_ALLOC_WITH_GET_ERROR)
+    #define GR_GL_CHECK_ALLOC_WITH_GET_ERROR            1
+#endif
+
+#if !defined(GR_GL_CHECK_FBO_STATUS_ONCE_PER_FORMAT)
+    #define GR_GL_CHECK_FBO_STATUS_ONCE_PER_FORMAT      0
+#endif
+
+#if(GR_GL_NO_CONSTANT_ATTRIBUTES) && (GR_GL_ATTRIBUTE_MATRICES)
+    #error "Cannot combine GR_GL_NO_CONSTANT_ATTRIBUTES and GR_GL_ATTRIBUTE_MATRICES"
+#endif
+
+////////////////////////////////////////////////////////////////////////////////
+
+#if GR_SCALAR_IS_FIXED
+    #define GrGLType   GL_FIXED
+#elif GR_SCALAR_IS_FLOAT
+    #define GrGLType   GR_GL_FLOAT
+#else
+    #error "unknown GR_SCALAR type"
+#endif
+
+#if GR_TEXT_SCALAR_IS_USHORT
+    #define GrGLTextType                    GR_GL_UNSIGNED_SHORT
+    #define GR_GL_TEXT_TEXTURE_NORMALIZED   1
+#elif GR_TEXT_SCALAR_IS_FLOAT
+    #define GrGLTextType                    GR_GL_FLOAT
+    #define GR_GL_TEXT_TEXTURE_NORMALIZED   0
+#elif GR_TEXT_SCALAR_IS_FIXED
+    #define GrGLTextType                    GR_GL_FIXED
+    #define GR_GL_TEXT_TEXTURE_NORMALIZED   0
+#else
+    #error "unknown GR_TEXT_SCALAR type"
+#endif
+
+////////////////////////////////////////////////////////////////////////////////
+
+struct GrGLInterface;
+
+extern void GrGLCheckErr(const GrGLInterface* gl,
+                         const char* location,
+                         const char* call);
+
+extern void GrGLClearErr(const GrGLInterface* gl);
+
+#if GR_GL_CHECK_ERROR
+    extern bool gCheckErrorGL;
+    #define GR_GL_CHECK_ERROR_IMPL(IFACE, X)                    \
+        if (gCheckErrorGL)                                      \
+            GrGLCheckErr(IFACE, GR_FILE_AND_LINE_STR, #X)
+#else
+    #define GR_GL_CHECK_ERROR_IMPL(IFACE, X)
+#endif
+
+#if GR_GL_LOG_CALLS
+    extern bool gLogCallsGL;
+    #define GR_GL_LOG_CALLS_IMPL(X)                             \
+        if (gLogCallsGL)                                        \
+            GrPrintf(GR_FILE_AND_LINE_STR "GL: " #X "\n")
+#else
+    #define GR_GL_LOG_CALLS_IMPL(X)
+#endif
+
+#if GR_GL_PER_GL_FUNC_CALLBACK
+    #define GR_GL_CALLBACK_IMPL(IFACE) (IFACE)->fCallback(IFACE)
+#else
+    #define GR_GL_CALLBACK_IMPL(IFACE)
+#endif
+
+#define GR_GL_CALL(IFACE, X)                                    \
+    do {                                                        \
+        GR_GL_CALL_NOERRCHECK(IFACE, X);                        \
+        GR_GL_CHECK_ERROR_IMPL(IFACE, X);                       \
+    } while (false)
+
+#define GR_GL_CALL_NOERRCHECK(IFACE, X)                         \
+    do {                                                        \
+        GR_GL_CALLBACK_IMPL(IFACE);                             \
+        (IFACE)->f##X;                                          \
+        GR_GL_LOG_CALLS_IMPL(X);                                \
+    } while (false)
+
+#define GR_GL_CALL_RET(IFACE, RET, X)                           \
+    do {                                                        \
+        GR_GL_CALL_RET_NOERRCHECK(IFACE, RET, X);               \
+        GR_GL_CHECK_ERROR_IMPL(IFACE, X);                       \
+    } while (false)
+
+#define GR_GL_CALL_RET_NOERRCHECK(IFACE, RET, X)                \
+    do {                                                        \
+        GR_GL_CALLBACK_IMPL(IFACE);                             \
+        (RET) = (IFACE)->f##X;                                  \
+        GR_GL_LOG_CALLS_IMPL(X);                                \
+    } while (false)
+
+#define GR_GL_GET_ERROR(IFACE) (IFACE)->fGetError()
+
+////////////////////////////////////////////////////////////////////////////////
+
+/**
+ *  Some drivers want the var-int arg to be zero-initialized on input.
+ */
+#define GR_GL_INIT_ZERO     0
+#define GR_GL_GetIntegerv(gl, e, p)     \
+    do {                            \
+        *(p) = GR_GL_INIT_ZERO;     \
+        GR_GL_CALL(gl, GetIntegerv(e, p));   \
+    } while (0)
+
+#define GR_GL_GetFramebufferAttachmentParameteriv(gl, t, a, pname, p)           \
+    do {                                                                        \
+        *(p) = GR_GL_INIT_ZERO;                                                 \
+        GR_GL_CALL(gl, GetFramebufferAttachmentParameteriv(t, a, pname, p));    \
+    } while (0)
+
+#define GR_GL_GetRenderbufferParameteriv(gl, t, pname, p)                       \
+    do {                                                                        \
+        *(p) = GR_GL_INIT_ZERO;                                                 \
+        GR_GL_CALL(gl, GetRenderbufferParameteriv(t, pname, p));                \
+    } while (0)
+
+#define GR_GL_GetTexLevelParameteriv(gl, t, l, pname, p)                        \
+    do {                                                                        \
+        *(p) = GR_GL_INIT_ZERO;                                                 \
+        GR_GL_CALL(gl, GetTexLevelParameteriv(t, l, pname, p));                 \
+    } while (0)
+
+////////////////////////////////////////////////////////////////////////////////
+
+#endif
diff --git a/include/gpu/gl/GrGLConfig_chrome.h b/include/gpu/gl/GrGLConfig_chrome.h
new file mode 100644
index 0000000000..50ea34c6d3
--- /dev/null
+++ b/include/gpu/gl/GrGLConfig_chrome.h
@@ -0,0 +1,37 @@
+
+/*
+ * 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 GrGLConfig_chrome_DEFINED
+#define GrGLConfig_chrome_DEFINED
+
+// glGetError() forces a sync with gpu process on chrome
+#define GR_GL_CHECK_ERROR_START                     0
+
+// ANGLE creates a temp VB for vertex attributes not specified per-vertex.
+#define GR_GL_NO_CONSTANT_ATTRIBUTES                GR_WIN32_BUILD
+
+// For RGBA teximage/readpixels ANGLE will sw-convert to/from BGRA.
+#define GR_GL_RGBA_8888_PIXEL_OPS_SLOW              GR_WIN32_BUILD
+
+// ANGLE can go faster if the entire fbo is read rather than a subrect
+#define GR_GL_FULL_READPIXELS_FASTER_THAN_PARTIAL   GR_WIN32_BUILD
+
+// cmd buffer allocates memory and memsets it to zero when it sees glBufferData
+// with NULL.
+#define GR_GL_USE_BUFFER_DATA_NULL_HINT             0
+
+// chrome uses this to set the context on each GL call.
+#define GR_GL_PER_GL_FUNC_CALLBACK                  1
+
+// Check error is even more expensive in chrome (cmd buffer flush). The
+// compositor also doesn't check its allocations.
+#define GR_GL_CHECK_ALLOC_WITH_GET_ERROR            0
+
+// CheckFramebufferStatus in chrome synchronizes the gpu and renderer processes.
+#define GR_GL_CHECK_FBO_STATUS_ONCE_PER_FORMAT      1
+
+#endif
diff --git a/include/gpu/gl/GrGLDefines.h b/include/gpu/gl/GrGLDefines.h
new file mode 100644
index 0000000000..e66eec4edf
--- /dev/null
+++ b/include/gpu/gl/GrGLDefines.h
@@ -0,0 +1,692 @@
+
+/*
+ * 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 GrGLDefines_DEFINED
+#define GrGLDefines_DEFINED
+
+// The following constants consist of the intersection of GL constants
+// exported by GLES 1.0, GLES 2.0, and desktop GL required by the system.
+
+#define GR_GL_DEPTH_BUFFER_BIT               0x00000100
+#define GR_GL_STENCIL_BUFFER_BIT             0x00000400
+#define GR_GL_COLOR_BUFFER_BIT               0x00004000
+
+/* Boolean */
+#define GR_GL_FALSE                          0
+#define GR_GL_TRUE                           1
+
+/* BeginMode */
+#define GR_GL_POINTS                         0x0000
+#define GR_GL_LINES                          0x0001
+#define GR_GL_LINE_LOOP                      0x0002
+#define GR_GL_LINE_STRIP                     0x0003
+#define GR_GL_TRIANGLES                      0x0004
+#define GR_GL_TRIANGLE_STRIP                 0x0005
+#define GR_GL_TRIANGLE_FAN                   0x0006
+
+/* AlphaFunction (not supported in ES20) */
+/*      GL_NEVER */
+/*      GL_LESS */
+/*      GL_EQUAL */
+/*      GL_LEQUAL */
+/*      GL_GREATER */
+/*      GL_NOTEQUAL */
+/*      GL_GEQUAL */
+/*      GL_ALWAYS */
+
+/* BlendingFactorDest */
+#define GR_GL_ZERO                           0
+#define GR_GL_ONE                            1
+#define GR_GL_SRC_COLOR                      0x0300
+#define GR_GL_ONE_MINUS_SRC_COLOR            0x0301
+#define GR_GL_SRC_ALPHA                      0x0302
+#define GR_GL_ONE_MINUS_SRC_ALPHA            0x0303
+#define GR_GL_DST_ALPHA                      0x0304
+#define GR_GL_ONE_MINUS_DST_ALPHA            0x0305
+
+/* BlendingFactorSrc */
+/*      GL_ZERO */
+/*      GL_ONE */
+#define GR_GL_DST_COLOR                      0x0306
+#define GR_GL_ONE_MINUS_DST_COLOR            0x0307
+#define GR_GL_SRC_ALPHA_SATURATE             0x0308
+/*      GL_SRC_ALPHA */
+/*      GL_ONE_MINUS_SRC_ALPHA */
+/*      GL_DST_ALPHA */
+/*      GL_ONE_MINUS_DST_ALPHA */
+
+/* ExtendedBlendFactors */
+#define GR_GL_SRC1_COLOR                     0x88F9
+#define GR_GL_ONE_MINUS_SRC1_COLOR           0x88FA
+/*      GL_SRC1_ALPHA */
+#define GR_GL_ONE_MINUS_SRC1_ALPHA           0x88FB
+
+/* BlendEquationSeparate */
+#define GR_GL_FUNC_ADD                       0x8006
+#define GR_GL_BLEND_EQUATION                 0x8009
+#define GR_GL_BLEND_EQUATION_RGB             0x8009    /* same as BLEND_EQUATION */
+#define GR_GL_BLEND_EQUATION_ALPHA           0x883D
+
+/* BlendSubtract */
+#define GR_GL_FUNC_SUBTRACT                  0x800A
+#define GR_GL_FUNC_REVERSE_SUBTRACT          0x800B
+
+/* Separate Blend Functions */
+#define GR_GL_BLEND_DST_RGB                  0x80C8
+#define GR_GL_BLEND_SRC_RGB                  0x80C9
+#define GR_GL_BLEND_DST_ALPHA                0x80CA
+#define GR_GL_BLEND_SRC_ALPHA                0x80CB
+#define GR_GL_CONSTANT_COLOR                 0x8001
+#define GR_GL_ONE_MINUS_CONSTANT_COLOR       0x8002
+#define GR_GL_CONSTANT_ALPHA                 0x8003
+#define GR_GL_ONE_MINUS_CONSTANT_ALPHA       0x8004
+#define GR_GL_BLEND_COLOR                    0x8005
+
+/* Buffer Objects */
+#define GR_GL_ARRAY_BUFFER                   0x8892
+#define GR_GL_ELEMENT_ARRAY_BUFFER           0x8893
+#define GR_GL_ARRAY_BUFFER_BINDING           0x8894
+#define GR_GL_ELEMENT_ARRAY_BUFFER_BINDING   0x8895
+
+#define GR_GL_STREAM_DRAW                    0x88E0
+#define GR_GL_STATIC_DRAW                    0x88E4
+#define GR_GL_DYNAMIC_DRAW                   0x88E8
+
+#define GR_GL_BUFFER_SIZE                    0x8764
+#define GR_GL_BUFFER_USAGE                   0x8765
+
+#define GR_GL_CURRENT_VERTEX_ATTRIB          0x8626
+
+/* CullFaceMode */
+#define GR_GL_FRONT                          0x0404
+#define GR_GL_BACK                           0x0405
+#define GR_GL_FRONT_AND_BACK                 0x0408
+
+/* DepthFunction */
+/*      GL_NEVER */
+/*      GL_LESS */
+/*      GL_EQUAL */
+/*      GL_LEQUAL */
+/*      GL_GREATER */
+/*      GL_NOTEQUAL */
+/*      GL_GEQUAL */
+/*      GL_ALWAYS */
+
+/* EnableCap */
+#define GR_GL_TEXTURE_2D                     0x0DE1
+#define GR_GL_CULL_FACE                      0x0B44
+#define GR_GL_BLEND                          0x0BE2
+#define GR_GL_DITHER                         0x0BD0
+#define GR_GL_STENCIL_TEST                   0x0B90
+#define GR_GL_DEPTH_TEST                     0x0B71
+#define GR_GL_SCISSOR_TEST                   0x0C11
+#define GR_GL_POLYGON_OFFSET_FILL            0x8037
+#define GR_GL_SAMPLE_ALPHA_TO_COVERAGE       0x809E
+#define GR_GL_SAMPLE_COVERAGE                0x80A0
+
+/* ErrorCode */
+#define GR_GL_NO_ERROR                       0
+#define GR_GL_INVALID_ENUM                   0x0500
+#define GR_GL_INVALID_VALUE                  0x0501
+#define GR_GL_INVALID_OPERATION              0x0502
+#define GR_GL_OUT_OF_MEMORY                  0x0505
+#define GR_GL_CONTEXT_LOST                   0x300E  // TODO(gman): What value?
+
+/* FrontFaceDirection */
+#define GR_GL_CW                             0x0900
+#define GR_GL_CCW                            0x0901
+
+/* GetPName */
+#define GR_GL_LINE_WIDTH                     0x0B21
+#define GR_GL_ALIASED_POINT_SIZE_RANGE       0x846D
+#define GR_GL_ALIASED_LINE_WIDTH_RANGE       0x846E
+#define GR_GL_CULL_FACE_MODE                 0x0B45
+#define GR_GL_FRONT_FACE                     0x0B46
+#define GR_GL_DEPTH_RANGE                    0x0B70
+#define GR_GL_DEPTH_WRITEMASK                0x0B72
+#define GR_GL_DEPTH_CLEAR_VALUE              0x0B73
+#define GR_GL_DEPTH_FUNC                     0x0B74
+#define GR_GL_STENCIL_CLEAR_VALUE            0x0B91
+#define GR_GL_STENCIL_FUNC                   0x0B92
+#define GR_GL_STENCIL_FAIL                   0x0B94
+#define GR_GL_STENCIL_PASS_DEPTH_FAIL        0x0B95
+#define GR_GL_STENCIL_PASS_DEPTH_PASS        0x0B96
+#define GR_GL_STENCIL_REF                    0x0B97
+#define GR_GL_STENCIL_VALUE_MASK             0x0B93
+#define GR_GL_STENCIL_WRITEMASK              0x0B98
+#define GR_GL_STENCIL_BACK_FUNC              0x8800
+#define GR_GL_STENCIL_BACK_FAIL              0x8801
+#define GR_GL_STENCIL_BACK_PASS_DEPTH_FAIL   0x8802
+#define GR_GL_STENCIL_BACK_PASS_DEPTH_PASS   0x8803
+#define GR_GL_STENCIL_BACK_REF               0x8CA3
+#define GR_GL_STENCIL_BACK_VALUE_MASK        0x8CA4
+#define GR_GL_STENCIL_BACK_WRITEMASK         0x8CA5
+#define GR_GL_VIEWPORT                       0x0BA2
+#define GR_GL_SCISSOR_BOX                    0x0C10
+/*      GL_SCISSOR_TEST */
+#define GR_GL_COLOR_CLEAR_VALUE              0x0C22
+#define GR_GL_COLOR_WRITEMASK                0x0C23
+#define GR_GL_UNPACK_ALIGNMENT               0x0CF5
+#define GR_GL_UNPACK_FLIP_Y                  0x9240
+#define GR_GL_PACK_ALIGNMENT                 0x0D05
+#define GR_GL_PACK_REVERSE_ROW_ORDER         0x93A4
+#define GR_GL_MAX_TEXTURE_SIZE               0x0D33
+#define GR_GL_MAX_VIEWPORT_DIMS              0x0D3A
+#define GR_GL_SUBPIXEL_BITS                  0x0D50
+#define GR_GL_RED_BITS                       0x0D52
+#define GR_GL_GREEN_BITS                     0x0D53
+#define GR_GL_BLUE_BITS                      0x0D54
+#define GR_GL_ALPHA_BITS                     0x0D55
+#define GR_GL_DEPTH_BITS                     0x0D56
+#define GR_GL_STENCIL_BITS                   0x0D57
+#define GR_GL_POLYGON_OFFSET_UNITS           0x2A00
+/*      GL_POLYGON_OFFSET_FILL */
+#define GR_GL_POLYGON_OFFSET_FACTOR          0x8038
+#define GR_GL_TEXTURE_BINDING_2D             0x8069
+#define GR_GL_SAMPLE_BUFFERS                 0x80A8
+#define GR_GL_SAMPLES                        0x80A9
+#define GR_GL_SAMPLE_COVERAGE_VALUE          0x80AA
+#define GR_GL_SAMPLE_COVERAGE_INVERT         0x80AB
+
+/* GetTextureParameter */
+/*      GL_TEXTURE_MAG_FILTER */
+/*      GL_TEXTURE_MIN_FILTER */
+/*      GL_TEXTURE_WRAP_S */
+/*      GL_TEXTURE_WRAP_T */
+
+#define GR_GL_NUM_COMPRESSED_TEXTURE_FORMATS 0x86A2
+#define GR_GL_COMPRESSED_TEXTURE_FORMATS     0x86A3
+
+/* HintMode */
+#define GR_GL_DONT_CARE                      0x1100
+#define GR_GL_FASTEST                        0x1101
+#define GR_GL_NICEST                         0x1102
+
+/* HintTarget */
+#define GR_GL_GENERATE_MIPMAP_HINT            0x8192
+
+/* DataType */
+#define GR_GL_BYTE                           0x1400
+#define GR_GL_UNSIGNED_BYTE                  0x1401
+#define GR_GL_SHORT                          0x1402
+#define GR_GL_UNSIGNED_SHORT                 0x1403
+#define GR_GL_INT                            0x1404
+#define GR_GL_UNSIGNED_INT                   0x1405
+#define GR_GL_FLOAT                          0x1406
+#define GR_GL_FIXED                          0x140C
+
+/* Lighting */
+#define GR_GL_LIGHTING                       0x0B50
+#define GR_GL_LIGHT0                         0x4000
+#define GR_GL_LIGHT1                         0x4001
+#define GR_GL_LIGHT2                         0x4002
+#define GR_GL_LIGHT3                         0x4003
+#define GR_GL_LIGHT4                         0x4004
+#define GR_GL_LIGHT5                         0x4005
+#define GR_GL_LIGHT6                         0x4006
+#define GR_GL_LIGHT7                         0x4007
+#define GR_GL_SPOT_EXPONENT                  0x1205
+#define GR_GL_SPOT_CUTOFF                    0x1206
+#define GR_GL_CONSTANT_ATTENUATION           0x1207
+#define GR_GL_LINEAR_ATTENUATION             0x1208
+#define GR_GL_QUADRATIC_ATTENUATION          0x1209
+#define GR_GL_AMBIENT                        0x1200
+#define GR_GL_DIFFUSE                        0x1201
+#define GR_GL_SPECULAR                       0x1202
+#define GR_GL_SHININESS                      0x1601
+#define GR_GL_EMISSION                       0x1600
+#define GR_GL_POSITION                       0x1203
+#define GR_GL_SPOT_DIRECTION                 0x1204
+#define GR_GL_AMBIENT_AND_DIFFUSE            0x1602
+#define GR_GL_COLOR_INDEXES                  0x1603
+#define GR_GL_LIGHT_MODEL_TWO_SIDE           0x0B52
+#define GR_GL_LIGHT_MODEL_LOCAL_VIEWER       0x0B51
+#define GR_GL_LIGHT_MODEL_AMBIENT            0x0B53
+#define GR_GL_FRONT_AND_BACK                 0x0408
+#define GR_GL_SHADE_MODEL                    0x0B54
+#define GR_GL_FLAT                           0x1D00
+#define GR_GL_SMOOTH                         0x1D01
+#define GR_GL_COLOR_MATERIAL                 0x0B57
+#define GR_GL_COLOR_MATERIAL_FACE            0x0B55
+#define GR_GL_COLOR_MATERIAL_PARAMETER       0x0B56
+#define GR_GL_NORMALIZE                      0x0BA1
+
+/* Matrix Mode */
+#define GR_GL_MATRIX_MODE                    0x0BA0
+#define GR_GL_MODELVIEW                      0x1700
+#define GR_GL_PROJECTION                     0x1701
+#define GR_GL_TEXTURE                        0x1702
+
+/* multisample */
+#define GR_GL_MULTISAMPLE                    0x809D
+
+/* Points */
+#define GR_GL_POINT_SMOOTH                   0x0B10
+#define GR_GL_POINT_SIZE                     0x0B11
+#define GR_GL_POINT_SIZE_GRANULARITY         0x0B13
+#define GR_GL_POINT_SIZE_RANGE               0x0B12
+
+/* Lines */
+#define GR_GL_LINE_SMOOTH                    0x0B20
+#define GR_GL_LINE_STIPPLE                   0x0B24
+#define GR_GL_LINE_STIPPLE_PATTERN           0x0B25
+#define GR_GL_LINE_STIPPLE_REPEAT            0x0B26
+#define GR_GL_LINE_WIDTH                     0x0B21
+#define GR_GL_LINE_WIDTH_GRANULARITY         0x0B23
+#define GR_GL_LINE_WIDTH_RANGE               0x0B22
+
+/* PixelFormat */
+#define GR_GL_DEPTH_COMPONENT                0x1902
+#define GR_GL_RED                            0x1903
+#define GR_GL_GREEN                          0x1904
+#define GR_GL_BLUE                           0x1905
+#define GR_GL_ALPHA                          0x1906
+#define GR_GL_RGB                            0x1907
+#define GR_GL_RGBA                           0x1908
+#define GR_GL_BGRA                           0x80E1
+#define GR_GL_LUMINANCE                      0x1909
+#define GR_GL_LUMINANCE_ALPHA                0x190A
+#define GR_GL_PALETTE8_RGBA8                 0x8B96
+#define GR_GL_ALPHA8                         0x803C
+
+/* PixelType */
+/*      GL_UNSIGNED_BYTE */
+#define GR_GL_UNSIGNED_SHORT_4_4_4_4         0x8033
+#define GR_GL_UNSIGNED_SHORT_5_5_5_1         0x8034
+#define GR_GL_UNSIGNED_SHORT_5_6_5           0x8363
+
+/* Shaders */
+#define GR_GL_FRAGMENT_SHADER                  0x8B30
+#define GR_GL_VERTEX_SHADER                    0x8B31
+#define GR_GL_GEOMETRY_SHADER                  0x8DD9
+#define GR_GL_MAX_VERTEX_ATTRIBS               0x8869
+#define GR_GL_MAX_VERTEX_UNIFORM_VECTORS       0x8DFB
+#define GR_GL_MAX_VARYING_VECTORS              0x8DFC
+#define GR_GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS 0x8B4D
+#define GR_GL_MAX_VERTEX_TEXTURE_IMAGE_UNITS   0x8B4C
+#define GR_GL_MAX_TEXTURE_IMAGE_UNITS          0x8872
+#define GR_GL_MAX_FRAGMENT_UNIFORM_VECTORS     0x8DFD
+#define GR_GL_SHADER_TYPE                      0x8B4F
+#define GR_GL_DELETE_STATUS                    0x8B80
+#define GR_GL_LINK_STATUS                      0x8B82
+#define GR_GL_VALIDATE_STATUS                  0x8B83
+#define GR_GL_ATTACHED_SHADERS                 0x8B85
+#define GR_GL_ACTIVE_UNIFORMS                  0x8B86
+#define GR_GL_ACTIVE_UNIFORM_MAX_LENGTH        0x8B87
+#define GR_GL_ACTIVE_ATTRIBUTES                0x8B89
+#define GR_GL_ACTIVE_ATTRIBUTE_MAX_LENGTH      0x8B8A
+#define GR_GL_SHADING_LANGUAGE_VERSION         0x8B8C
+#define GR_GL_CURRENT_PROGRAM                  0x8B8D
+#define GR_GL_MAX_FRAGMENT_UNIFORM_COMPONENTS  0x8B49
+#define GR_GL_MAX_VERTEX_UNIFORM_COMPONENTS    0x8B4A
+
+/* StencilFunction */
+#define GR_GL_NEVER                          0x0200
+#define GR_GL_LESS                           0x0201
+#define GR_GL_EQUAL                          0x0202
+#define GR_GL_LEQUAL                         0x0203
+#define GR_GL_GREATER                        0x0204
+#define GR_GL_NOTEQUAL                       0x0205
+#define GR_GL_GEQUAL                         0x0206
+#define GR_GL_ALWAYS                         0x0207
+
+/* StencilOp */
+/*      GL_ZERO */
+#define GR_GL_KEEP                           0x1E00
+#define GR_GL_REPLACE                        0x1E01
+#define GR_GL_INCR                           0x1E02
+#define GR_GL_DECR                           0x1E03
+#define GR_GL_INVERT                         0x150A
+#define GR_GL_INCR_WRAP                      0x8507
+#define GR_GL_DECR_WRAP                      0x8508
+
+/* StringName */
+#define GR_GL_VENDOR                         0x1F00
+#define GR_GL_RENDERER                       0x1F01
+#define GR_GL_VERSION                        0x1F02
+#define GR_GL_EXTENSIONS                     0x1F03
+
+/* Pixel Mode / Transfer */
+#define GR_GL_UNPACK_ROW_LENGTH              0x0CF2
+#define GR_GL_PACK_ROW_LENGTH                0x0D02
+
+
+/* TextureMagFilter */
+#define GR_GL_NEAREST                        0x2600
+#define GR_GL_LINEAR                         0x2601
+
+/* TextureMinFilter */
+/*      GL_NEAREST */
+/*      GL_LINEAR */
+#define GR_GL_NEAREST_MIPMAP_NEAREST         0x2700
+#define GR_GL_LINEAR_MIPMAP_NEAREST          0x2701
+#define GR_GL_NEAREST_MIPMAP_LINEAR          0x2702
+#define GR_GL_LINEAR_MIPMAP_LINEAR           0x2703
+
+/* TextureUsage */
+#define GR_GL_FRAMEBUFFER_ATTACHMENT         0x93A3
+
+/* TextureParameterName */
+#define GR_GL_TEXTURE_MAG_FILTER             0x2800
+#define GR_GL_TEXTURE_MIN_FILTER             0x2801
+#define GR_GL_TEXTURE_WRAP_S                 0x2802
+#define GR_GL_TEXTURE_WRAP_T                 0x2803
+#define GR_GL_TEXTURE_USAGE                  0x93A2
+
+/* TextureTarget */
+/*      GL_TEXTURE_2D */
+#define GR_GL_TEXTURE                        0x1702
+#define GR_GL_TEXTURE_CUBE_MAP               0x8513
+#define GR_GL_TEXTURE_BINDING_CUBE_MAP       0x8514
+#define GR_GL_TEXTURE_CUBE_MAP_POSITIVE_X    0x8515
+#define GR_GL_TEXTURE_CUBE_MAP_NEGATIVE_X    0x8516
+#define GR_GL_TEXTURE_CUBE_MAP_POSITIVE_Y    0x8517
+#define GR_GL_TEXTURE_CUBE_MAP_NEGATIVE_Y    0x8518
+#define GR_GL_TEXTURE_CUBE_MAP_POSITIVE_Z    0x8519
+#define GR_GL_TEXTURE_CUBE_MAP_NEGATIVE_Z    0x851A
+#define GR_GL_MAX_CUBE_MAP_TEXTURE_SIZE      0x851C
+
+/* TextureUnit */
+#define GR_GL_TEXTURE0                       0x84C0
+#define GR_GL_TEXTURE1                       0x84C1
+#define GR_GL_TEXTURE2                       0x84C2
+#define GR_GL_TEXTURE3                       0x84C3
+#define GR_GL_TEXTURE4                       0x84C4
+#define GR_GL_TEXTURE5                       0x84C5
+#define GR_GL_TEXTURE6                       0x84C6
+#define GR_GL_TEXTURE7                       0x84C7
+#define GR_GL_TEXTURE8                       0x84C8
+#define GR_GL_TEXTURE9                       0x84C9
+#define GR_GL_TEXTURE10                      0x84CA
+#define GR_GL_TEXTURE11                      0x84CB
+#define GR_GL_TEXTURE12                      0x84CC
+#define GR_GL_TEXTURE13                      0x84CD
+#define GR_GL_TEXTURE14                      0x84CE
+#define GR_GL_TEXTURE15                      0x84CF
+#define GR_GL_TEXTURE16                      0x84D0
+#define GR_GL_TEXTURE17                      0x84D1
+#define GR_GL_TEXTURE18                      0x84D2
+#define GR_GL_TEXTURE19                      0x84D3
+#define GR_GL_TEXTURE20                      0x84D4
+#define GR_GL_TEXTURE21                      0x84D5
+#define GR_GL_TEXTURE22                      0x84D6
+#define GR_GL_TEXTURE23                      0x84D7
+#define GR_GL_TEXTURE24                      0x84D8
+#define GR_GL_TEXTURE25                      0x84D9
+#define GR_GL_TEXTURE26                      0x84DA
+#define GR_GL_TEXTURE27                      0x84DB
+#define GR_GL_TEXTURE28                      0x84DC
+#define GR_GL_TEXTURE29                      0x84DD
+#define GR_GL_TEXTURE30                      0x84DE
+#define GR_GL_TEXTURE31                      0x84DF
+#define GR_GL_ACTIVE_TEXTURE                 0x84E0
+#define GR_GL_MAX_TEXTURE_UNITS              0x84E2
+
+/* TextureWrapMode */
+#define GR_GL_REPEAT                         0x2901
+#define GR_GL_CLAMP_TO_EDGE                  0x812F
+#define GR_GL_MIRRORED_REPEAT                0x8370
+
+/* Texture Swizzle */
+#define GR_GL_TEXTURE_SWIZZLE_R              0x8E42
+#define GR_GL_TEXTURE_SWIZZLE_G              0x8E43
+#define GR_GL_TEXTURE_SWIZZLE_B              0x8E44
+#define GR_GL_TEXTURE_SWIZZLE_A              0x8E45
+#define GR_GL_TEXTURE_SWIZZLE_RGBA           0x8E46
+
+/* Texture mapping */
+#define GR_GL_TEXTURE_ENV                    0x2300
+#define GR_GL_TEXTURE_ENV_MODE               0x2200
+#define GR_GL_TEXTURE_1D                     0x0DE0
+/* GL_TEXTURE_2D */
+/* GL_TEXTURE_WRAP_S */
+/* GL_TEXTURE_WRAP_T */
+/* GL_TEXTURE_MAG_FILTER */
+/* GL_TEXTURE_MIN_FILTER */
+#define GR_GL_TEXTURE_ENV_COLOR             0x2201
+#define GR_GL_TEXTURE_GEN_S                 0x0C60
+#define GR_GL_TEXTURE_GEN_T                 0x0C61
+#define GR_GL_TEXTURE_GEN_MODE              0x2500
+#define GR_GL_TEXTURE_BORDER_COLOR          0x1004
+#define GR_GL_TEXTURE_WIDTH                 0x1000
+#define GR_GL_TEXTURE_HEIGHT                0x1001
+#define GR_GL_TEXTURE_BORDER                0x1005
+#define GR_GL_TEXTURE_COMPONENTS            0x1003
+#define GR_GL_TEXTURE_RED_SIZE              0x805C
+#define GR_GL_TEXTURE_GREEN_SIZE            0x805D
+#define GR_GL_TEXTURE_BLUE_SIZE             0x805E
+#define GR_GL_TEXTURE_ALPHA_SIZE            0x805F
+#define GR_GL_TEXTURE_LUMINANCE_SIZE        0x8060
+#define GR_GL_TEXTURE_INTENSITY_SIZE        0x8061
+#define GR_GL_TEXTURE_INTERNAL_FORMAT       0x1003
+/* GL_NEAREST_MIPMAP_NEAREST */
+/* GL_NEAREST_MIPMAP_LINEAR */
+/* GL_LINEAR_MIPMAP_NEAREST */
+/* GL_LINEAR_MIPMAP_LINEAR */
+#define GR_GL_OBJECT_LINEAR                 0x2401
+#define GR_GL_OBJECT_PLANE                  0x2501
+#define GR_GL_EYE_LINEAR                    0x2400
+#define GR_GL_EYE_PLANE                     0x2502
+#define GR_GL_SPHERE_MAP                    0x2402
+#define GR_GL_DECAL                         0x2101
+#define GR_GL_MODULATE                      0x2100
+/*	GL_NEAREST */
+/*	GL_REPEAT */
+#define GR_GL_CLAMP                         0x2900
+#define GR_GL_S                             0x2000
+#define GR_GL_T                             0x2001
+#define GR_GL_R                             0x2002
+#define GR_GL_Q                             0x2003
+#define GR_GL_TEXTURE_GEN_R                 0x0C62
+#define GR_GL_TEXTURE_GEN_Q                 0x0C63
+
+/* texture_env_combine */
+#define GR_GL_COMBINE                       0x8570
+#define GR_GL_COMBINE_RGB                   0x8571
+#define GR_GL_COMBINE_ALPHA                 0x8572
+#define GR_GL_SOURCE0_RGB                   0x8580
+#define GR_GL_SOURCE1_RGB                   0x8581
+#define GR_GL_SOURCE2_RGB                   0x8582
+#define GR_GL_SOURCE0_ALPHA                 0x8588
+#define GR_GL_SOURCE1_ALPHA                 0x8589
+#define GR_GL_SOURCE2_ALPHA                 0x858A
+#define GR_GL_OPERAND0_RGB                  0x8590
+#define GR_GL_OPERAND1_RGB                  0x8591
+#define GR_GL_OPERAND2_RGB                  0x8592
+#define GR_GL_OPERAND0_ALPHA                0x8598
+#define GR_GL_OPERAND1_ALPHA                0x8599
+#define GR_GL_OPERAND2_ALPHA                0x859A
+#define GR_GL_RGB_SCALE                     0x8573
+#define GR_GL_ADD_SIGNED                    0x8574
+#define GR_GL_INTERPOLATE                   0x8575
+#define GR_GL_SUBTRACT                      0x84E7
+#define GR_GL_CONSTANT                      0x8576
+#define GR_GL_PRIMARY_COLOR                 0x8577
+#define GR_GL_PREVIOUS                      0x8578
+#define GR_GL_SRC0_RGB                      0x8580
+#define GR_GL_SRC1_RGB                      0x8581
+#define GR_GL_SRC2_RGB                      0x8582
+#define GR_GL_SRC0_ALPHA                    0x8588
+#define GR_GL_SRC1_ALPHA                    0x8589
+#define GR_GL_SRC2_ALPHA                    0x858A
+
+/* Uniform Types */
+#define GR_GL_FLOAT_VEC2                     0x8B50
+#define GR_GL_FLOAT_VEC3                     0x8B51
+#define GR_GL_FLOAT_VEC4                     0x8B52
+#define GR_GL_INT_VEC2                       0x8B53
+#define GR_GL_INT_VEC3                       0x8B54
+#define GR_GL_INT_VEC4                       0x8B55
+#define GR_GL_BOOL                           0x8B56
+#define GR_GL_BOOL_VEC2                      0x8B57
+#define GR_GL_BOOL_VEC3                      0x8B58
+#define GR_GL_BOOL_VEC4                      0x8B59
+#define GR_GL_FLOAT_MAT2                     0x8B5A
+#define GR_GL_FLOAT_MAT3                     0x8B5B
+#define GR_GL_FLOAT_MAT4                     0x8B5C
+#define GR_GL_SAMPLER_2D                     0x8B5E
+#define GR_GL_SAMPLER_CUBE                   0x8B60
+
+/* Vertex Arrays */
+#define GR_GL_VERTEX_ATTRIB_ARRAY_ENABLED        0x8622
+#define GR_GL_VERTEX_ATTRIB_ARRAY_SIZE           0x8623
+#define GR_GL_VERTEX_ATTRIB_ARRAY_STRIDE         0x8624
+#define GR_GL_VERTEX_ATTRIB_ARRAY_TYPE           0x8625
+#define GR_GL_VERTEX_ATTRIB_ARRAY_NORMALIZED     0x886A
+#define GR_GL_VERTEX_ATTRIB_ARRAY_POINTER        0x8645
+#define GR_GL_VERTEX_ATTRIB_ARRAY_BUFFER_BINDING 0x889F
+#define GR_GL_VERTEX_ARRAY                       0x8074
+#define GR_GL_NORMAL_ARRAY                       0x8075
+#define GR_GL_COLOR_ARRAY                        0x8076
+#define GR_GL_INDEX_ARRAY                        0x8077
+#define GR_GL_TEXTURE_COORD_ARRAY                0x8078
+#define GR_GL_EDGE_FLAG_ARRAY                    0x8079
+#define GR_GL_VERTEX_ARRAY_SIZE                  0x807A
+#define GR_GL_VERTEX_ARRAY_TYPE                  0x807B
+#define GR_GL_VERTEX_ARRAY_STRIDE                0x807C
+#define GR_GL_NORMAL_ARRAY_TYPE                  0x807E
+#define GR_GL_NORMAL_ARRAY_STRIDE                0x807F
+#define GR_GL_COLOR_ARRAY_SIZE                   0x8081
+#define GR_GL_COLOR_ARRAY_TYPE                   0x8082
+#define GR_GL_COLOR_ARRAY_STRIDE                 0x8083
+#define GR_GL_INDEX_ARRAY_TYPE                   0x8085
+#define GR_GL_INDEX_ARRAY_STRIDE                 0x8086
+#define GR_GL_TEXTURE_COORD_ARRAY_SIZE           0x8088
+#define GR_GL_TEXTURE_COORD_ARRAY_TYPE           0x8089
+#define GR_GL_TEXTURE_COORD_ARRAY_STRIDE         0x808A
+#define GR_GL_EDGE_FLAG_ARRAY_STRIDE             0x808C
+#define GR_GL_VERTEX_ARRAY_POINTER               0x808E
+#define GR_GL_NORMAL_ARRAY_POINTER               0x808F
+#define GR_GL_COLOR_ARRAY_POINTER                0x8090
+#define GR_GL_INDEX_ARRAY_POINTER                0x8091
+#define GR_GL_TEXTURE_COORD_ARRAY_POINTER        0x8092
+#define GR_GL_EDGE_FLAG_ARRAY_POINTER            0x8093
+#define GR_GL_V2F                                0x2A20
+#define GR_GL_V3F                                0x2A21
+#define GR_GL_C4UB_V2F                           0x2A22
+#define GR_GL_C4UB_V3F                           0x2A23
+#define GR_GL_C3F_V3F                            0x2A24
+#define GR_GL_N3F_V3F                            0x2A25
+#define GR_GL_C4F_N3F_V3F                        0x2A26
+#define GR_GL_T2F_V3F                            0x2A27
+#define GR_GL_T4F_V4F                            0x2A28
+#define GR_GL_T2F_C4UB_V3F                       0x2A29
+#define GR_GL_T2F_C3F_V3F                        0x2A2A
+#define GR_GL_T2F_N3F_V3F                        0x2A2B
+#define GR_GL_T2F_C4F_N3F_V3F                    0x2A2C
+#define GR_GL_T4F_C4F_N3F_V4F                    0x2A2D
+
+/* Vertex Buffer Object */
+#define GR_GL_WRITE_ONLY                         0x88B9
+#define GR_GL_BUFFER_MAPPED                      0x88BC
+/* Read Format */
+#define GR_GL_IMPLEMENTATION_COLOR_READ_TYPE   0x8B9A
+#define GR_GL_IMPLEMENTATION_COLOR_READ_FORMAT 0x8B9B
+
+/* Shader Source */
+#define GR_GL_COMPILE_STATUS                 0x8B81
+#define GR_GL_INFO_LOG_LENGTH                0x8B84
+#define GR_GL_SHADER_SOURCE_LENGTH           0x8B88
+#define GR_GL_SHADER_COMPILER                0x8DFA
+
+/* Shader Binary */
+#define GR_GL_SHADER_BINARY_FORMATS          0x8DF8
+#define GR_GL_NUM_SHADER_BINARY_FORMATS      0x8DF9
+
+/* Shader Precision-Specified Types */
+#define GR_GL_LOW_FLOAT                      0x8DF0
+#define GR_GL_MEDIUM_FLOAT                   0x8DF1
+#define GR_GL_HIGH_FLOAT                     0x8DF2
+#define GR_GL_LOW_INT                        0x8DF3
+#define GR_GL_MEDIUM_INT                     0x8DF4
+#define GR_GL_HIGH_INT                       0x8DF5
+
+/* Queries */
+#define GR_GL_QUERY_COUNTER_BITS             0x8864
+#define GR_GL_CURRENT_QUERY                  0x8865
+#define GR_GL_QUERY_RESULT                   0x8866
+#define GR_GL_QUERY_RESULT_AVAILABLE         0x8867
+#define GR_GL_SAMPLES_PASSED                 0x8914
+#define GR_GL_ANY_SAMPLES_PASSED             0x8C2F
+#define GR_GL_TIME_ELAPSED                   0x88BF
+#define GR_GL_TIMESTAMP                      0x8E28
+#define GR_GL_PRIMITIVES_GENERATED           0x8C87
+#define GR_GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN 0x8C88
+
+
+/* Framebuffer Object. */
+#define GR_GL_FRAMEBUFFER                    0x8D40
+#define GR_GL_READ_FRAMEBUFFER               0x8CA8
+#define GR_GL_DRAW_FRAMEBUFFER               0x8CA9
+
+#define GR_GL_RENDERBUFFER                   0x8D41
+
+#define GR_GL_RGBA4                          0x8056
+#define GR_GL_RGB5_A1                        0x8057
+#define GR_GL_RGB565                         0x8D62
+#define GR_GL_RGBA8                          0x8058
+#define GR_GL_RGB8                           0x8051
+#define GR_GL_BGRA8                          0x93A1
+#define GR_GL_SRGB                           0x8C40
+#define GR_GL_SRGB8                          0x8C41
+#define GR_GL_SRGB_ALPHA                     0x8C42
+#define GR_GL_SRGB8_ALPHA8                   0x8C43
+#define GR_GL_DEPTH_COMPONENT16              0x81A5
+#define GR_GL_STENCIL_INDEX                  0x1901
+#define GR_GL_STENCIL_INDEX4                 0x8D47
+#define GR_GL_STENCIL_INDEX8                 0x8D48
+#define GR_GL_STENCIL_INDEX16                0x8D49
+#define GR_GL_DEPTH_STENCIL                  0x84F9
+#define GR_GL_DEPTH24_STENCIL8               0x88F0
+
+#define GR_GL_MAX_SAMPLES                    0x8D57
+
+#define GR_GL_RENDERBUFFER_WIDTH             0x8D42
+#define GR_GL_RENDERBUFFER_HEIGHT            0x8D43
+#define GR_GL_RENDERBUFFER_INTERNAL_FORMAT   0x8D44
+#define GR_GL_RENDERBUFFER_RED_SIZE          0x8D50
+#define GR_GL_RENDERBUFFER_GREEN_SIZE        0x8D51
+#define GR_GL_RENDERBUFFER_BLUE_SIZE         0x8D52
+#define GR_GL_RENDERBUFFER_ALPHA_SIZE        0x8D53
+#define GR_GL_RENDERBUFFER_DEPTH_SIZE        0x8D54
+#define GR_GL_RENDERBUFFER_STENCIL_SIZE      0x8D55
+
+#define GR_GL_FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE           0x8CD0
+#define GR_GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME           0x8CD1
+#define GR_GL_FRAMEBUFFER_ATTACHMENT_TEXTURE_LEVEL         0x8CD2
+#define GR_GL_FRAMEBUFFER_ATTACHMENT_TEXTURE_CUBE_MAP_FACE 0x8CD3
+#define GR_GL_FRAMEBUFFER_ATTACHMENT_TEXTURE_LAYER         0x8CD4
+#define GR_GL_FRAMEBUFFER_ATTACHMENT_RED_SIZE              0x8212
+#define GR_GL_FRAMEBUFFER_ATTACHMENT_GREEN_SIZE            0x8213
+#define GR_GL_FRAMEBUFFER_ATTACHMENT_BLUE_SIZE             0x8214
+#define GR_GL_FRAMEBUFFER_ATTACHMENT_ALPHA_SIZE            0x8215
+#define GR_GL_FRAMEBUFFER_ATTACHMENT_DEPTH_SIZE            0x8216
+#define GR_GL_FRAMEBUFFER_ATTACHMENT_STENCIL_SIZE          0x8217
+
+#define GR_GL_COLOR_ATTACHMENT0              0x8CE0
+#define GR_GL_DEPTH_ATTACHMENT               0x8D00
+#define GR_GL_STENCIL_ATTACHMENT             0x8D20
+#define GR_GL_DEPTH_STENCIL_ATTACHMENT       0x821A
+
+#define GR_GL_NONE                           0
+
+#define GR_GL_FRAMEBUFFER_COMPLETE                      0x8CD5
+#define GR_GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT         0x8CD6
+#define GR_GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT 0x8CD7
+#define GR_GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS         0x8CD9
+#define GR_GL_FRAMEBUFFER_UNSUPPORTED                   0x8CDD
+
+#define GR_GL_FRAMEBUFFER_BINDING            0x8CA6
+#define GR_GL_RENDERBUFFER_BINDING           0x8CA7
+#define GR_GL_MAX_RENDERBUFFER_SIZE          0x84E8
+
+#define GR_GL_INVALID_FRAMEBUFFER_OPERATION  0x0506
+
+#endif
diff --git a/include/gpu/gl/GrGLInterface.h b/include/gpu/gl/GrGLInterface.h
new file mode 100644
index 0000000000..968afab0d4
--- /dev/null
+++ b/include/gpu/gl/GrGLInterface.h
@@ -0,0 +1,429 @@
+
+/*
+ * 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 GrGLInterface_DEFINED
+#define GrGLInterface_DEFINED
+
+#include "GrGLConfig.h"
+#include "GrRefCnt.h"
+
+#if !defined(GR_GL_FUNCTION_TYPE)
+    #define GR_GL_FUNCTION_TYPE
+#endif
+
+////////////////////////////////////////////////////////////////////////////////
+
+/**
+ * Classifies GL contexts (currently as Desktop vs. ES2). This is a bitfield.
+ * A GrGLInterface (defined below) may support multiple bindings.
+ */
+enum GrGLBinding {
+    kNone_GrGLBinding = 0x0,
+
+    kDesktop_GrGLBinding = 0x01,
+    kES2_GrGLBinding = 0x02,
+
+    // for iteration of GrGLBindings
+    kFirstGrGLBinding = kDesktop_GrGLBinding,
+    kLastGrGLBinding = kES2_GrGLBinding
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+/**
+ * Helpers for glGetString()
+ */
+
+typedef uint32_t GrGLVersion;
+typedef uint32_t GrGLSLVersion;
+
+#define GR_GL_VER(major, minor) ((static_cast<int>(major) << 16) | \
+                                 static_cast<int>(minor))
+#define GR_GLSL_VER(major, minor) ((static_cast<int>(major) << 16) | \
+                                   static_cast<int>(minor))
+
+// these variants assume caller already has a string from glGetString()
+GrGLVersion GrGLGetVersionFromString(const char* versionString);
+GrGLBinding GrGLGetBindingInUseFromString(const char* versionString);
+GrGLSLVersion GrGLGetGLSLVersionFromString(const char* versionString);
+bool GrGLHasExtensionFromString(const char* ext, const char* extensionString);
+
+// these variants call glGetString()
+bool GrGLHasExtension(const GrGLInterface*, const char* ext);
+GrGLBinding GrGLGetBindingInUse(const GrGLInterface*);
+GrGLVersion GrGLGetVersion(const GrGLInterface*);
+GrGLSLVersion GrGLGetGLSLVersion(const GrGLInterface*);
+
+////////////////////////////////////////////////////////////////////////////////
+
+/**
+ * Rather than depend on platform-specific GL headers and libraries, we require
+ * the client to provide a struct of GL function pointers. This struct can be
+ * specified per-GrContext as a parameter to GrContext::Create. If NULL is
+ * passed to Create then the "default" GL interface is used. If the default is
+ * also NULL GrContext creation will fail.
+ *
+ * The default interface is returned by GrGLDefaultInterface. This function's
+ * implementation is platform-specifc. Several have been provided, along with an
+ * implementation that simply returns NULL. It is implementation-specific
+ * whether the same GrGLInterface is returned or whether a new one is created
+ * at each call. Some platforms may not be able to use a single GrGLInterface
+ * because extension function ptrs vary across contexts. Note that GrGLInterface
+ * is ref-counted. So if the same object is returned by multiple calls to 
+ * GrGLDefaultInterface, each should bump the ref count.
+ *
+ * By defining GR_GL_PER_GL_CALL_IFACE_CALLBACK to 1 the client can specify a
+ * callback function that will be called prior to each GL function call. See
+ * comments in GrGLConfig.h
+ */
+
+struct GrGLInterface;
+
+const GrGLInterface* GrGLDefaultInterface();
+
+/**
+ * Creates a GrGLInterface for a "native" GL context (e.g. WGL on windows,
+ * GLX on linux, AGL on Mac). On platforms that have context-specific function
+ * pointers for GL extensions (e.g. windows) the returned interface is only 
+ * valid for the context that was current at creation.
+ */
+const GrGLInterface* GrGLCreateNativeInterface();
+
+/**
+ * Creates a GrGLInterface for an OSMesa context.
+ */
+const GrGLInterface* GrGLCreateMesaInterface();
+
+/**
+ * Creates a null GrGLInterface that doesn't draw anything. Used for measuring
+ * CPU overhead.
+ */
+const GrGLInterface* GrGLCreateNullInterface();
+
+typedef unsigned int GrGLenum;
+typedef unsigned char GrGLboolean;
+typedef unsigned int GrGLbitfield;
+typedef signed char GrGLbyte;
+typedef char GrGLchar;
+typedef short GrGLshort;
+typedef int GrGLint;
+typedef int GrGLsizei;
+typedef int64_t GrGLint64;
+typedef unsigned char GrGLubyte;
+typedef unsigned short GrGLushort;
+typedef unsigned int GrGLuint;
+typedef uint64_t GrGLuint64;
+typedef float GrGLfloat;
+typedef float GrGLclampf;
+typedef double GrGLdouble;
+typedef double GrGLclampd;
+typedef void GrGLvoid;
+typedef long GrGLintptr;
+typedef long GrGLsizeiptr;
+
+extern "C" {
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLActiveTextureProc)(GrGLenum texture);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLAttachShaderProc)(GrGLuint program, GrGLuint shader);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLBeginQueryProc)(GrGLenum target, GrGLuint id);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLBindAttribLocationProc)(GrGLuint program, GrGLuint index, const char* name);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLBindBufferProc)(GrGLenum target, GrGLuint buffer);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLBindTextureProc)(GrGLenum target, GrGLuint texture);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLBlendColorProc)(GrGLclampf red, GrGLclampf green, GrGLclampf blue, GrGLclampf alpha);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLBindFragDataLocationProc)(GrGLuint program, GrGLuint colorNumber, const GrGLchar* name);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLBlendFuncProc)(GrGLenum sfactor, GrGLenum dfactor);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLBufferDataProc)(GrGLenum target, GrGLsizeiptr size, const GrGLvoid* data, GrGLenum usage);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLBufferSubDataProc)(GrGLenum target, GrGLintptr offset, GrGLsizeiptr size, const GrGLvoid* data);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLClearProc)(GrGLbitfield mask);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLClearColorProc)(GrGLclampf red, GrGLclampf green, GrGLclampf blue, GrGLclampf alpha);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLClearStencilProc)(GrGLint s);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLColorMaskProc)(GrGLboolean red, GrGLboolean green, GrGLboolean blue, GrGLboolean alpha);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLColorPointerProc)(GrGLint size, GrGLenum type, GrGLsizei stride, const GrGLvoid* pointer);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLCompileShaderProc)(GrGLuint shader);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLCompressedTexImage2DProc)(GrGLenum target, GrGLint level, GrGLenum internalformat, GrGLsizei width, GrGLsizei height, GrGLint border, GrGLsizei imageSize, const GrGLvoid* data);
+    typedef GrGLuint (GR_GL_FUNCTION_TYPE *GrGLCreateProgramProc)(void);
+    typedef GrGLuint (GR_GL_FUNCTION_TYPE *GrGLCreateShaderProc)(GrGLenum type);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLCullFaceProc)(GrGLenum mode);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLDeleteBuffersProc)(GrGLsizei n, const GrGLuint* buffers);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLDeleteProgramProc)(GrGLuint program);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLDeleteQueriesProc)(GrGLsizei n, const GrGLuint *ids);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLDeleteShaderProc)(GrGLuint shader);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLDeleteTexturesProc)(GrGLsizei n, const GrGLuint* textures);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLDepthMaskProc)(GrGLboolean flag);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLDisableProc)(GrGLenum cap);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLDisableVertexAttribArrayProc)(GrGLuint index);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLDrawArraysProc)(GrGLenum mode, GrGLint first, GrGLsizei count);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLDrawBufferProc)(GrGLenum mode);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLDrawBuffersProc)(GrGLsizei n, const GrGLenum* bufs);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLDrawElementsProc)(GrGLenum mode, GrGLsizei count, GrGLenum type, const GrGLvoid* indices);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLEnableProc)(GrGLenum cap);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLEnableVertexAttribArrayProc)(GrGLuint index);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLEndQueryProc)(GrGLenum target);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLFinishProc)();
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLFlushProc)();
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLFrontFaceProc)(GrGLenum mode);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLGenBuffersProc)(GrGLsizei n, GrGLuint* buffers);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLGenQueriesProc)(GrGLsizei n, GrGLuint *ids);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLGenTexturesProc)(GrGLsizei n, GrGLuint* textures);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLGetBufferParameterivProc)(GrGLenum target, GrGLenum pname, GrGLint* params);
+    typedef GrGLenum (GR_GL_FUNCTION_TYPE *GrGLGetErrorProc)();
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLGetIntegervProc)(GrGLenum pname, GrGLint* params);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLGetProgramInfoLogProc)(GrGLuint program, GrGLsizei bufsize, GrGLsizei* length, char* infolog);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLGetProgramivProc)(GrGLuint program, GrGLenum pname, GrGLint* params);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLGetQueryivProc)(GrGLenum GLtarget, GrGLenum pname, GrGLint *params);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLGetQueryObjecti64vProc)(GrGLuint id, GrGLenum pname, GrGLint64 *params);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLGetQueryObjectivProc)(GrGLuint id, GrGLenum pname, GrGLint *params);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLGetQueryObjectui64vProc)(GrGLuint id, GrGLenum pname, GrGLuint64 *params);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLGetQueryObjectuivProc)(GrGLuint id, GrGLenum pname, GrGLuint *params);    
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLGetShaderInfoLogProc)(GrGLuint shader, GrGLsizei bufsize, GrGLsizei* length, char* infolog);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLGetShaderivProc)(GrGLuint shader, GrGLenum pname, GrGLint* params);
+    typedef const GrGLubyte* (GR_GL_FUNCTION_TYPE *GrGLGetStringProc)(GrGLenum name);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLGetTexLevelParameterivProc)(GrGLenum target, GrGLint level, GrGLenum pname, GrGLint* params);
+    typedef GrGLint (GR_GL_FUNCTION_TYPE *GrGLGetUniformLocationProc)(GrGLuint program, const char* name);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLLineWidthProc)(GrGLfloat width);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLLinkProgramProc)(GrGLuint program);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLPixelStoreiProc)(GrGLenum pname, GrGLint param);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLQueryCounterProc)(GrGLuint id, GrGLenum target);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLReadBufferProc)(GrGLenum src);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLReadPixelsProc)(GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height, GrGLenum format, GrGLenum type, GrGLvoid* pixels);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLScissorProc)(GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLShaderSourceProc)(GrGLuint shader, GrGLsizei count, const char** str, const GrGLint* length);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLStencilFuncProc)(GrGLenum func, GrGLint ref, GrGLuint mask);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLStencilFuncSeparateProc)(GrGLenum face, GrGLenum func, GrGLint ref, GrGLuint mask);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLStencilMaskProc)(GrGLuint mask);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLStencilMaskSeparateProc)(GrGLenum face, GrGLuint mask);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLStencilOpProc)(GrGLenum fail, GrGLenum zfail, GrGLenum zpass);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLStencilOpSeparateProc)(GrGLenum face, GrGLenum fail, GrGLenum zfail, GrGLenum zpass);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLTexImage2DProc)(GrGLenum target, GrGLint level, GrGLint internalformat, GrGLsizei width, GrGLsizei height, GrGLint border, GrGLenum format, GrGLenum type, const GrGLvoid* pixels);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLTexParameteriProc)(GrGLenum target, GrGLenum pname, GrGLint param);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLTexStorage2DProc)(GrGLenum target, GrGLsizei levels, GrGLenum internalformat, GrGLsizei width, GrGLsizei height);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLTexSubImage2DProc)(GrGLenum target, GrGLint level, GrGLint xoffset, GrGLint yoffset, GrGLsizei width, GrGLsizei height, GrGLenum format, GrGLenum type, const GrGLvoid* pixels);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLUniform1fProc)(GrGLint location, GrGLfloat v0);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLUniform1iProc)(GrGLint location, GrGLint v0);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLUniform1fvProc)(GrGLint location, GrGLsizei count, const GrGLfloat* v);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLUniform1ivProc)(GrGLint location, GrGLsizei count, const GrGLint* v);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLUniform2fProc)(GrGLint location, GrGLfloat v0, GrGLfloat v1);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLUniform2iProc)(GrGLint location, GrGLint v0, GrGLint v1);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLUniform2fvProc)(GrGLint location, GrGLsizei count, const GrGLfloat* v);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLUniform2ivProc)(GrGLint location, GrGLsizei count, const GrGLint* v);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLUniform3fProc)(GrGLint location, GrGLfloat v0, GrGLfloat v1, GrGLfloat v2);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLUniform3iProc)(GrGLint location, GrGLint v0, GrGLint v1, GrGLint v2);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLUniform3fvProc)(GrGLint location, GrGLsizei count, const GrGLfloat* v);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLUniform3ivProc)(GrGLint location, GrGLsizei count, const GrGLint* v);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLUniform4fProc)(GrGLint location, GrGLfloat v0, GrGLfloat v1, GrGLfloat v2, GrGLfloat v3);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLUniform4iProc)(GrGLint location, GrGLint v0, GrGLint v1, GrGLint v2, GrGLint v3);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLUniform4fvProc)(GrGLint location, GrGLsizei count, const GrGLfloat* v);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLUniform4ivProc)(GrGLint location, GrGLsizei count, const GrGLint* v);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLUniformMatrix2fvProc)(GrGLint location, GrGLsizei count, GrGLboolean transpose, const GrGLfloat* value);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLUniformMatrix3fvProc)(GrGLint location, GrGLsizei count, GrGLboolean transpose, const GrGLfloat* value);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLUniformMatrix4fvProc)(GrGLint location, GrGLsizei count, GrGLboolean transpose, const GrGLfloat* value);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLUseProgramProc)(GrGLuint program);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLVertexAttrib4fvProc)(GrGLuint indx, const GrGLfloat* values);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLVertexAttribPointerProc)(GrGLuint indx, GrGLint size, GrGLenum type, GrGLboolean normalized, GrGLsizei stride, const GrGLvoid* ptr);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLViewportProc)(GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height);
+
+    // FBO Extension Functions
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLBindFramebufferProc)(GrGLenum target, GrGLuint framebuffer);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLBindRenderbufferProc)(GrGLenum target, GrGLuint renderbuffer);
+    typedef GrGLenum (GR_GL_FUNCTION_TYPE *GrGLCheckFramebufferStatusProc)(GrGLenum target);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLDeleteFramebuffersProc)(GrGLsizei n, const GrGLuint *framebuffers);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLDeleteRenderbuffersProc)(GrGLsizei n, const GrGLuint *renderbuffers);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLFramebufferRenderbufferProc)(GrGLenum target, GrGLenum attachment, GrGLenum renderbuffertarget, GrGLuint renderbuffer);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLFramebufferTexture2DProc)(GrGLenum target, GrGLenum attachment, GrGLenum textarget, GrGLuint texture, GrGLint level);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLGenFramebuffersProc)(GrGLsizei n, GrGLuint *framebuffers);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLGenRenderbuffersProc)(GrGLsizei n, GrGLuint *renderbuffers);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLGetFramebufferAttachmentParameterivProc)(GrGLenum target, GrGLenum attachment, GrGLenum pname, GrGLint* params);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLGetRenderbufferParameterivProc)(GrGLenum target, GrGLenum pname, GrGLint* params);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLRenderbufferStorageProc)(GrGLenum target, GrGLenum internalformat, GrGLsizei width, GrGLsizei height);
+
+    // Multisampling Extension Functions
+    // same prototype for ARB_FBO, EXT_FBO, GL 3.0, & Apple ES extension
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLRenderbufferStorageMultisampleProc)(GrGLenum target, GrGLsizei samples, GrGLenum internalformat, GrGLsizei width, GrGLsizei height);
+    // desktop: ext_fbo_blit, arb_fbo, gl 3.0
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLBlitFramebufferProc)(GrGLint srcX0, GrGLint srcY0, GrGLint srcX1, GrGLint srcY1, GrGLint dstX0, GrGLint dstY0, GrGLint dstX1, GrGLint dstY1, GrGLbitfield mask, GrGLenum filter);
+    // apple's es extension
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLResolveMultisampleFramebufferProc)();
+
+    // Buffer mapping (extension in ES).
+    typedef GrGLvoid* (GR_GL_FUNCTION_TYPE *GrGLMapBufferProc)(GrGLenum target, GrGLenum access);
+    typedef GrGLboolean (GR_GL_FUNCTION_TYPE *GrGLUnmapBufferProc)(GrGLenum target);
+
+    // Dual source blending
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLBindFragDataLocationIndexedProc)(GrGLuint program, GrGLuint colorNumber, GrGLuint index, const GrGLchar * name);
+}  // extern "C"
+
+#if GR_GL_PER_GL_FUNC_CALLBACK
+typedef void (*GrGLInterfaceCallbackProc)(const GrGLInterface*);
+typedef intptr_t GrGLInterfaceCallbackData;
+#endif
+
+
+enum GrGLCapability {
+    kProbe_GrGLCapability = -1
+};
+
+/*
+ * The following interface exports the OpenGL entry points used by the system.
+ * Use of OpenGL calls is disallowed.  All calls should be invoked through
+ * the global instance of this struct, defined above.
+ *
+ * IMPORTANT NOTE: The OpenGL entry points exposed here include both core GL
+ * functions, and extensions.  The system assumes that the address of the
+ * extension pointer will be valid across contexts.
+ */
+struct GR_API GrGLInterface : public GrRefCnt {
+
+    GrGLInterface();
+
+    // Validates that the GrGLInterface supports a binding. This means that
+    // the GrGLinterface advertises the binding in fBindingsExported and all
+    // the necessary function pointers have been initialized.
+    bool validate(GrGLBinding binding) const;
+
+    // Indicator variable specifying the type of GL implementation
+    // exported:  GLES{1|2} or Desktop.
+    GrGLBinding fBindingsExported;
+
+    GrGLActiveTextureProc fActiveTexture;
+    GrGLAttachShaderProc fAttachShader;
+    GrGLBeginQueryProc fBeginQuery;
+    GrGLBindAttribLocationProc fBindAttribLocation;
+    GrGLBindBufferProc fBindBuffer;
+    GrGLBindFragDataLocationProc fBindFragDataLocation;
+    GrGLBindTextureProc fBindTexture;
+    GrGLBlendColorProc fBlendColor;
+    GrGLBlendFuncProc fBlendFunc;
+    GrGLBufferDataProc fBufferData;
+    GrGLBufferSubDataProc fBufferSubData;
+    GrGLClearProc fClear;
+    GrGLClearColorProc fClearColor;
+    GrGLClearStencilProc fClearStencil;
+    GrGLColorMaskProc fColorMask;
+    GrGLColorPointerProc fColorPointer;
+    GrGLCompileShaderProc fCompileShader;
+    GrGLCompressedTexImage2DProc fCompressedTexImage2D;
+    GrGLCreateProgramProc fCreateProgram;
+    GrGLCreateShaderProc fCreateShader;
+    GrGLCullFaceProc fCullFace;
+    GrGLDeleteBuffersProc fDeleteBuffers;
+    GrGLDeleteProgramProc fDeleteProgram;
+    GrGLDeleteQueriesProc fDeleteQueries;
+    GrGLDeleteShaderProc fDeleteShader;
+    GrGLDeleteTexturesProc fDeleteTextures;
+    GrGLDepthMaskProc fDepthMask;
+    GrGLDisableProc fDisable;
+    GrGLDisableVertexAttribArrayProc fDisableVertexAttribArray;
+    GrGLDrawArraysProc fDrawArrays;
+    GrGLDrawBufferProc fDrawBuffer;
+    GrGLDrawBuffersProc fDrawBuffers;
+    GrGLDrawElementsProc fDrawElements;
+    GrGLEnableProc fEnable;
+    GrGLEnableVertexAttribArrayProc fEnableVertexAttribArray;
+    GrGLEndQueryProc fEndQuery;
+    GrGLFinishProc fFinish;
+    GrGLFlushProc fFlush;
+    GrGLFrontFaceProc fFrontFace;
+    GrGLGenBuffersProc fGenBuffers;
+    GrGLGenQueriesProc fGenQueries;
+    GrGLGenTexturesProc fGenTextures;
+    GrGLGetBufferParameterivProc fGetBufferParameteriv;
+    GrGLGetErrorProc fGetError;
+    GrGLGetIntegervProc fGetIntegerv;
+    GrGLGetQueryObjecti64vProc fGetQueryObjecti64v;
+    GrGLGetQueryObjectivProc fGetQueryObjectiv;
+    GrGLGetQueryObjectui64vProc fGetQueryObjectui64v;
+    GrGLGetQueryObjectuivProc fGetQueryObjectuiv;
+    GrGLGetQueryivProc fGetQueryiv;
+    GrGLGetProgramInfoLogProc fGetProgramInfoLog;
+    GrGLGetProgramivProc fGetProgramiv;
+    GrGLGetShaderInfoLogProc fGetShaderInfoLog;
+    GrGLGetShaderivProc fGetShaderiv;
+    GrGLGetStringProc fGetString;
+    GrGLGetTexLevelParameterivProc fGetTexLevelParameteriv;
+    GrGLGetUniformLocationProc fGetUniformLocation;
+    GrGLLineWidthProc fLineWidth;
+    GrGLLinkProgramProc fLinkProgram;
+    GrGLPixelStoreiProc fPixelStorei;
+    GrGLQueryCounterProc fQueryCounter;
+    GrGLReadBufferProc fReadBuffer;
+    GrGLReadPixelsProc fReadPixels;
+    GrGLScissorProc fScissor;
+    GrGLShaderSourceProc fShaderSource;
+    GrGLStencilFuncProc fStencilFunc;
+    GrGLStencilFuncSeparateProc fStencilFuncSeparate;
+    GrGLStencilMaskProc fStencilMask;
+    GrGLStencilMaskSeparateProc fStencilMaskSeparate;
+    GrGLStencilOpProc fStencilOp;
+    GrGLStencilOpSeparateProc fStencilOpSeparate;
+    GrGLTexImage2DProc fTexImage2D;
+    GrGLTexParameteriProc fTexParameteri;
+    GrGLTexSubImage2DProc fTexSubImage2D;
+    GrGLTexStorage2DProc fTexStorage2D;
+    GrGLUniform1fProc fUniform1f;
+    GrGLUniform1iProc fUniform1i;
+    GrGLUniform1fvProc fUniform1fv;
+    GrGLUniform1ivProc fUniform1iv;
+    GrGLUniform2fProc fUniform2f;
+    GrGLUniform2iProc fUniform2i;
+    GrGLUniform2fvProc  fUniform2fv;
+    GrGLUniform2ivProc fUniform2iv;
+    GrGLUniform3fProc fUniform3f;
+    GrGLUniform3iProc fUniform3i;
+    GrGLUniform3fvProc fUniform3fv;
+    GrGLUniform3ivProc fUniform3iv;
+    GrGLUniform4fProc fUniform4f;
+    GrGLUniform4iProc fUniform4i;
+    GrGLUniform4fvProc fUniform4fv;
+    GrGLUniform4ivProc fUniform4iv;
+    GrGLUniformMatrix2fvProc fUniformMatrix2fv;
+    GrGLUniformMatrix3fvProc fUniformMatrix3fv;
+    GrGLUniformMatrix4fvProc fUniformMatrix4fv;
+    GrGLUseProgramProc fUseProgram;
+    GrGLVertexAttrib4fvProc fVertexAttrib4fv;
+    GrGLVertexAttribPointerProc fVertexAttribPointer;
+    GrGLViewportProc fViewport;
+
+    // FBO Extension Functions
+    GrGLBindFramebufferProc fBindFramebuffer;
+    GrGLBindRenderbufferProc fBindRenderbuffer;
+    GrGLCheckFramebufferStatusProc fCheckFramebufferStatus;
+    GrGLDeleteFramebuffersProc fDeleteFramebuffers;
+    GrGLDeleteRenderbuffersProc fDeleteRenderbuffers;
+    GrGLFramebufferRenderbufferProc fFramebufferRenderbuffer;
+    GrGLFramebufferTexture2DProc fFramebufferTexture2D;
+    GrGLGenFramebuffersProc fGenFramebuffers;
+    GrGLGenRenderbuffersProc fGenRenderbuffers;
+    GrGLGetFramebufferAttachmentParameterivProc fGetFramebufferAttachmentParameteriv;
+    GrGLGetRenderbufferParameterivProc fGetRenderbufferParameteriv;
+    GrGLRenderbufferStorageProc fRenderbufferStorage;
+
+    // Multisampling Extension Functions
+    // same prototype for ARB_FBO, EXT_FBO, GL 3.0, & Apple ES extension
+    GrGLRenderbufferStorageMultisampleProc fRenderbufferStorageMultisample;
+    // desktop: ext_fbo_blit, arb_fbo, gl 3.0
+    GrGLBlitFramebufferProc fBlitFramebuffer;
+    // apple's es extension
+    GrGLResolveMultisampleFramebufferProc fResolveMultisampleFramebuffer;
+
+    // Buffer mapping (extension in ES).
+    GrGLMapBufferProc fMapBuffer;
+    GrGLUnmapBufferProc fUnmapBuffer;
+
+    // Dual Source Blending
+    GrGLBindFragDataLocationIndexedProc fBindFragDataLocationIndexed;
+
+    // Per-GL func callback
+#if GR_GL_PER_GL_FUNC_CALLBACK
+    GrGLInterfaceCallbackProc fCallback;
+    GrGLInterfaceCallbackData fCallbackData;
+#endif
+
+};
+
+#endif
diff --git a/include/gpu/gl/SkGLContext.h b/include/gpu/gl/SkGLContext.h
new file mode 100644
index 0000000000..542d1bbc06
--- /dev/null
+++ b/include/gpu/gl/SkGLContext.h
@@ -0,0 +1,63 @@
+
+/*
+ * 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 "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:
+    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;
+
+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;
+    GrGLuint fFBO;
+    const GrGLInterface* fGL;
+};
+
+/**
+ * Helper macro for using the GL context through the GrGLInterface. Example:
+ * SK_GL(glCtx, GenTextures(1, &texID));
+ */
+#define SK_GL(ctx, X) (ctx).gl()->f ## X
+
+#endif
diff --git a/include/gpu/gl/SkMesaGLContext.h b/include/gpu/gl/SkMesaGLContext.h
new file mode 100644
index 0000000000..5c329ff120
--- /dev/null
+++ b/include/gpu/gl/SkMesaGLContext.h
@@ -0,0 +1,50 @@
+
+/*
+ * 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 SkMesaGLContext_DEFINED
+#define SkMesaGLContext_DEFINED
+
+#include "SkGLContext.h"
+
+#if SK_MESA
+
+class SkMesaGLContext : public SkGLContext {
+private:
+    typedef intptr_t Context;
+
+public:
+    SkMesaGLContext();
+
+    virtual ~SkMesaGLContext();
+
+    virtual void makeCurrent() const SK_OVERRIDE;
+
+    class AutoContextRestore {
+    public:
+        AutoContextRestore();
+        ~AutoContextRestore();
+
+    private:
+        Context fOldContext;
+        GLint   fOldWidth;
+        GLint   fOldHeight;
+        GLint   fOldFormat;
+        void*   fOldImage;
+    };
+
+protected:
+    virtual const GrGLInterface* createGLContext() SK_OVERRIDE;
+    virtual void destroyGLContext() SK_OVERRIDE;
+
+private:
+    Context fContext;
+    GrGLubyte *fImage;
+};
+
+#endif
+
+#endif
diff --git a/include/gpu/gl/SkNativeGLContext.h b/include/gpu/gl/SkNativeGLContext.h
new file mode 100644
index 0000000000..36461ba7b2
--- /dev/null
+++ b/include/gpu/gl/SkNativeGLContext.h
@@ -0,0 +1,81 @@
+
+/*
+ * 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 SkNativeGLContext_DEFINED
+#define SkNativeGLContext_DEFINED
+
+#include "SkGLContext.h"
+
+#if defined(SK_BUILD_FOR_MAC)
+    #include <AGL/agl.h>
+
+#elif defined(SK_BUILD_FOR_ANDROID)
+    #include <GLES2/gl2.h>
+    #include <EGL/egl.h>
+#elif defined(SK_BUILD_FOR_UNIX)
+    #include <X11/Xlib.h>
+    #include <GL/glx.h>
+#elif defined(SK_BUILD_FOR_WIN32)
+    #include <Windows.h>
+    #include <GL/GL.h>
+#endif
+
+class SkNativeGLContext : public SkGLContext {
+public:
+    SkNativeGLContext();
+
+    virtual ~SkNativeGLContext();
+
+    virtual void makeCurrent() const SK_OVERRIDE;
+
+    class AutoContextRestore {
+    public:
+        AutoContextRestore();
+        ~AutoContextRestore();
+
+    private:
+    #if defined(SK_BUILD_FOR_MAC)
+        AGLContext fOldAGLContext;
+    #elif defined(SK_BUILD_FOR_UNIX)
+        GLXContext fOldGLXContext;
+        Display* fOldDisplay;
+        GLXDrawable fOldDrawable;
+    #elif defined(SK_BUILD_FOR_WIN32)
+        HDC fOldHDC;
+        HGLRC fOldHGLRC;
+    #elif defined(SK_BUILD_FOR_ANDROID)
+        EGLContext fOldEGLContext;
+        EGLDisplay fOldDisplay;
+        EGLSurface fOldSurface;
+    #endif
+    };
+
+protected:
+    virtual const GrGLInterface* createGLContext() SK_OVERRIDE;
+    virtual void destroyGLContext() SK_OVERRIDE;
+
+private:
+#if defined(SK_BUILD_FOR_MAC)
+    AGLContext fContext;
+#elif defined(SK_BUILD_FOR_UNIX)
+    GLXContext fContext;
+    Display* fDisplay;
+    Pixmap fPixmap;
+    GLXPixmap fGlxPixmap;
+#elif defined(SK_BUILD_FOR_WIN32)
+    HWND fWindow;
+    HDC fDeviceContext;
+    HGLRC fGlRenderContext;
+    static ATOM gWC;
+#elif defined(SK_BUILD_FOR_ANDROID)
+    EGLContext fContext;
+    EGLDisplay fDisplay;
+    EGLSurface fSurface;
+#endif
+};
+
+#endif
diff --git a/include/gpu/gl/SkNullGLContext.h b/include/gpu/gl/SkNullGLContext.h
new file mode 100644
index 0000000000..9e16cee089
--- /dev/null
+++ b/include/gpu/gl/SkNullGLContext.h
@@ -0,0 +1,27 @@
+
+/*
+ * 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 SkNullGLContext_DEFINED
+#define SkNullGLContext_DEFINED
+
+#include "SkGLContext.h"
+
+class SkNullGLContext : public SkGLContext {
+
+public:
+    SkNullGLContext() {};
+
+    virtual void makeCurrent() const SK_OVERRIDE {};
+
+protected:
+    virtual const GrGLInterface* createGLContext() SK_OVERRIDE;
+
+    virtual void destroyGLContext() SK_OVERRIDE {};
+};
+
+#endif
+