RE_OGLExt.h

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/*
 * PROPRIETARY INFORMATION.  This software is proprietary to
 * Side Effects Software Inc., and is not to be reproduced,
 * transmitted, or disclosed in any way without written permission.
 *
 * NAME:        RE_OGLExt.h (C++)
 *
 * COMMENTS:    Cross-platform wrapper for OpenGL extensions
 *
 */

#ifndef __RE_OGLExt_h__
#define __RE_OGLExt_h__

#include "RE_API.h"
#include "RE_OGL.h"
#include "RE_Extension.h"
#include <UT/UT_Assert.h>
#include <UT/UT_UniquePtr.h>

class UT_StringSet;
class UT_String;
class re_ExtData;

class RE_API RE_OGLExt
{
public:
     RE_OGLExt();

    // NB: You must have a valid OpenGL context set before calling initialize()
    //     initialize() must be called at least once before using anything else
    void        initialize();


    bool        hasExtension( RE_Extension ext )
                {
                    UT_ASSERT( theInitializedOnce && myExtensions );
                    return (myExtensions[ext]);
                }

    // returns true if the 
    bool        hasExtensionName( const char *ext_name );

    // returns true if Houdini uses this GL extension in some way.
    bool        usesExtension( const char *glextname);

    // Returns the GL extension(s) that make up Houdini extension 'hou_ext'.
    int         getNumGLExtensionsRequired(RE_Extension ext);
    void        getGLExtensionRequired(RE_Extension hou_ext, int index,
                                       UT_String &glext);

    // Returns the core OpenGL version that this extension was rolled into.
    // If it is still not part of the core, false is returned.
    bool        getCoreVersion(RE_Extension ext,
                               int &glmajor, int &glminor) const;
                               
    //
    // These function pointer names should be copied out of glext.h and into
    // RE_OGL.h, prefixed with an 'RE_'. Use RE_ versions  in this file.
    // Note that some GL types have been typedef-ed to RE_<type>, such as
    // RE_GLchar and RE_GLintptrARB - see the top of the RE_OGL.h header.
    // All GL_* defines for the extension must be copied into RE_OGL.h.
    //

    // RE_EXT_BLEND_COLOR
    PFNGLBLENDCOLORPROC             glBlendColor;

    // RE_EXT_BLEND_MINMAX
    PFNGLBLENDEQUATIONPROC          glBlendEquation;

    // RE_EXT_BLEND_SEPARATE
    PFNGLBLENDFUNCSEPARATEPROC      glBlendFuncSeparate;
        
    // RE_EXT_TEXTURE_3D 
    PFNGLTEXIMAGE3DPROC             glTexImage3D;
    PFNGLTEXSUBIMAGE3DPROC          glTexSubImage3D;
    PFNGLCOPYTEXSUBIMAGE3DPROC      glCopyTexSubImage3D;

    // RE_EXT_MULTI_TEXTURE
    PFNGLACTIVETEXTUREPROC          glActiveTexture;
    
    // RE_EXT_SHADERS
    PFNGLATTACHSHADERPROC           glAttachShader;
    PFNGLCREATEPROGRAMPROC          glCreateProgram;
    PFNGLCREATESHADERPROC           glCreateShader;
    PFNGLDELETEPROGRAMPROC          glDeleteProgram;
    PFNGLDELETESHADERPROC           glDeleteShader;
    PFNGLDETACHSHADERPROC           glDetachShader;
    PFNGLUSEPROGRAMPROC             glUseProgram;
    PFNGLGETPROGRAMINFOLOGPROC      glGetProgramInfoLog;
    PFNGLGETSHADERINFOLOGPROC       glGetShaderInfoLog;
    PFNGLISPROGRAMPROC              glIsProgram;
    PFNGLSHADERSOURCEPROC           glShaderSource;
    PFNGLCOMPILESHADERPROC          glCompileShader;
    PFNGLLINKPROGRAMPROC            glLinkProgram;
    PFNGLVERTEXATTRIB4FVPROC        glVertexAttrib4fv;
    PFNGLVERTEXATTRIB3FVPROC        glVertexAttrib3fv;
    PFNGLVERTEXATTRIB2FVPROC        glVertexAttrib2fv;
    PFNGLVERTEXATTRIB1FVPROC        glVertexAttrib1fv;
    PFNGLVERTEXATTRIB4DVPROC        glVertexAttrib4dv;
    PFNGLVERTEXATTRIB3DVPROC        glVertexAttrib3dv;
    PFNGLVERTEXATTRIB2DVPROC        glVertexAttrib2dv;
    PFNGLVERTEXATTRIB1DVPROC        glVertexAttrib1dv;
    PFNGLVERTEXATTRIBL4DVPROC       glVertexAttribL4dv;
    PFNGLVERTEXATTRIBL3DVPROC       glVertexAttribL3dv;
    PFNGLVERTEXATTRIBL2DVPROC       glVertexAttribL2dv;
    PFNGLVERTEXATTRIBL1DVPROC       glVertexAttribL1dv;
    PFNGLVERTEXATTRIBI4IVPROC       glVertexAttribI4iv;
    PFNGLVERTEXATTRIBI3IVPROC       glVertexAttribI3iv;
    PFNGLVERTEXATTRIBI2IVPROC       glVertexAttribI2iv;
    PFNGLVERTEXATTRIBI1IVPROC       glVertexAttribI1iv;
    PFNGLVERTEXATTRIBI4UIVPROC      glVertexAttribI4uiv;
    PFNGLVERTEXATTRIBI3UIVPROC      glVertexAttribI3uiv;
    PFNGLVERTEXATTRIBI2UIVPROC      glVertexAttribI2uiv;
    PFNGLVERTEXATTRIBI1UIVPROC      glVertexAttribI1uiv;
    PFNGLGETVERTEXATTRIBDVPROC      glGetVertexAttribdv;
    PFNGLGETVERTEXATTRIBFVPROC      glGetVertexAttribfv;
    PFNGLGETVERTEXATTRIBIVPROC      glGetVertexAttribiv;
    PFNGLUNIFORM1FVPROC             glUniform1fv;
    PFNGLUNIFORM2FVPROC             glUniform2fv;
    PFNGLUNIFORM3FVPROC             glUniform3fv;
    PFNGLUNIFORM4FVPROC             glUniform4fv;
    PFNGLUNIFORM1DVPROC             glUniform1dv;
    PFNGLUNIFORM2DVPROC             glUniform2dv;
    PFNGLUNIFORM3DVPROC             glUniform3dv;
    PFNGLUNIFORM4DVPROC             glUniform4dv;
    PFNGLUNIFORM1FPROC              glUniform1f;
    PFNGLUNIFORM2FPROC              glUniform2f;
    PFNGLUNIFORM3FPROC              glUniform3f;
    PFNGLUNIFORM4FPROC              glUniform4f;
    PFNGLUNIFORM1IVPROC             glUniform1iv;
    PFNGLUNIFORM2IVPROC             glUniform2iv;
    PFNGLUNIFORM3IVPROC             glUniform3iv;
    PFNGLUNIFORM4IVPROC             glUniform4iv;
    PFNGLUNIFORM1UIVPROC            glUniform1uiv;
    PFNGLUNIFORM2UIVPROC            glUniform2uiv;
    PFNGLUNIFORM3UIVPROC            glUniform3uiv;
    PFNGLUNIFORM4UIVPROC            glUniform4uiv;
    PFNGLGETUNIFORMLOCATIONPROC     glGetUniformLocation;
    PFNGLGETUNIFORMFVPROC           glGetUniformfv;
    PFNGLGETUNIFORMIVPROC           glGetUniformiv;
    PFNGLGETUNIFORMDVPROC           glGetUniformdv;
    PFNGLUNIFORMMATRIX2FVPROC       glUniformMatrix2fv;
    PFNGLUNIFORMMATRIX3FVPROC       glUniformMatrix3fv;
    PFNGLUNIFORMMATRIX4FVPROC       glUniformMatrix4fv;
    PFNGLUNIFORMMATRIX2DVPROC       glUniformMatrix2dv;
    PFNGLUNIFORMMATRIX3DVPROC       glUniformMatrix3dv;
    PFNGLUNIFORMMATRIX4DVPROC       glUniformMatrix4dv;
    PFNGLGETACTIVEATTRIBPROC        glGetActiveAttrib;
    PFNGLGETACTIVEUNIFORMPROC       glGetActiveUniform;
    PFNGLGETATTRIBLOCATIONPROC          glGetAttribLocation;
    PFNGLBINDATTRIBLOCATIONPROC         glBindAttribLocation;
    PFNGLGETSHADERIVPROC                glGetShaderiv;
    PFNGLGETPROGRAMIVPROC               glGetProgramiv;
    PFNGLENABLEVERTEXATTRIBARRAYPROC    glEnableVertexAttribArray;
    PFNGLDISABLEVERTEXATTRIBARRAYPROC   glDisableVertexAttribArray;
    PFNGLVERTEXATTRIBPOINTERPROC        glVertexAttribPointer;
    PFNGLVERTEXATTRIBIPOINTERPROC       glVertexAttribIPointer;
    PFNGLVERTEXATTRIBLPOINTERPROC       glVertexAttribLPointer;
    PFNGLGETSHADERSOURCEPROC            glGetShaderSource;
    PFNGLVALIDATEPROGRAMPROC            glValidateProgram;
    
    // 3.0 core shaders
    PFNGLBINDFRAGDATALOCATIONPROC       glBindFragDataLocation;
    PFNGLGETFRAGDATALOCATIONPROC        glGetFragDataLocation;
        
    // RE_EXT_GEOMETRY_SHADER
    PFNGLPROGRAMPARAMETERIPROC          glProgramParameteri;

    // RE_EXT_TESS_SHADER
    PFNGLPATCHPARAMETERIPROC            glPatchParameteri;
    PFNGLPATCHPARAMETERFVPROC           glPatchParameterfv;

    // RE_EXT_SEPARATE_SHADERS
    PFNGLUSEPROGRAMSTAGESPROC           glUseProgramStages;
    PFNGLACTIVESHADERPROGRAMPROC        glActiveShaderProgram;
    PFNGLCREATESHADERPROGRAMVPROC       glCreateShaderProgramv; 
    PFNGLBINDPROGRAMPIPELINEPROC        glBindProgramPipeline;
    PFNGLDELETEPROGRAMPIPELINESPROC     glDeleteProgramPipelines;
    PFNGLGENPROGRAMPIPELINESPROC        glGenProgramPipelines;
    PFNGLISPROGRAMPIPELINEPROC          glIsProgramPipeline;
    PFNGLGETPROGRAMPIPELINEIVPROC       glGetProgramPipelineiv;
    PFNGLPROGRAMUNIFORM1IPROC           glProgramUniform1i;
    PFNGLPROGRAMUNIFORM1IVPROC          glProgramUniform1iv;
    PFNGLPROGRAMUNIFORM1FPROC           glProgramUniform1f;
    PFNGLPROGRAMUNIFORM1FVPROC          glProgramUniform1fv;
    PFNGLPROGRAMUNIFORM1DPROC           glProgramUniform1d;
    PFNGLPROGRAMUNIFORM1DVPROC          glProgramUniform1dv;
    PFNGLPROGRAMUNIFORM1UIPROC          glProgramUniform1ui;
    PFNGLPROGRAMUNIFORM1UIVPROC         glProgramUniform1uiv;
    PFNGLPROGRAMUNIFORM2IPROC           glProgramUniform2i;
    PFNGLPROGRAMUNIFORM2IVPROC          glProgramUniform2iv;
    PFNGLPROGRAMUNIFORM2FPROC           glProgramUniform2f;
    PFNGLPROGRAMUNIFORM2FVPROC          glProgramUniform2fv;
    PFNGLPROGRAMUNIFORM2DPROC           glProgramUniform2d;
    PFNGLPROGRAMUNIFORM2DVPROC          glProgramUniform2dv;
    PFNGLPROGRAMUNIFORM2UIPROC          glProgramUniform2ui;
    PFNGLPROGRAMUNIFORM2UIVPROC         glProgramUniform2uiv;
    PFNGLPROGRAMUNIFORM3IPROC           glProgramUniform3i;
    PFNGLPROGRAMUNIFORM3IVPROC          glProgramUniform3iv;
    PFNGLPROGRAMUNIFORM3FPROC           glProgramUniform3f;
    PFNGLPROGRAMUNIFORM3FVPROC          glProgramUniform3fv;
    PFNGLPROGRAMUNIFORM3DPROC           glProgramUniform3d;
    PFNGLPROGRAMUNIFORM3DVPROC          glProgramUniform3dv;
    PFNGLPROGRAMUNIFORM3UIPROC          glProgramUniform3ui;
    PFNGLPROGRAMUNIFORM3UIVPROC         glProgramUniform3uiv;
    PFNGLPROGRAMUNIFORM4IPROC           glProgramUniform4i;
    PFNGLPROGRAMUNIFORM4IVPROC          glProgramUniform4iv;
    PFNGLPROGRAMUNIFORM4FPROC           glProgramUniform4f;
    PFNGLPROGRAMUNIFORM4FVPROC          glProgramUniform4fv;
    PFNGLPROGRAMUNIFORM4DPROC           glProgramUniform4d;
    PFNGLPROGRAMUNIFORM4DVPROC          glProgramUniform4dv;
    PFNGLPROGRAMUNIFORM4UIPROC          glProgramUniform4ui;
    PFNGLPROGRAMUNIFORM4UIVPROC         glProgramUniform4uiv;
    PFNGLPROGRAMUNIFORMMATRIX2FVPROC    glProgramUniformMatrix2fv;
    PFNGLPROGRAMUNIFORMMATRIX3FVPROC    glProgramUniformMatrix3fv;
    PFNGLPROGRAMUNIFORMMATRIX4FVPROC    glProgramUniformMatrix4fv;      
    PFNGLPROGRAMUNIFORMMATRIX2DVPROC    glProgramUniformMatrix2dv;
    PFNGLPROGRAMUNIFORMMATRIX3DVPROC    glProgramUniformMatrix3dv;
    PFNGLPROGRAMUNIFORMMATRIX4DVPROC    glProgramUniformMatrix4dv;      
    PFNGLPROGRAMUNIFORMMATRIX2X3FVPROC  glProgramUniformMatrix2x3fv;
    PFNGLPROGRAMUNIFORMMATRIX3X2FVPROC  glProgramUniformMatrix3x2fv;
    PFNGLPROGRAMUNIFORMMATRIX2X4FVPROC  glProgramUniformMatrix2x4fv;
    PFNGLPROGRAMUNIFORMMATRIX4X2FVPROC  glProgramUniformMatrix4x2fv;
    PFNGLPROGRAMUNIFORMMATRIX3X4FVPROC  glProgramUniformMatrix3x4fv;
    PFNGLPROGRAMUNIFORMMATRIX4X3FVPROC  glProgramUniformMatrix4x3fv;
    PFNGLPROGRAMUNIFORMMATRIX2X3DVPROC  glProgramUniformMatrix2x3dv;
    PFNGLPROGRAMUNIFORMMATRIX3X2DVPROC  glProgramUniformMatrix3x2dv;
    PFNGLPROGRAMUNIFORMMATRIX2X4DVPROC  glProgramUniformMatrix2x4dv;
    PFNGLPROGRAMUNIFORMMATRIX4X2DVPROC  glProgramUniformMatrix4x2dv;
    PFNGLPROGRAMUNIFORMMATRIX3X4DVPROC  glProgramUniformMatrix3x4dv;
    PFNGLPROGRAMUNIFORMMATRIX4X3DVPROC  glProgramUniformMatrix4x3dv;
    PFNGLVALIDATEPROGRAMPIPELINEPROC    glValidateProgramPipeline;
    PFNGLGETPROGRAMPIPELINEINFOLOGPROC  glGetProgramPipelineInfoLog;

    // RE_EXT_PROGRAM_INTERFACE_QUERY
    PFNGLGETPROGRAMINTERFACEIVPROC      glGetProgramInterfaceiv;
    PFNGLGETPROGRAMRESOURCEINDEXPROC    glGetProgramResourceIndex;
    PFNGLGETPROGRAMRESOURCENAMEPROC     glGetProgramResourceName;
    PFNGLGETPROGRAMRESOURCEIVPROC       glGetProgramResourceiv;
    PFNGLGETPROGRAMRESOURCELOCATIONPROC glGetProgramResourceLocation;
    PFNGLGETPROGRAMRESOURCELOCATIONINDEXPROC glGetProgramResourceLocationIndex;
    // RE_EXT_TRANSFORM_FEEDBACK
    PFNGLBEGINTRANSFORMFEEDBACKPROC      glBeginTransformFeedback;
    PFNGLENDTRANSFORMFEEDBACKPROC        glEndTransformFeedback;
    PFNGLTRANSFORMFEEDBACKVARYINGSPROC   glTransformFeedbackVaryings;
    PFNGLGETTRANSFORMFEEDBACKVARYINGPROC glGetTransformFeedbackVarying;
        
    // RE_EXT_TRANSFORM_FEEDBACK_STREAM
    PFNGLBEGINQUERYINDEXEDPROC      glBeginQueryIndexed; 
    PFNGLENDQUERYINDEXEDPROC        glEndQueryIndexed;
    PFNGLGETQUERYINDEXEDIVPROC      glGetQueryIndexediv;        
    PFNGLDRAWTRANSFORMFEEDBACKSTREAMPROC glDrawTransformFeedbackStream;
        
    // RE_FRAME_BUFFER_OBJECT
    PFNGLGENFRAMEBUFFERSPROC            glGenFramebuffers;
    PFNGLDELETEFRAMEBUFFERSPROC         glDeleteFramebuffers;
    PFNGLISFRAMEBUFFERPROC              glIsFramebuffer;
    PFNGLCHECKFRAMEBUFFERSTATUSPROC     glCheckFramebufferStatus;
    PFNGLFRAMEBUFFERTEXTURE2DPROC       glFramebufferTexture2D;
    PFNGLFRAMEBUFFERTEXTURE3DPROC       glFramebufferTexture3D;
    PFNGLFRAMEBUFFERTEXTURELAYERPROC    glFramebufferTextureLayer;
    PFNGLFRAMEBUFFERTEXTUREPROC         glFramebufferTexture;
    PFNGLBINDFRAMEBUFFERPROC            glBindFramebuffer;
    
    PFNGLGENRENDERBUFFERSPROC       glGenRenderbuffers;
    PFNGLDELETERENDERBUFFERSPROC    glDeleteRenderbuffers;
    PFNGLISRENDERBUFFERPROC         glIsRenderbuffer;
    PFNGLBINDRENDERBUFFERPROC       glBindRenderbuffer;
    PFNGLRENDERBUFFERSTORAGEPROC    glRenderbufferStorage; 
    PFNGLRENDERBUFFERSTORAGEMULTISAMPLEPROC
                                    glRenderbufferStorageMultisample; 
    PFNGLBLITFRAMEBUFFERPROC        glBlitFramebuffer;
    PFNGLFRAMEBUFFERRENDERBUFFERPROC  glFramebufferRenderbuffer;
    PFNGLGETFRAMEBUFFERATTACHMENTPARAMETERIVPROC
                                    glGetFramebufferAttachmentParameteriv;
    PFNGLGENERATEMIPMAPPROC         glGenerateMipmap;

    PFNGLDRAWBUFFERSPROC            glDrawBuffers;

    // core GL 3.0
    PFNGLCLEARBUFFERIVPROC          glClearBufferiv;
    PFNGLCLEARBUFFERUIVPROC         glClearBufferuiv;
    PFNGLCLEARBUFFERFVPROC          glClearBufferfv;
    PFNGLCLEARBUFFERFIPROC          glClearBufferfi;
    
    // RE_EXT_BUFFER_STORAGE
    PFNGLBUFFERSTORAGEPROC          glBufferStorage;
    PFNGLMEMORYBARRIERPROC          glMemoryBarrier;

    // RE_ARB_GL_ARB_texture_barrier
    PFNGLTEXTUREBARRIERPROC         glTextureBarrier;

    // RE_EXT_MULTI_BIND
    PFNGLBINDBUFFERSBASEPROC        glBindBuffersBase;
    PFNGLBINDBUFFERSRANGEPROC       glBindBuffersRange;
    PFNGLBINDTEXTURESPROC           glBindTextures;
    PFNGLBINDVERTEXBUFFERSPROC      glBindVertexBuffers;
    // TODO: once the parent extensions are added, add these methods.
    //PFNGLBINDSAMPLERSPROC                 glBindSamplers;
    //PFNGLBINDIMAGETEXTURESPROC            glBindImageTextures;

    // RE_EXT_VERTEX_BUFFER_OBJECT
    // RE_EXT_PIXEL_BUFFER_OBJECT
    PFNGLGENBUFFERSPROC             glGenBuffers;
    PFNGLBINDBUFFERPROC             glBindBuffer;
    PFNGLBUFFERDATAPROC             glBufferData;
    PFNGLDELETEBUFFERSPROC          glDeleteBuffers;
    PFNGLBUFFERSUBDATAPROC          glBufferSubData;
    PFNGLGETBUFFERSUBDATAPROC       glGetBufferSubData;
    PFNGLMAPBUFFERPROC              glMapBuffer;
    PFNGLUNMAPBUFFERPROC            glUnmapBuffer;
    PFNGLMAPBUFFERRANGEPROC         glMapBufferRange;
    PFNGLFLUSHMAPPEDBUFFERRANGEPROC glFlushMappedBufferRange;
    PFNGLISBUFFERPROC               glIsBuffer;
    
    // RE_EXT_VERTEX_ARRAY_OBJECT
    PFNGLBINDVERTEXARRAYPROC                glBindVertexArray;
    PFNGLDELETEVERTEXARRAYSPROC             glDeleteVertexArrays;
    PFNGLGENVERTEXARRAYSPROC                glGenVertexArrays;
    PFNGLISVERTEXARRAYPROC                  glIsVertexArray;

    // RE_EXT_DRAW_INSTANCED
    PFNGLDRAWARRAYSINSTANCEDPROC            glDrawArraysInstanced;
    PFNGLDRAWELEMENTSINSTANCEDPROC          glDrawElementsInstanced;
    // RE_EXT_DRAW_INDIRECT
    PFNGLDRAWARRAYSINDIRECTPROC             glDrawArraysIndirect;

    // RE_EXT_INSTANCED_ARRAYS
    PFNGLVERTEXATTRIBDIVISORPROC            glVertexAttribDivisor;
    
    // RE_EXT_OCCLUSION_QUERY
    PFNGLGENQUERIESPROC                     glGenQueries;
    PFNGLDELETEQUERIESPROC                  glDeleteQueries;
    PFNGLISQUERYPROC                        glIsQuery;
    PFNGLBEGINQUERYPROC                     glBeginQuery;
    PFNGLENDQUERYPROC                       glEndQuery;
    PFNGLGETQUERYIVPROC                     glGetQueryiv;
    PFNGLGETQUERYOBJECTIVPROC               glGetQueryObjectiv;
    PFNGLGETQUERYOBJECTUIVPROC              glGetQueryObjectuiv;

    // RE_EXT_TIMER_QUERY
    PFNGLGETQUERYOBJECTI64VPROC             glGetQueryObjecti64v;
    PFNGLGETQUERYOBJECTUI64VPROC            glGetQueryObjectui64v;
    PFNGLQUERYCOUNTERPROC                   glQueryCounter;
    
    // RE_EXT_TEXTURE_MULTISAMPLE
    PFNGLTEXIMAGE2DMULTISAMPLEPROC          glTexImage2DMultisample;
    PFNGLTEXIMAGE3DMULTISAMPLEPROC          glTexImage3DMultisample;
    PFNGLGETMULTISAMPLEFVPROC               glGetMultisamplefv;
    PFNGLSAMPLEMASKIPROC                    glSampleMaski;

    // RE_EXT_UNIFORM_BUFFER
    PFNGLGETUNIFORMINDICESPROC              glGetUniformIndices;
    PFNGLGETACTIVEUNIFORMSIVPROC            glGetActiveUniformsiv;
    PFNGLGETACTIVEUNIFORMNAMEPROC           glGetActiveUniformName;
    PFNGLGETUNIFORMBLOCKINDEXPROC           glGetUniformBlockIndex;
    PFNGLGETACTIVEUNIFORMBLOCKIVPROC        glGetActiveUniformBlockiv;
    PFNGLGETACTIVEUNIFORMBLOCKNAMEPROC      glGetActiveUniformBlockName;
    PFNGLUNIFORMBLOCKBINDINGPROC            glUniformBlockBinding;
    PFNGLBINDBUFFERBASEPROC                 glBindBufferBase;
    PFNGLBINDBUFFERRANGEPROC                glBindBufferRange;
    PFNGLGETINTEGERI_VPROC                  glGetIntegeri_v;

    // RE_EXT_TEXTURE_BUFFER
    PFNGLTEXBUFFERPROC                      glTexBuffer;
    PFNGLTEXBUFFERRANGEPROC                 glTexBufferRange;

    // RE_EXT_IMAGE_LOAD_STORE
    PFNGLBINDIMAGETEXTUREPROC               glBindImageTexture;

    // RE_EXT_COMPUTE_SHADER
    PFNGLDISPATCHCOMPUTEPROC                glDispatchCompute;
    PFNGLDISPATCHCOMPUTEINDIRECTPROC        glDispatchComputeIndirect;
    
    // RE_EXT_SHADER_STORAGE_BUFFER
    PFNGLSHADERSTORAGEBLOCKBINDINGPROC      glShaderStorageBlockBinding;
    PFNGLCLEARBUFFERDATAPROC                glClearBufferData;
    PFNGLCLEARBUFFERSUBDATAPROC             glClearBufferSubData;
        
    // RE_EXT_TEXTURE_BINDLESS
    PFNGLGETTEXTUREHANDLEARBPROC            glGetTextureHandleARB;
    PFNGLGETTEXTURESAMPLERHANDLEARBPROC     glGetTextureSamplerHandleARB;
    PFNGLMAKETEXTUREHANDLERESIDENTARBPROC   glMakeTextureHandleResidentARB;     
    PFNGLMAKETEXTUREHANDLENONRESIDENTARBPROC glMakeTextureHandleNonResidentARB; 
    PFNGLGETIMAGEHANDLEARBPROC              glGetImageHandleARB;
    PFNGLMAKEIMAGEHANDLERESIDENTARBPROC     glMakeImageHandleResidentARB;
    PFNGLMAKEIMAGEHANDLENONRESIDENTARBPROC  glMakeImageHandleNonResidentARB;
    PFNGLUNIFORMHANDLEUI64ARBPROC           glUniformHandleui64ARB;
    PFNGLUNIFORMHANDLEUI64VARBPROC          glUniformHandleui64vARB;
    PFNGLPROGRAMUNIFORMHANDLEUI64ARBPROC    glProgramUniformHandleui64ARB;
    PFNGLPROGRAMUNIFORMHANDLEUI64VARBPROC   glProgramUniformHandleui64vARB;     
    PFNGLISTEXTUREHANDLERESIDENTARBPROC     glIsTextureHandleResidentARB;
    PFNGLISIMAGEHANDLERESIDENTARBPROC       glIsImageHandleResidentARB;
    PFNGLVERTEXATTRIBL1UI64ARBPROC          glVertexAttribL1ui64ARB;
    PFNGLVERTEXATTRIBL1UI64VARBPROC         glVertexAttribL1ui64vARB;
    PFNGLGETVERTEXATTRIBLUI64VARBPROC       glGetVertexAttribLui64vARB;

    // RE_EXT_TEXTURE_COPY
    PFNGLCOPYIMAGESUBDATAPROC               glCopyImageSubData;
    
    // RE_EXT_PRIMITIVE_RESTART
    PFNGLPRIMITIVERESTARTINDEXPROC          glPrimitiveRestartIndex;

    // RE_EXT_ELEMENTS_BASE_VERTEX
    PFNGLDRAWELEMENTSBASEVERTEXPROC         glDrawElementsBaseVertex;
    PFNGLDRAWRANGEELEMENTSBASEVERTEXPROC    glDrawRangeElementsBaseVertex;
    PFNGLDRAWELEMENTSINSTANCEDBASEVERTEXPROC
                                            glDrawElementsInstancedBaseVertex;
    PFNGLMULTIDRAWELEMENTSBASEVERTEXPROC    glMultiDrawElementsBaseVertex;

    // RE_EXT_ELEMENTS_BASE_INSTANCE
    PFNGLDRAWARRAYSINSTANCEDBASEINSTANCEPROC
                                            glDrawArraysInstancedBaseInstance;
    PFNGLDRAWELEMENTSINSTANCEDBASEINSTANCEPROC
                                            glDrawElementsInstancedBaseInstance;
    PFNGLDRAWELEMENTSINSTANCEDBASEVERTEXBASEINSTANCEPROC
                                  glDrawElementsInstancedBaseVertexBaseInstance;
    
    // RE_EXT_SYNC
    PFNGLFENCESYNCPROC              glFenceSync;
    PFNGLISSYNCPROC                 glIsSync;
    PFNGLDELETESYNCPROC             glDeleteSync;
    PFNGLWAITSYNCPROC               glWaitSync;
    PFNGLGETINTEGER64VPROC          glGetInteger64v;
    PFNGLGETSYNCIVPROC              glGetSynciv;
    PFNGLCLIENTWAITSYNCPROC         glClientWaitSync;

    // RE_EXT_CONDITIONAL_RENDER
    PFNGLBEGINCONDITIONALRENDERPROC glBeginConditionalRender;
    PFNGLENDCONDITIONALRENDERPROC   glEndConditionalRender;

    // GL 1.2
    PFNGLDRAWRANGEELEMENTSPROC      glDrawRangeElements;

    // RE_EXT_SAMPLE_SHADING
    PFNGLMINSAMPLESHADINGPROC       glMinSampleShading;

    // RE_EXT_DEPTH_BUFFER_NO_CLAMP
    RE_PFNGLDEPTHRANGEDNVPROC       glDepthRangedNV;
    RE_PFNGLDEPTHBOUNDSDNVPROC      glDepthBoundsdNV;
    RE_PFNGLCLEARDEPTHDNVPROC       glClearDepthdNV;

    // RE_EXT_DEBUG_OUTPUT
    PFNGLDEBUGMESSAGECONTROLPROC    glDebugMessageControl; 
    PFNGLDEBUGMESSAGEINSERTPROC     glDebugMessageInsert;
    PFNGLDEBUGMESSAGECALLBACKPROC   glDebugMessageCallback;
    PFNGLGETDEBUGMESSAGELOGPROC     glGetDebugMessageLog;

    // RE_EXT_DIRECT_STATE_ACCESS (add as needed)
    RE_PFNGLBINDMULTITEXTUREEXTPROC glBindMultiTextureEXT;

    // RE_EXT_DEBUG_KRONOS
    PFNGLPUSHDEBUGGROUPPROC         glPushDebugGroup;
    PFNGLPOPDEBUGGROUPPROC          glPopDebugGroup;
    PFNGLOBJECTLABELPROC            glObjectLabel;
    PFNGLGETOBJECTLABELPROC         glGetObjectLabel;
    PFNGLOBJECTPTRLABELPROC         glObjectPtrLabel;
    PFNGLGETOBJECTPTRLABELPROC      glGetObjectPtrLabel;

    PFNGLGETGRAPHICSRESETSTATUSPROC glGetGraphicsResetStatus;
        
    // RE_EXT_EXTERNAL_OBJECTS
    RE_PFNGLGETUNSIGNEDBYTEVEXTPROC   glGetUnsignedBytevEXT;
    RE_PFNGLGETUNSIGNEDBYTEI_VEXTPROC glGetUnsignedBytei_vEXT;
    RE_PFNGLCREATEMEMORYOBJECTSEXTPROC     glCreateMemoryObjectsEXT;
    RE_PFNGLDELETEMEMORYOBJECTSEXTPROC     glDeleteMemoryObjectsEXT;
    RE_PFNGLISMEMORYOBJECTEXTPROC          glIsMemoryObjectEXT;
    RE_PFNGLMEMORYOBJECTPARAMETERIVEXTPROC glMemoryObjectParameterivEXT;
    RE_PFNGLGETMEMORYOBJECTPARAMETERIVEXTPROC glGetMemoryObjectParameterivEXT;
    RE_PFNGLTEXSTORAGEMEM1DEXTPROC            glTexStorageMem1DEXT;
    RE_PFNGLTEXSTORAGEMEM2DEXTPROC            glTexStorageMem2DEXT;
    RE_PFNGLTEXSTORAGEMEM2DMULTISAMPLEEXTPROC glTexStorageMem2DMultisampleEXT;
    RE_PFNGLTEXSTORAGEMEM3DEXTPROC            glTexStorageMem3DEXT;
    RE_PFNGLTEXSTORAGEMEM3DMULTISAMPLEEXTPROC glTexStorageMem3DMultisampleEXT;
    RE_PFNGLBUFFERSTORAGEMEMEXTPROC           glBufferStorageMemEXT;
    RE_PFNGLTEXTURESTORAGEMEM1DEXTPROC            glTextureStorageMem1DEXT;
    RE_PFNGLTEXTURESTORAGEMEM2DEXTPROC            glTextureStorageMem2DEXT;
    RE_PFNGLTEXTURESTORAGEMEM2DMULTISAMPLEEXTPROC glTextureStorageMem2DMultisampleEXT;
    RE_PFNGLTEXTURESTORAGEMEM3DEXTPROC            glTextureStorageMem3DEXT;
    RE_PFNGLTEXTURESTORAGEMEM3DMULTISAMPLEEXTPROC glTextureStorageMem3DMultisampleEXT;
    RE_PFNGLNAMEDBUFFERSTORAGEMEMEXTPROC          glNamedBufferStorageMemEXT;
    RE_PFNGLGENSEMAPHORESEXTPROC               glGenSemaphoresEXT;
    RE_PFNGLDELETESEMAPHORESEXTPROC            glDeleteSemaphoresEXT;
    RE_PFNGLISSEMAPHOREEXTPROC                 glIsSemaphoreEXT;
    RE_PFNGLSEMAPHOREPARAMETERUI64VEXTPROC     glSemaphoreParameterui64vEXT;
    RE_PFNGLGETSEMAPHOREPARAMETERUI64VEXTPROC  glGetSemaphoreParameterui64vEXT;
    RE_PFNGLWAITSEMAPHOREEXTPROC               glWaitSemaphoreEXT;
    RE_PFNGLSIGNALSEMAPHOREEXTPROC             glSignalSemaphoreEXT;
#ifdef WIN32
    RE_PFNGLIMPORTMEMORYWIN32HANDLEEXTPROC     glImportMemoryWin32HandleEXT;
    RE_PFNGLIMPORTMEMORYWIN32NAMEEXTPROC       glImportMemoryWin32NameEXT;
    RE_PFNGLIMPORTSEMAPHOREWIN32HANDLEEXTPROC  glImportSemaphoreWin32HandleEXT;
    RE_PFNGLIMPORTSEMAPHOREWIN32NAMEEXTPROC    glImportSemaphoreWin32NameEXT;
#else
    RE_PFNGLIMPORTMEMORYFDEXTPROC      glImportMemoryFdEXT;
    RE_PFNGLIMPORTSEMAPHOREFDEXTPROC   glImportSemaphoreFdEXT;
#endif

    // RE_EXT_INTERNALFORMAT_QUERY
    PFNGLGETINTERNALFORMATIVPROC        glGetInternalformativ;
    PFNGLGETINTERNALFORMATI64VPROC      glGetInternalformati64v;

#ifdef WIN32
    RE_PFNWGLSWAPINTERVALPROC       wglSwapIntervalEXT;
    RE_PFNWGLGETEXTENSIONSSTRINGPROC wglGetExtensionsStringEXT;
#elif !defined(MBSD_COCOA)
    RE_PFNGLXSWAPINTERVALSGIPROC    glXSwapIntervalSGI;
#endif

    PFNGLGETSTRINGIPROC             glGetStringi;

    // Only RE_Render should ever call these, and only to work around driver
    // issues.
    void                 enableExtension( RE_Extension ext );
    void                 disableExtension( RE_Extension ext );

    static void         *getExtFunction(void *a_out_handle, const char *symbol);

private:
    void                 setupTheExtensions();
    void                 checkExtensions(re_ExtData *exts,
                                         const UT_StringSet &syms);

    bool                        *myExtensions;
    UT_UniquePtr<UT_StringSet>   myGLExtensionTable;

    static bool                  theInitializedOnce;
};

#endif // __RE_OGLExt_h__