GDraw extension wrangling

gistfile1.c

///////////////////////////////////////////////////////////////////////////////
//
//  Extensions (we map to GL 2.0 function names for a uniform interface
//  across platforms)
//

#define GDRAW_GL_EXTENSION_LIST \
   /*  identifier                      import                              procname */ \
   /* GL_ARB_multitexture */ \
   GLE(ActiveTexture,                  "ActiveTextureARB",                 ACTIVETEXTUREARB) \
   /* GL_ARB_texture_compression */ \
   GLE(CompressedTexImage2D,           "CompressedTexImage2DARB",          COMPRESSEDTEXIMAGE2DARB) \
   /* GL_ARB_vertex_buffer_object */ \
   GLE(GenBuffers,                     "GenBuffersARB",                    GENBUFFERSARB) \
   GLE(DeleteBuffers,                  "DeleteBuffersARB",                 DELETEBUFFERSARB) \
   GLE(BindBuffer,                     "BindBufferARB",                    BINDBUFFERARB) \
   GLE(BufferData,                     "BufferDataARB",                    BUFFERDATAARB) \
   GLE(MapBuffer,                      "MapBufferARB",                     MAPBUFFERARB) \
   GLE(UnmapBuffer,                    "UnmapBufferARB",                   UNMAPBUFFERARB) \
   GLE(VertexAttribPointer,            "VertexAttribPointerARB",           VERTEXATTRIBPOINTERARB) \
   GLE(EnableVertexAttribArray,        "EnableVertexAttribArrayARB",       ENABLEVERTEXATTRIBARRAYARB) \
   GLE(DisableVertexAttribArray,       "DisableVertexAttribArrayARB",      DISABLEVERTEXATTRIBARRAYARB) \
   /* GL_ARB_shader_objects */ \
   GLE(CreateShader,                   "CreateShaderObjectARB",            CREATESHADEROBJECTARB) \
   GLE(DeleteShader,                   "DeleteObjectARB",                  DELETEOBJECTARB) \
   GLE(ShaderSource,                   "ShaderSourceARB",                  SHADERSOURCEARB) \
   GLE(CompileShader,                  "CompileShaderARB",                 COMPILESHADERARB) \
   GLE(GetShaderiv,                    "GetObjectParameterivARB",          GETOBJECTPARAMETERIVARB) \
   GLE(GetShaderInfoLog,               "GetInfoLogARB",                    GETINFOLOGARB) \
   GLE(CreateProgram,                  "CreateProgramObjectARB",           CREATEPROGRAMOBJECTARB) \
   GLE(DeleteProgram,                  "DeleteObjectARB",                  DELETEOBJECTARB) \
   GLE(AttachShader,                   "AttachObjectARB",                  ATTACHOBJECTARB) \
   GLE(LinkProgram,                    "LinkProgramARB",                   LINKPROGRAMARB) \
   GLE(GetUniformLocation,             "GetUniformLocationARB",            GETUNIFORMLOCATIONARB) \
   GLE(UseProgram,                     "UseProgramObjectARB",              USEPROGRAMOBJECTARB) \
   GLE(GetProgramiv,                   "GetObjectParameterivARB",          GETOBJECTPARAMETERIVARB) \
   GLE(GetProgramInfoLog,              "GetInfoLogARB",                    GETINFOLOGARB) \
   GLE(Uniform1i,                      "Uniform1iARB",                     UNIFORM1IARB) \
   GLE(Uniform4f,                      "Uniform4fARB",                     UNIFORM4FARB) \
   GLE(Uniform4fv,                     "Uniform4fvARB",                    UNIFORM4FVARB) \
   /* GL_ARB_vertex_shader */ \
   GLE(BindAttribLocation,             "BindAttribLocationARB",            BINDATTRIBLOCATIONARB) \
   /* GL_EXT_framebuffer_object */ \
   GLE(GenRenderbuffers,               "GenRenderbuffersEXT",              GENRENDERBUFFERSEXT) \
   GLE(DeleteRenderbuffers,            "DeleteRenderbuffersEXT",           DELETERENDERBUFFERSEXT) \
   GLE(BindRenderbuffer,               "BindRenderbufferEXT",              BINDRENDERBUFFEREXT) \
   GLE(RenderbufferStorage,            "RenderbufferStorageEXT",           RENDERBUFFERSTORAGEEXT) \
   GLE(GenFramebuffers,                "GenFramebuffersEXT",               GENFRAMEBUFFERSEXT) \
   GLE(DeleteFramebuffers,             "DeleteFramebuffersEXT",            DELETEFRAMEBUFFERSEXT) \
   GLE(BindFramebuffer,                "BindFramebufferEXT",               BINDFRAMEBUFFEREXT) \
   GLE(CheckFramebufferStatus,         "CheckFramebufferStatusEXT",        CHECKFRAMEBUFFERSTATUSEXT) \
   GLE(FramebufferRenderbuffer,        "FramebufferRenderbufferEXT",       FRAMEBUFFERRENDERBUFFEREXT) \
   GLE(FramebufferTexture2D,           "FramebufferTexture2DEXT",          FRAMEBUFFERTEXTURE2DEXT) \
   GLE(GenerateMipmap,                 "GenerateMipmapEXT",                GENERATEMIPMAPEXT) \
   /* GL_EXT_framebuffer_blit */ \
   GLE(BlitFramebuffer,                "BlitFramebufferEXT",               BLITFRAMEBUFFEREXT) \
   /* GL_EXT_framebuffer_multisample */ \
   GLE(RenderbufferStorageMultisample, "RenderbufferStorageMultisampleEXT",RENDERBUFFERSTORAGEMULTISAMPLEEXT) \
   /* <end> */

typedef GLhandleARB GLhandle;

// Extensions
#define GLE(id, import, procname) static PFNGL##procname##PROC gl##id;
GDRAW_GL_EXTENSION_LIST
#undef GLE

static void load_extensions(void)
{
#define GLE(id, import, procname) gl##id = (PFNGL##procname##PROC) wglGetProcAddress("gl" import);
   GDRAW_GL_EXTENSION_LIST
#undef GLE
}