OpenGL get extension function

get_opengl_extension.c

//kglGetProcAddress = (wglGetProcAddress/glxGetProcAddress/eglGetProcAddress)

/*********************************************************************************/

/*  - p_GLExtensionFunctionName = The name of the function whose pointer you want to retrieve. e.g. glGenVertexArray)
    - p_ReviewBoardAbbreveration = Abbreveration of the review board that implemented the extension (e.g. ARB, KHR, INTEL, etc.)
    - p_Buffer = An external buffer we can write stuff into
*/

char* ConstructGLExtensionFunctionString(const char* p_GLExtensionFunctionName,
                                         char* p_ReviewBoardAbbreveration,
                                         char* p_Buffer)
{
    size_t extensionStringLength = strlen(p_ExtensionsPointerString);    
    size_t reviewBoardStringLength = strlen(p_ReviewBoardAbbreveration);

    memcpy(p_Buffer, p_ExtensionsPointerString, extensionStringLength);
    memcpy(p_Buffer + extensionStringLength, p_ReviewBoardAbbreveration, reviewBoardStringLength);

    return p_Buffer;
}
/*********************************************************************************/



/*********************************************************************************/

/*  - p_GLExtensionFunctionName = The name of the function whose pointer you want to retrieve. e.g. glGenVertexArray)
    - p_ReviewBoardAbbreveration = Abbreveration of the review board that implemented the extension (e.g. ARB, KHR, INTEL, etc.)
    - p_Buffer = An external buffer we can write stuff into
*/

void* GetGLExtensionFunctionPointer(const char* p_GLExtensionFunctionName,
                                         char* p_ReviewBoardAbbreveration)
{
    void* functionPointer = kglGetProcAddress(p_GLExtensionFunctionName);
    
    if (!functionPointer)
    {
        char* glFunctionNameExt = ConstructGLExtensionFunctionString(p_GLExtensionFunctionName, 
                                                                     p_ReviewBoardAbbreveration,
                                                                     (char*)alloca(128));
                
        functionPointer = kglGetProcAddress(glFunctionNameExt);
                                                                     
    }
    
    return functionPointer;
}
/*********************************************************************************/