Category Archives: development

I’ve been playing around with OpenGL (again) on both Apple and Microsoft platform and I soon found out that things are not simple in Windows (as usual).

The glGenBuffers and related functions are nowhere to be found on the default installation of the OpenGL SDK. It’s not THAT painful to get it done (if you know where to look).

First, you’ll need glext.h that you download from the OpenGL website, then you’ll need to declare and reference the functions at runtime. Something like this:

#include "glext.h"
PFNGLDELETEBUFFERSPROC glDeleteBuffers;
PFNGLGENBUFFERSPROC glGenBuffers;
PFNGLBINDBUFFERPROC glBindBuffer;
PFNGLBUFFERDATAPROC glBufferData;
PFNGLBUFFERSUBDATAPROC glBufferSubData;
PFNGLMAPBUFFERPROC glMapBuffer;
PFNGLUNMAPBUFFERPROC glUnmapBuffer;
void initGLFunctions() {
  glGenBuffers = (PFNGLGENBUFFERSPROC) wglGetProcAddress(LPCSTR("glGenBuffers"));
  glDeleteBuffers = (PFNGLDELETEBUFFERSPROC) wglGetProcAddress(LPCSTR("glDeleteBuffers"));
  glBindBuffer = (PFNGLBINDBUFFERPROC) wglGetProcAddress(LPCSTR("glBindBuffer"));
  glBufferData = (PFNGLBUFFERDATAPROC) wglGetProcAddress(LPCSTR("glBufferData"));
  glBufferSubData = (PFNGLBUFFERSUBDATAPROC) wglGetProcAddress(LPCSTR("glBufferSubData"));
  glMapBuffer = (PFNGLMAPBUFFERPROC) wglGetProcAddress(LPCSTR("glMapBuffer"));
  glUnmapBuffer = (PFNGLUNMAPBUFFERPROC) wglGetProcAddress(LPCSTR("glUnmapBuffer"));
  if (glGenBuffers == NULL) {
    const char *version;
    fprintf(stderr, "Cannot properly initialize extension functions!\n");
    version = (const char*)glGetString(GL_VERSION);
    fprintf(stderr, "OpenGL version:%s\n", version);
  }
}

The above code provides you everything you need to use the VBO related functions, but there are many many functions declared inside glext.h. You could create prototypes like above for any of them.

Beware the version of your graphics card driver. Microsoft default driver usually comes with support to OpenGL 1.1 version only, wich is not good enough for VBO.