gl3w-style loader generator for SDL2

glgen.py

# Usage: python glgen.py SDL_opengl.h (or SDL_opengl_glext.h if you're on the 2.0.4 development branch)

import sys
import re

ext_file = file(sys.argv[1])
functions = []
for match in re.finditer(r" APIENTRY (gl.*?) \(", ext_file.read()):
    functions.append((match.group(1), "PFN%sPROC" % (match.group(1).upper(),)))

loader_file = file('SDL_opengl_load.h', 'w')

def out(str):
    loader_file.write(str)

out('#ifdef __cplusplus\nextern "C"\n{\n#endif\n\n#ifndef _SDL_opengl_load_h\n#define _SDL_opengl_load_h\n\nvoid SDL_GL_LoadExtensions(void);\n\n')

for name, typedef in functions:
    out('extern %s SDL_%s;\n#define %s SDL_%s\n\n' % (typedef, name, name, name))

out('#endif\n\n#ifdef SDL_OPENGL_LOAD_IMPLEMENT\n\n')

for name, typedef in functions:
    out('%s SDL_%s;\n' % (typedef, name))

out('\nvoid SDL_GL_LoadExtensions(void)\n{\n')
for name, typedef in functions:
    out('    SDL_%s = (%s) SDL_GL_GetProcAddress("%s");\n' % (name, typedef, name))

out('}\n\n#endif\n\n#ifdef __cplusplus\n}\n#endif\n')