{

int gl_active; /* to stop switching drivers while we have a valid context */

#if SDL_VIDEO_OPENGL

PIXELFORMATDESCRIPTOR GL_pfd;

HDC GL_hdc;

HGLRC GL_hrc;

int pixel_format;

int WGL_ARB_pixel_format;

void *(WINAPI * wglGetProcAddress) (const char *proc);

HGLRC(WINAPI * wglCreateContext) (HDC hdc);

BOOL(WINAPI * wglDeleteContext) (HGLRC hglrc);

BOOL(WINAPI * wglMakeCurrent) (HDC hdc, HGLRC hglrc);

BOOL(WINAPI * wglChoosePixelFormatARB) (HDC hdc,

const int *piAttribIList,

const FLOAT * pfAttribFList,

UINT nMaxFormats,

int *piFormats,

UINT * nNumFormats);

BOOL(WINAPI * wglGetPixelFormatAttribivARB) (HDC hdc, int iPixelFormat,

int iLayerPlane,

UINT nAttributes,

const int *piAttributes,

int *piValues);

void (WINAPI * wglSwapIntervalEXT) (int interval);

int (WINAPI * wglGetSwapIntervalEXT) (void);

#endif /* SDL_VIDEO_OPENGL */