/*
 * Copyright © 2014 Jon Turney
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

/*
  Wrapper functions for calling WGL extension functions
 */

#include "wgl.h"

#include <stdio.h>

#define RESOLVE_DECL(type) \
    static type type##proc = NULL;

#define PRERESOLVE(type, symbol) \
    type##proc = (type)wglGetProcAddress(symbol); \
    if (type##proc == NULL) \
       printf("Can't resolve \"%s\"\n", symbol);

#define CHECK_RESOLVED(type, retval) \
  if (type##proc == NULL) { \
    return retval; \
  }

#define RESOLVED_PROC(type) type##proc

RESOLVE_DECL(PFNWGLGETEXTENSIONSSTRINGARBPROC);
RESOLVE_DECL(PFNWGLCREATECONTEXTATTRIBSARBPROC);
RESOLVE_DECL(PFNWGLMAKECONTEXTCURRENTARBPROC);
RESOLVE_DECL(PFNWGLCREATEPBUFFERARBPROC);
RESOLVE_DECL(PFNWGLGETPBUFFERDCARBPROC);
RESOLVE_DECL(PFNWGLRELEASEPBUFFERDCARBPROC);
RESOLVE_DECL(PFNWGLDESTROYPBUFFERARBPROC);

void wglResolveExtensionProcs(void)
{
  PRERESOLVE(PFNWGLGETEXTENSIONSSTRINGARBPROC, "wglGetExtensionsStringARB");
  PRERESOLVE(PFNWGLCREATECONTEXTATTRIBSARBPROC, "wglCreateContextAttribsARB");
  PRERESOLVE(PFNWGLMAKECONTEXTCURRENTARBPROC, "wglMakeContextCurrentARB");
  PRERESOLVE(PFNWGLCREATEPBUFFERARBPROC, "wglCreatePbufferARB");
  PRERESOLVE(PFNWGLGETPBUFFERDCARBPROC, "wglGetPbufferDCARB");
  PRERESOLVE(PFNWGLRELEASEPBUFFERDCARBPROC, "wglReleasePbufferDCARB");
  PRERESOLVE(PFNWGLDESTROYPBUFFERARBPROC, "wglDestroyPbufferARB");
}

const char *wglGetExtensionsStringARB(HDC hdc_)
{
   CHECK_RESOLVED(PFNWGLGETEXTENSIONSSTRINGARBPROC, "");
   return RESOLVED_PROC(PFNWGLGETEXTENSIONSSTRINGARBPROC)(hdc_);
}

HGLRC wglCreateContextAttribsARB(HDC hdc_, HGLRC hShareContext_,
                                     const int *attribList_)
{
   CHECK_RESOLVED(PFNWGLCREATECONTEXTATTRIBSARBPROC, NULL);
   return RESOLVED_PROC(PFNWGLCREATECONTEXTATTRIBSARBPROC)(hdc_, hShareContext_, attribList_);
}

BOOL wglMakeContextCurrentARB(HDC hDrawDC_, HDC hReadDC_, HGLRC hglrc_)
{
   CHECK_RESOLVED(PFNWGLMAKECONTEXTCURRENTARBPROC, false);
   return RESOLVED_PROC(PFNWGLMAKECONTEXTCURRENTARBPROC)(hDrawDC_, hReadDC_, hglrc_);
}

HPBUFFERARB wglCreatePbufferARB(HDC hDC_, int iPixelFormat_, int iWidth_,
                                int iHeight_, const int *piAttribList_)
{
   CHECK_RESOLVED(PFNWGLCREATEPBUFFERARBPROC, NULL);
   return RESOLVED_PROC(PFNWGLCREATEPBUFFERARBPROC)(hDC_, iPixelFormat_, iWidth_, iHeight_, piAttribList_);
}

HDC wglGetPbufferDCARB(HPBUFFERARB hPbuffer_)
{
   CHECK_RESOLVED(PFNWGLGETPBUFFERDCARBPROC, NULL);
   return RESOLVED_PROC(PFNWGLGETPBUFFERDCARBPROC)(hPbuffer_);
}

int wglReleasePbufferDCARB(HPBUFFERARB hPbuffer_, HDC hDC_)
{
   CHECK_RESOLVED(PFNWGLRELEASEPBUFFERDCARBPROC, 0)
   return RESOLVED_PROC(PFNWGLRELEASEPBUFFERDCARBPROC)(hPbuffer_, hDC_);
}

BOOL wglDestroyPbufferARB(HPBUFFERARB hPbuffer_)
{
   CHECK_RESOLVED(PFNWGLDESTROYPBUFFERARBPROC, false);
   return RESOLVED_PROC(PFNWGLDESTROYPBUFFERARBPROC)(hPbuffer_);
}