vcs.maemo.org Git - neverball/blob - share/glext.c

   1 /*
   2  * Copyright (C) 2003-2011 Neverball authors
   3  *
   4  * NEVERBALL is  free software; you can redistribute  it and/or modify
   5  * it under the  terms of the GNU General  Public License as published
   6  * by the Free  Software Foundation; either version 2  of the License,
   7  * or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT  ANY  WARRANTY;  without   even  the  implied  warranty  of
  11  * MERCHANTABILITY or  FITNESS FOR A PARTICULAR PURPOSE.   See the GNU
  12  * General Public License for more details.
  13  */
  14
  15 #include <SDL.h>
  16
  17 #include "glext.h"
  18
  19 /*---------------------------------------------------------------------------*/
  20
  21 #ifndef CONF_OPENGLES
  22
  23 PFNGLACTIVETEXTURE_PROC    glActiveTexture_;
  24
  25 PFNGLGENBUFFERS_PROC       glGenBuffers_;
  26 PFNGLBINDBUFFER_PROC       glBindBuffer_;
  27 PFNGLBUFFERDATA_PROC       glBufferData_;
  28 PFNGLBUFFERSUBDATA_PROC    glBufferSubData_;
  29 PFNGLDELETEBUFFERS_PROC    glDeleteBuffers_;
  30 PFNGLISBUFFER_PROC         glIsBuffer_;
  31
  32 PFNGLPOINTPARAMETERFV_PROC glPointParameterfv_;
  33
  34 #endif
  35
  36 /*---------------------------------------------------------------------------*/
  37
  38 int glext_check(const char *needle)
  39 {
  40     const GLubyte *haystack, *c;
  41
  42     /* Search for the given string in the OpenGL extension strings. */
  43
  44     for (haystack = glGetString(GL_EXTENSIONS); *haystack; haystack++)
  45     {
  46         for (c = (const GLubyte *) needle; *c && *haystack; c++, haystack++)
  47             if (*c != *haystack)
  48                 break;
  49
  50         if ((*c == 0) && (*haystack == ' ' || *haystack == '\0'))
  51             return 1;
  52     }
  53
  54     return 0;
  55 }
  56
  57 /*---------------------------------------------------------------------------*/
  58
  59 #define SDL_GL_GFPA(fun, str) do {     \
  60     ptr = SDL_GL_GetProcAddress(str);  \
  61     memcpy(&fun, &ptr, sizeof (void *)); \
  62 } while(0)
  63
  64 /*---------------------------------------------------------------------------*/
  65
  66 void glext_init(void)
  67 {
  68 #ifndef CONF_OPENGLES
  69
  70     void *ptr;
  71
  72     if (glext_check("ARB_multitexture"))
  73         SDL_GL_GFPA(glActiveTexture_, "glActiveTextureARB");
  74
  75     if (glext_check("ARB_vertex_buffer_object"))
  76     {
  77         SDL_GL_GFPA(glGenBuffers_,    "glGenBuffersARB");
  78         SDL_GL_GFPA(glBindBuffer_,    "glBindBufferARB");
  79         SDL_GL_GFPA(glBufferData_,    "glBufferDataARB");
  80         SDL_GL_GFPA(glBufferSubData_, "glBufferSubDataARB");
  81         SDL_GL_GFPA(glDeleteBuffers_, "glDeleteBuffersARB");
  82         SDL_GL_GFPA(glIsBuffer_,      "glIsBufferARB");
  83     }
  84
  85     if (glext_check("ARB_point_parameters"))
  86         SDL_GL_GFPA(glPointParameterfv_, "glPointParameterfvARB");
  87
  88 #endif
  89 }
  90
  91 /*---------------------------------------------------------------------------*/