git.mutantstargoat.com Git - vrlugburz/blob - src/opengl.c

   1 #include <stdio.h>
   2 #include <string.h>
   3 #include "opengl.h"
   4 #include <GL/glx.h>
   5
   6 #define LOADPROC(type, func) \
   7         do { \
   8                 if(!(func = (type)glXGetProcAddress((unsigned char*)#func))) { \
   9                         fputs("failed to load entry point: " #func, stderr); \
  10                         return -1; \
  11                 } \
  12         } while(0)
  13
  14 int init_opengl(void)
  15 {
  16         const char *glext, *glver;
  17
  18         if(!(glver = (const char*)glGetString(GL_VERSION))) {
  19                 fprintf(stderr, "failed to retrieve OpenGL version string\n");
  20                 return -1;
  21         }
  22         glcaps.ver_major = 1;
  23         glcaps.ver_minor = 0;
  24         sscanf(glver, "%d.%d", &glcaps.ver_major, &glcaps.ver_minor);
  25
  26         if(!(glext = (const char*)glGetString(GL_EXTENSIONS))) {
  27                 fprintf(stderr, "failed to retrieve OpenGL extensions string\n");
  28                 return -1;
  29         }
  30
  31         if(glcaps.ver_major >= 2 || glcaps.ver_minor >= 5 || (strstr(glext, "GL_ARB_vertex_buffer_object"))) {
  32                 glcaps.vbo = 1;
  33         }
  34
  35         if(glcaps.ver_major >= 2 || (strstr(glext, "GL_ARB_vertex_shader") && strstr(glext, "GL_ARB_fragment_shader"))) {
  36                 glcaps.sdr = 1;
  37         }
  38
  39         if(glcaps.vbo) {
  40                 LOADPROC(PFNGLGENBUFFERSPROC, glGenBuffers);
  41                 LOADPROC(PFNGLDELETEBUFFERSPROC, glDeleteBuffers);
  42                 LOADPROC(PFNGLBINDBUFFERPROC, glBindBuffer);
  43                 LOADPROC(PFNGLBUFFERDATAPROC, glBufferData);
  44         }
  45
  46         if(glcaps.sdr) {
  47                 LOADPROC(PFNGLCREATEPROGRAMPROC, glCreateProgram);
  48                 LOADPROC(PFNGLDELETEPROGRAMPROC, glDeleteProgram);
  49                 LOADPROC(PFNGLATTACHSHADERPROC, glAttachShader);
  50                 LOADPROC(PFNGLLINKPROGRAMPROC, glLinkProgram);
  51                 LOADPROC(PFNGLGETPROGRAMIVPROC, glGetProgramiv);
  52                 LOADPROC(PFNGLGETPROGRAMINFOLOGPROC, glGetProgramInfoLog);
  53                 LOADPROC(PFNGLUSEPROGRAMPROC, glUseProgram);
  54                 LOADPROC(PFNGLGETUNIFORMLOCATIONPROC, glGetUniformLocation);
  55                 LOADPROC(PFNGLUNIFORM1IPROC, glUniform1i);
  56                 LOADPROC(PFNGLUNIFORM1FPROC, glUniform1f);
  57                 LOADPROC(PFNGLUNIFORM2FPROC, glUniform2f);
  58                 LOADPROC(PFNGLUNIFORM3FPROC, glUniform3f);
  59                 LOADPROC(PFNGLUNIFORM4FPROC, glUniform4f);
  60                 LOADPROC(PFNGLUNIFORMMATRIX4FVPROC, glUniformMatrix4fv);
  61                 LOADPROC(PFNGLGETATTRIBLOCATIONPROC, glGetAttribLocation);
  62                 LOADPROC(PFNGLVERTEXATTRIB3FPROC, glVertexAttrib3f);
  63                 LOADPROC(PFNGLCREATESHADERPROC, glCreateShader);
  64                 LOADPROC(PFNGLDELETESHADERPROC, glDeleteShader);
  65                 LOADPROC(PFNGLSHADERSOURCEPROC, glShaderSource);
  66                 LOADPROC(PFNGLCOMPILESHADERPROC, glCompileShader);
  67                 LOADPROC(PFNGLGETSHADERIVPROC, glGetShaderiv);
  68                 LOADPROC(PFNGLGETSHADERINFOLOGPROC, glGetShaderInfoLog);
  69                 LOADPROC(PFNGLBINDATTRIBLOCATIONPROC, glBindAttribLocation);
  70                 LOADPROC(PFNGLENABLEVERTEXATTRIBARRAYPROC, glEnableVertexAttribArray);
  71                 LOADPROC(PFNGLDISABLEVERTEXATTRIBARRAYPROC, glDisableVertexAttribArray);
  72                 LOADPROC(PFNGLVERTEXATTRIBPOINTERPROC, glVertexAttribPointer);
  73         }
  74
  75         return 0;
  76 }