glew/auto/src/glew_init_gl.c
2007-03-19 13:33:36 +00:00

111 lines
3.1 KiB
C

/* ------------------------------------------------------------------------- */
/*
* Search for name in the extensions string. Use of strstr()
* is not sufficient because extension names can be prefixes of
* other extension names. Could use strtok() but the constant
* string returned by glGetString might be in read-only memory.
*/
GLboolean glewGetExtension (const char* name)
{
GLubyte* p;
GLubyte* end;
GLuint len = _glewStrLen((const GLubyte*)name);
p = (GLubyte*)glGetString(GL_EXTENSIONS);
if (0 == p) return GL_FALSE;
end = p + _glewStrLen(p);
while (p < end)
{
GLuint n = _glewStrCLen(p, ' ');
if (len == n && _glewStrSame((const GLubyte*)name, p, n)) return GL_TRUE;
p += n+1;
}
return GL_FALSE;
}
/* ------------------------------------------------------------------------- */
#ifndef GLEW_MX
static
#endif
GLenum glewContextInit (GLEW_CONTEXT_ARG_DEF_LIST)
{
const GLubyte* s;
GLuint dot, major, minor;
/* query opengl version */
s = glGetString(GL_VERSION);
dot = _glewStrCLen(s, '.');
major = dot-1;
minor = dot+1;
if (dot == 0 || s[minor] == '\0')
return GLEW_ERROR_NO_GL_VERSION;
if (s[major] == '1' && s[minor] == '0')
{
return GLEW_ERROR_GL_VERSION_10_ONLY;
}
else
{
CONST_CAST(GLEW_VERSION_1_1) = GL_TRUE;
if (s[major] >= '2')
{
CONST_CAST(GLEW_VERSION_1_2) = GL_TRUE;
CONST_CAST(GLEW_VERSION_1_3) = GL_TRUE;
CONST_CAST(GLEW_VERSION_1_4) = GL_TRUE;
CONST_CAST(GLEW_VERSION_1_5) = GL_TRUE;
CONST_CAST(GLEW_VERSION_2_0) = GL_TRUE;
if (s[minor] >= '1')
{
CONST_CAST(GLEW_VERSION_2_1) = GL_TRUE;
}
}
else
{
if (s[minor] >= '5')
{
CONST_CAST(GLEW_VERSION_1_2) = GL_TRUE;
CONST_CAST(GLEW_VERSION_1_3) = GL_TRUE;
CONST_CAST(GLEW_VERSION_1_4) = GL_TRUE;
CONST_CAST(GLEW_VERSION_1_5) = GL_TRUE;
CONST_CAST(GLEW_VERSION_2_0) = GL_FALSE;
CONST_CAST(GLEW_VERSION_2_1) = GL_FALSE;
}
if (s[minor] == '4')
{
CONST_CAST(GLEW_VERSION_1_2) = GL_TRUE;
CONST_CAST(GLEW_VERSION_1_3) = GL_TRUE;
CONST_CAST(GLEW_VERSION_1_4) = GL_TRUE;
CONST_CAST(GLEW_VERSION_1_5) = GL_FALSE;
CONST_CAST(GLEW_VERSION_2_0) = GL_FALSE;
CONST_CAST(GLEW_VERSION_2_1) = GL_FALSE;
}
if (s[minor] == '3')
{
CONST_CAST(GLEW_VERSION_1_2) = GL_TRUE;
CONST_CAST(GLEW_VERSION_1_3) = GL_TRUE;
CONST_CAST(GLEW_VERSION_1_4) = GL_FALSE;
CONST_CAST(GLEW_VERSION_1_5) = GL_FALSE;
CONST_CAST(GLEW_VERSION_2_0) = GL_FALSE;
CONST_CAST(GLEW_VERSION_2_1) = GL_FALSE;
}
if (s[minor] == '2')
{
CONST_CAST(GLEW_VERSION_1_2) = GL_TRUE;
CONST_CAST(GLEW_VERSION_1_3) = GL_FALSE;
CONST_CAST(GLEW_VERSION_1_4) = GL_FALSE;
CONST_CAST(GLEW_VERSION_1_5) = GL_FALSE;
CONST_CAST(GLEW_VERSION_2_0) = GL_FALSE;
CONST_CAST(GLEW_VERSION_2_1) = GL_FALSE;
}
if (s[minor] < '2')
{
CONST_CAST(GLEW_VERSION_1_2) = GL_FALSE;
CONST_CAST(GLEW_VERSION_1_3) = GL_FALSE;
CONST_CAST(GLEW_VERSION_1_4) = GL_FALSE;
CONST_CAST(GLEW_VERSION_1_5) = GL_FALSE;
CONST_CAST(GLEW_VERSION_2_0) = GL_FALSE;
CONST_CAST(GLEW_VERSION_2_1) = GL_FALSE;
}
}
}
/* initialize extensions */