glew/auto/src/glew_init_gl.c

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/* ------------------------------------------------------------------------- */
/*
* 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;
GLint major, minor;
/* query opengl version */
s = glGetString(GL_VERSION);
dot = _glewStrCLen(s, '.');
if (dot == 0)
return GLEW_ERROR_NO_GL_VERSION;
major = s[dot-1]-'0';
minor = s[dot+1]-'0';
if (minor < 0 || minor > 9)
minor = 0;
if (major<0 || major>9)
return GLEW_ERROR_NO_GL_VERSION;
if (major == 1 && minor == 0)
{
return GLEW_ERROR_GL_VERSION_10_ONLY;
}
else
{
CONST_CAST(GLEW_VERSION_4_1) = ( major > 4 ) || ( major == 4 && minor >= 1 ) ? GL_TRUE : GL_FALSE;
CONST_CAST(GLEW_VERSION_4_0) = GLEW_VERSION_4_1 == GL_TRUE || ( major == 4 ) ? GL_TRUE : GL_FALSE;
CONST_CAST(GLEW_VERSION_3_3) = GLEW_VERSION_4_0 == GL_TRUE || ( major == 3 && minor >= 3 ) ? GL_TRUE : GL_FALSE;
CONST_CAST(GLEW_VERSION_3_2) = GLEW_VERSION_3_3 == GL_TRUE || ( major == 3 && minor >= 2 ) ? GL_TRUE : GL_FALSE;
CONST_CAST(GLEW_VERSION_3_1) = GLEW_VERSION_3_2 == GL_TRUE || ( major == 3 && minor >= 1 ) ? GL_TRUE : GL_FALSE;
CONST_CAST(GLEW_VERSION_3_0) = GLEW_VERSION_3_1 == GL_TRUE || ( major == 3 ) ? GL_TRUE : GL_FALSE;
CONST_CAST(GLEW_VERSION_2_1) = GLEW_VERSION_3_0 == GL_TRUE || ( major == 2 && minor >= 1 ) ? GL_TRUE : GL_FALSE;
CONST_CAST(GLEW_VERSION_2_0) = GLEW_VERSION_2_1 == GL_TRUE || ( major == 2 ) ? GL_TRUE : GL_FALSE;
CONST_CAST(GLEW_VERSION_1_5) = GLEW_VERSION_2_0 == GL_TRUE || ( major == 1 && minor >= 5 ) ? GL_TRUE : GL_FALSE;
CONST_CAST(GLEW_VERSION_1_4) = GLEW_VERSION_1_5 == GL_TRUE || ( major == 1 && minor >= 4 ) ? GL_TRUE : GL_FALSE;
CONST_CAST(GLEW_VERSION_1_3) = GLEW_VERSION_1_4 == GL_TRUE || ( major == 1 && minor >= 3 ) ? GL_TRUE : GL_FALSE;
CONST_CAST(GLEW_VERSION_1_2_1) = GLEW_VERSION_1_3 == GL_TRUE ? GL_TRUE : GL_FALSE;
CONST_CAST(GLEW_VERSION_1_2) = GLEW_VERSION_1_2_1 == GL_TRUE || ( major == 1 && minor >= 2 ) ? GL_TRUE : GL_FALSE;
CONST_CAST(GLEW_VERSION_1_1) = GLEW_VERSION_1_2 == GL_TRUE || ( major == 1 && minor >= 1 ) ? GL_TRUE : GL_FALSE;
}
/* initialize extensions */