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//========================================================================
// GLFW - An OpenGL framework
// File: glext.c
// Platform: Any
// API version: 2.6
// WWW: http://glfw.sourceforge.net
//------------------------------------------------------------------------
// Copyright (c) 2002-2006 Camilla Berglund
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
// claim that you wrote the original software. If you use this software
// in a product, an acknowledgment in the product documentation would
// be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such, and must not
// be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source
// distribution.
//
//========================================================================
#include "internal.h"
//************************************************************************
//**** GLFW internal functions ****
//************************************************************************
//========================================================================
// _glfwStringInExtensionString() - Check if a string can be found in an
// OpenGL extension string
//========================================================================
int _glfwStringInExtensionString( const char *string,
const GLubyte *extensions )
{
const GLubyte *start;
GLubyte *where, *terminator;
// It takes a bit of care to be fool-proof about parsing the
// OpenGL extensions string. Don't be fooled by sub-strings,
// etc.
start = extensions;
while( 1 )
{
where = (GLubyte *) strstr( (const char *) start, string );
if( !where )
{
return GL_FALSE;
}
terminator = where + strlen( string );
if( where == start || *(where - 1) == ' ' )
{
if( *terminator == ' ' || *terminator == '\0' )
{
break;
}
}
start = terminator;
}
return GL_TRUE;
}
//************************************************************************
//**** GLFW user functions ****
//************************************************************************
//========================================================================
// glfwExtensionSupported() - Check if an OpenGL extension is available
// at runtime
//========================================================================
GLFWAPI int GLFWAPIENTRY glfwExtensionSupported( const char *extension )
{
const GLubyte *extensions;
GLubyte *where;
// Is GLFW initialized?
if( !_glfwInitialized || !_glfwWin.Opened )
{
return GL_FALSE;
}
// Extension names should not have spaces
where = (GLubyte *) strchr( extension, ' ' );
if( where || *extension == '\0' )
{
return GL_FALSE;
}
// Check if extension is in the standard OpenGL extensions string
extensions = (GLubyte *) glGetString( GL_EXTENSIONS );
if( extensions != NULL )
{
if( _glfwStringInExtensionString( extension, extensions ) )
{
return GL_TRUE;
}
}
// Additional platform specific extension checking (e.g. WGL)
if( _glfwPlatformExtensionSupported( extension ) )
{
return GL_TRUE;
}
return GL_FALSE;
}
//========================================================================
// glfwGetProcAddress() - Get the function pointer to an OpenGL function.
// This function can be used to get access to extended OpenGL functions.
//========================================================================
GLFWAPI void * GLFWAPIENTRY glfwGetProcAddress( const char *procname )
{
// Is GLFW initialized?
if( !_glfwInitialized || !_glfwWin.Opened )
{
return NULL;
}
return _glfwPlatformGetProcAddress( procname );
}
//========================================================================
// glfwGetGLVersion() - Get OpenGL version
//========================================================================
GLFWAPI void GLFWAPIENTRY glfwGetGLVersion( int *major, int *minor,
int *rev )
{
GLuint _major, _minor = 0, _rev = 0;
const GLubyte *version;
GLubyte *ptr;
// Is GLFW initialized?
if( !_glfwInitialized || !_glfwWin.Opened )
{
return;
}
// Get OpenGL version string
version = glGetString( GL_VERSION );
if( !version )
{
return;
}
// Parse string
ptr = (GLubyte*) version;
for( _major = 0; *ptr >= '0' && *ptr <= '9'; ptr ++ )
{
_major = 10*_major + (*ptr - '0');
}
if( *ptr == '.' )
{
ptr ++;
for( _minor = 0; *ptr >= '0' && *ptr <= '9'; ptr ++ )
{
_minor = 10*_minor + (*ptr - '0');
}
if( *ptr == '.' )
{
ptr ++;
for( _rev = 0; *ptr >= '0' && *ptr <= '9'; ptr ++ )
{
_rev = 10*_rev + (*ptr - '0');
}
}
}
// Return parsed values
if( major != NULL )
{
*major = _major;
}
if( minor != NULL )
{
*minor = _minor;
}
if( rev != NULL )
{
*rev = _rev;
}
}
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