Files
simgear/simgear/screen/extensions.cxx
T

66 lines
2.2 KiB
C++

/*
*
* Copyright (c) 2001 César Blecua Udías All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* CESAR BLECUA UDIAS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
* OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
*/
#include "extensions.hxx"
#include <cstring>
#include <osg/GL> // for glGetString
bool SGSearchExtensionsString(const char *extString, const char *extName) {
// Returns GL_TRUE if the *extName string appears in the *extString string,
// surrounded by white spaces, or GL_FALSE otherwise.
const char *p, *end;
int n, extNameLen;
if ((extString == NULL) || (extName == NULL))
return false;
extNameLen = strlen(extName);
p=extString;
end = p + strlen(p);
while (p < end) {
n = strcspn(p, " ");
if ((extNameLen == n) && (strncmp(extName, p, n) == 0))
return GL_TRUE;
p += (n + 1);
}
return GL_FALSE;
}
bool SGIsOpenGLExtensionSupported(const char *extName) {
// Returns GL_TRUE if the OpenGL Extension whose name is *extName
// is supported by the system, or GL_FALSE otherwise.
//
// The *extName string must follow the OpenGL extensions naming scheme
// (ie: "GL_type_extension", like GL_EXT_convolution)
return SGSearchExtensionsString((const char *)glGetString(GL_EXTENSIONS),extName);
}