/****************************************************************************
**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia.  For licensing terms and
** conditions see http://qt.digia.com/licensing.  For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
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** rights.  These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
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** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
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** $QT_END_LICENSE$
**
****************************************************************************/

#include "qopengl.h"
#include "qopengl_p.h"

#include "qopenglcontext.h"
#include "qopenglfunctions.h"

QT_BEGIN_NAMESPACE

#if defined(QT_OPENGL_3)
typedef const GLubyte * (QOPENGLF_APIENTRYP qt_glGetStringi)(GLenum, GLuint);
#endif

QOpenGLExtensionMatcher::QOpenGLExtensionMatcher()
{
    const char *extensionStr = reinterpret_cast<const char *>(glGetString(GL_EXTENSIONS));

    if (extensionStr) {
        QByteArray ba(extensionStr);
        QList<QByteArray> extensions = ba.split(' ');
        m_extensions = extensions.toSet();
#if !defined(QT_OPENGL_3)
    }
#else
    } else {
        // clear error state
        while (glGetError()) {}

        QOpenGLContext *ctx = QOpenGLContext::currentContext();
        if (ctx) {
            qt_glGetStringi glGetStringi = (qt_glGetStringi)ctx->getProcAddress("glGetStringi");

            if (!glGetStringi)
                return;

            GLint numExtensions;
            glGetIntegerv(GL_NUM_EXTENSIONS, &numExtensions);

            for (int i = 0; i < numExtensions; ++i) {
                const char *str = reinterpret_cast<const char *>(glGetStringi(GL_EXTENSIONS, i));
                m_extensions.insert(str);
            }
        }
    }
#endif
}

QT_END_NAMESPACE