source: trunk/src/opengl/qglpixelbuffer_mac.mm@ 681

/****************************************************************************
**
** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation ([email protected])
**
** This file is part of the QtOpenGL module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** 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.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** 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.
**
** If you have questions regarding the use of this file, please contact
** Nokia at [email protected].
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qglpixelbuffer.h"
#include "qglpixelbuffer_p.h"

#ifndef QT_MAC_USE_COCOA
#include <AGL/agl.h>
#endif

#include <qimage.h>
#include <private/qgl_p.h>
#include <qdebug.h>

QT_BEGIN_NAMESPACE

#ifndef GL_TEXTURE_RECTANGLE_EXT
#define GL_TEXTURE_RECTANGLE_EXT 0x84F5
#endif

static int nearest_gl_texture_size(int v)
{
    int n = 0, last = 0;
    for (int s = 0; s < 32; ++s) {
        if (((v>>s) & 1) == 1) {
            ++n;
            last = s;
        }
    }
    if (n > 1)
        return 1 << (last+1);
    return 1 << last;
}

bool QGLPixelBufferPrivate::init(const QSize &size, const QGLFormat &f, QGLWidget *shareWidget)
{
#ifdef QT_MAC_USE_COCOA
    Q_Q(QGLPixelBuffer);
    // create a dummy context
    QGLContext context(f, q);
    context.create(shareWidget ? shareWidget->context() : 0);

    if (context.isSharing())
        share_ctx = shareWidget->context()->d_func()->cx;

    // steal the NSOpenGLContext and update the format
    ctx = context.d_func()->cx;
    context.d_func()->cx = 0;
    // d->cx will be set to ctx later in
    // QGLPixelBufferPrivate::common_init, so we need to retain it:
    [static_cast<NSOpenGLContext *>(ctx) retain];

    format = context.format();

    GLenum target = GL_TEXTURE_2D;

    if ((QGLExtensions::glExtensions() & QGLExtensions::TextureRectangle)
        && (size.width() != nearest_gl_texture_size(size.width())
            || size.height() != nearest_gl_texture_size(size.height())))
    {
        target = GL_TEXTURE_RECTANGLE_EXT;
    }

    pbuf = [[NSOpenGLPixelBuffer alloc] initWithTextureTarget:target
                                        textureInternalFormat:GL_RGBA
                                        textureMaxMipMapLevel:0
                                                  pixelsWide:size.width()
                                                  pixelsHigh:size.height()];
    if (!pbuf) {
        qWarning("QGLPixelBuffer: Cannot create a pbuffer");
        return false;
    }

    [static_cast<NSOpenGLContext *>(ctx) setPixelBuffer:static_cast<NSOpenGLPixelBuffer *>(pbuf)
                                            cubeMapFace:0
                                            mipMapLevel:0
                                   currentVirtualScreen:0];
    return true;
#else
    GLint attribs[40], i=0;
    attribs[i++] = AGL_RGBA;
    attribs[i++] = AGL_BUFFER_SIZE;
    attribs[i++] = 32;
    attribs[i++] = AGL_LEVEL;
    attribs[i++] = f.plane();
    if (f.redBufferSize() != -1) {
        attribs[i++] = AGL_RED_SIZE;
        attribs[i++] = f.redBufferSize();