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#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();

    }

    if (f.greenBufferSize() != -1) {

        attribs[i++] = AGL_GREEN_SIZE;

        attribs[i++] = f.greenBufferSize();

    }

    if (f.blueBufferSize() != -1) {

        attribs[i++] = AGL_BLUE_SIZE;

        attribs[i++] = f.blueBufferSize();

    }

    if (f.stereo())

        attribs[i++] = AGL_STEREO;

    if (f.alpha()) {

        attribs[i++] = AGL_ALPHA_SIZE;

        attribs[i++] = f.alphaBufferSize() == -1 ? 8 : f.alphaBufferSize();

    }

    if (f.stencil()) {

        attribs[i++] = AGL_STENCIL_SIZE;

        attribs[i++] = f.stencilBufferSize() == -1 ? 8 : f.stencilBufferSize();

    }

    if (f.depth()) {

        attribs[i++] = AGL_DEPTH_SIZE;

        attribs[i++] = f.depthBufferSize() == -1 ? 32 : f.depthBufferSize();

    }

    if (f.accum()) {

        attribs[i++] = AGL_ACCUM_RED_SIZE;

        attribs[i++] = f.accumBufferSize() == -1 ? 16 : f.accumBufferSize();

        attribs[i++] = AGL_ACCUM_BLUE_SIZE;

        attribs[i++] = f.accumBufferSize() == -1 ? 16 : f.accumBufferSize();

        attribs[i++] = AGL_ACCUM_GREEN_SIZE;

        attribs[i++] = f.accumBufferSize() == -1 ? 16 : f.accumBufferSize();

        attribs[i++] = AGL_ACCUM_ALPHA_SIZE;

        attribs[i++] = f.accumBufferSize() == -1 ? 16 : f.accumBufferSize();

    }

    if (f.sampleBuffers()) {

        attribs[i++] = AGL_SAMPLE_BUFFERS_ARB;

        attribs[i++] = 1;

        attribs[i++] = AGL_SAMPLES_ARB;

        attribs[i++] = f.samples() == -1 ? 4 : f.samples();

    }

    attribs[i] = AGL_NONE;

    AGLPixelFormat format = aglChoosePixelFormat(0, 0, attribs);

    if (!format) {

	qWarning("QGLPixelBuffer: Unable to find a pixel format (AGL error %d).",

		 (int) aglGetError());

        return false;

    }

    GLint res;

    aglDescribePixelFormat(format, AGL_LEVEL, &res);

    this->format.setPlane(res);

    aglDescribePixelFormat(format, AGL_DOUBLEBUFFER, &res);

    this->format.setDoubleBuffer(res);

    aglDescribePixelFormat(format, AGL_DEPTH_SIZE, &res);

    this->format.setDepth(res);

    if (this->format.depth())

	this->format.setDepthBufferSize(res);

    aglDescribePixelFormat(format, AGL_RGBA, &res);

    this->format.setRgba(res);

    aglDescribePixelFormat(format, AGL_RED_SIZE, &res);

    this->format.setRedBufferSize(res);

    aglDescribePixelFormat(format, AGL_GREEN_SIZE, &res);

    this->format.setGreenBufferSize(res);

    aglDescribePixelFormat(format, AGL_BLUE_SIZE, &res);

    this->format.setBlueBufferSize(res);

    aglDescribePixelFormat(format, AGL_ALPHA_SIZE, &res);

    this->format.setAlpha(res);

    if (this->format.alpha())

	this->format.setAlphaBufferSize(res);

    aglDescribePixelFormat(format, AGL_ACCUM_RED_SIZE, &res);

    this->format.setAccum(res);

    if (this->format.accum())

	this->format.setAccumBufferSize(res);

    aglDescribePixelFormat(format, AGL_STENCIL_SIZE, &res);

    this->format.setStencil(res);

    if (this->format.stencil())

	this->format.setStencilBufferSize(res);

    aglDescribePixelFormat(format, AGL_STEREO, &res);

    this->format.setStereo(res);

    aglDescribePixelFormat(format, AGL_SAMPLE_BUFFERS_ARB, &res);

    this->format.setSampleBuffers(res);

    if (this->format.sampleBuffers()) {

        aglDescribePixelFormat(format, AGL_SAMPLES_ARB, &res);

        this->format.setSamples(res);

    }

    AGLContext share = 0;

    if (shareWidget)

	share = share_ctx = static_cast<AGLContext>(shareWidget->d_func()->glcx->d_func()->cx);

    ctx = aglCreateContext(format, share);

    if (!ctx) {

	qWarning("QGLPixelBuffer: Unable to create a context (AGL error %d).",

		 (int) aglGetError());

	return false;

    }

    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;

    }

    if (!aglCreatePBuffer(size.width(), size.height(), target, GL_RGBA, 0, &pbuf)) {

	qWarning("QGLPixelBuffer: Unable to create a pbuffer (AGL error %d).",

		 (int) aglGetError());

	return false;

    }

    if (!aglSetPBuffer(ctx, pbuf, 0, 0, 0)) {

	qWarning("QGLPixelBuffer: Unable to set pbuffer (AGL error %d).",

		 (int) aglGetError());

	return false;

    }

    aglDestroyPixelFormat(format);

    return true;

#endif

}

bool QGLPixelBufferPrivate::cleanup()

{

#ifdef QT_MAC_USE_COCOA

    [static_cast<NSOpenGLPixelBuffer *>(pbuf) release];

    pbuf = 0;

    [static_cast<NSOpenGLContext *>(ctx) release];

    ctx = 0;

#else

    aglDestroyPBuffer(pbuf);

#endif

    return true;

}

bool QGLPixelBuffer::bindToDynamicTexture(GLuint texture_id)

{

    Q_D(QGLPixelBuffer);

    if (d->invalid || !d->share_ctx)

        return false;

#ifdef QT_MAC_USE_COCOA

    NSOpenGLContext *oldContext = [NSOpenGLContext currentContext];

    if (d->share_ctx != oldContext)

        [static_cast<NSOpenGLContext *>(d->share_ctx) makeCurrentContext];

    glBindTexture(GL_TEXTURE_2D, texture_id);

    [static_cast<NSOpenGLContext *>(d->share_ctx)

            setTextureImageToPixelBuffer:static_cast<NSOpenGLPixelBuffer *>(d->pbuf)

            colorBuffer:GL_FRONT];

    if (oldContext && oldContext != d->share_ctx)

        [oldContext makeCurrentContext];

    return true;

#else

    aglSetCurrentContext(d->share_ctx);

    glBindTexture(GL_TEXTURE_2D, texture_id);

    aglTexImagePBuffer(d->share_ctx, d->pbuf, GL_FRONT);

    return true;

#endif

}

#ifdef Q_MAC_COMPAT_GL_FUNCTIONS

bool QGLPixelBuffer::bindToDynamicTexture(QMacCompatGLuint texture_id)

{

    return bindToDynamicTexture(GLuint(texture_id));

}

#endif

void QGLPixelBuffer::releaseFromDynamicTexture()

{

}

GLuint QGLPixelBuffer::generateDynamicTexture() const

{

#ifdef QT_MAC_USE_COCOA

    Q_D(const QGLPixelBuffer);

    NSOpenGLContext *oldContext = [NSOpenGLContext currentContext];

    if (d->share_ctx != oldContext)

        [static_cast<NSOpenGLContext *>(d->share_ctx) makeCurrentContext];

    GLuint texture;

    glGenTextures(1, &texture);

    glBindTexture(GL_TEXTURE_2D, texture);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

    if (oldContext && oldContext != d->share_ctx)

        [oldContext makeCurrentContext];

    return texture;

#else

    GLuint texture;

    glGenTextures(1, &texture);

    glBindTexture(GL_TEXTURE_2D, texture);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

    return texture;

#endif

}

bool QGLPixelBuffer::hasOpenGLPbuffers()

{

    return true;

}

QT_END_NAMESPACE