source: trunk/src/opengl/qglpaintdevice.cpp@ 1028

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#include <private/qglpaintdevice_p.h>
#include <private/qgl_p.h>
#include <private/qglpixelbuffer_p.h>
#include <private/qglframebufferobject_p.h>
#include <private/qwindowsurface_gl_p.h>
#ifdef Q_WS_X11
#include <private/qpixmapdata_x11gl_p.h>
#endif

#if !defined(QT_OPENGL_ES_1)
#include <private/qpixmapdata_gl_p.h>
#endif

QT_BEGIN_NAMESPACE

QGLPaintDevice::QGLPaintDevice()
    : m_thisFBO(0)
{
}

QGLPaintDevice::~QGLPaintDevice()
{
}

int QGLPaintDevice::metric(QPaintDevice::PaintDeviceMetric metric) const
{
    switch(metric) {
    case PdmWidth:
        return size().width();
    case PdmHeight:
        return size().height();
    case PdmDepth: {
        const QGLFormat f = format();
        return f.redBufferSize() + f.greenBufferSize() + f.blueBufferSize() + f.alphaBufferSize();
    }
    default:
        qWarning("QGLPaintDevice::metric() - metric %d not known", metric);
        return 0;
    }
}

void QGLPaintDevice::beginPaint()
{
    // Make sure our context is the current one:
    QGLContext *ctx = context();
    if (ctx != QGLContext::currentContext())
        ctx->makeCurrent();

    // Record the currently bound FBO so we can restore it again
    // in endPaint() and bind this device's FBO
    //
    // Note: m_thisFBO could be zero if the paint device is not
    // backed by an FBO (e.g. window back buffer).  But there could
    // be a previous FBO bound to the context which we need to
    // explicitly unbind.  Otherwise the painting will go into
    // the previous FBO instead of to the window.
    m_previousFBO = ctx->d_func()->current_fbo;

    if (m_previousFBO != m_thisFBO) {
        ctx->d_ptr->current_fbo = m_thisFBO;
        glBindFramebuffer(GL_FRAMEBUFFER_EXT, m_thisFBO);
    }

    // Set the default fbo for the context to m_thisFBO so that
    // if some raw GL code between beginNativePainting() and
    // endNativePainting() calls QGLFramebufferObject::release(),
    // painting will revert to the window surface's fbo.
    ctx->d_ptr->default_fbo = m_thisFBO;
}

void QGLPaintDevice::ensureActiveTarget()
{
    QGLContext* ctx = context();
    if (ctx != QGLContext::currentContext())
        ctx->makeCurrent();

    if (ctx->d_ptr->current_fbo != m_thisFBO) {
        ctx->d_ptr->current_fbo = m_thisFBO;
        glBindFramebuffer(GL_FRAMEBUFFER_EXT, m_thisFBO);
    }

    ctx->d_ptr->default_fbo = m_thisFBO;
}

void QGLPaintDevice::endPaint()
{
    // Make sure the FBO bound at beginPaint is re-bound again here:
    QGLContext *ctx = context();
    if (m_previousFBO != ctx->d_func()->current_fbo) {
        ctx->d_ptr->current_fbo = m_previousFBO;
        glBindFramebuffer(GL_FRAMEBUFFER_EXT, m_previousFBO);
    }

    ctx->d_ptr->default_fbo = 0;
}

QGLFormat QGLPaintDevice::format() const
{
    return context()->format();
}

bool QGLPaintDevice::alphaRequested() const
{
    return context()->d_func()->reqFormat.alpha();
}




////////////////// QGLWidgetGLPaintDevice //////////////////

QGLWidgetGLPaintDevice::QGLWidgetGLPaintDevice()
{
}

QPaintEngine* QGLWidgetGLPaintDevice::paintEngine() const
{
    return glWidget->paintEngine();
}

void QGLWidgetGLPaintDevice::setWidget(QGLWidget* w)
{
    glWidget = w;
}

void QGLWidgetGLPaintDevice::beginPaint()
{
    QGLPaintDevice::beginPaint();
    if (!glWidget->d_func()->disable_clear_on_painter_begin && glWidget->autoFillBackground()) {
        if (glWidget->testAttribute(Qt::WA_TranslucentBackground))
            glClearColor(0.0, 0.0, 0.0, 0.0);
        else {
            const QColor &c = glWidget->palette().brush(glWidget->backgroundRole()).color();
            float alpha = c.alphaF();