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** Public License version 3.0 as published by the Free Software Foundation
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#include <private/qopenglpaintdevice_p.h>
#include <private/qopenglcontext_p.h>
#include <private/qopenglframebufferobject_p.h>

#include <qopenglfunctions.h>

QT_BEGIN_NAMESPACE

QOpenGLPaintDevice::QOpenGLPaintDevice()
    : m_thisFBO(0)
{
}

QOpenGLPaintDevice::~QOpenGLPaintDevice()
{
}

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

void QOpenGLPaintDevice::beginPaint()
{
    QOpenGLContext *ctx = QOpenGLContext::currentContext();

    // 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_func()->current_fbo = m_thisFBO;
        QOpenGLFunctions(ctx).glBindFramebuffer(GL_FRAMEBUFFER, m_thisFBO);
    }

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

void QOpenGLPaintDevice::ensureActiveTarget()
{
    QOpenGLContext *ctx = QOpenGLContext::currentContext();

    if (ctx->d_func()->current_fbo != m_thisFBO) {
        ctx->d_func()->current_fbo = m_thisFBO;
        QOpenGLFunctions(ctx).glBindFramebuffer(GL_FRAMEBUFFER, m_thisFBO);
    }

    ctx->d_func()->default_fbo = m_thisFBO;
}

void QOpenGLPaintDevice::endPaint()
{
    // Make sure the FBO bound at beginPaint is re-bound again here:
    QOpenGLContext *ctx = QOpenGLContext::currentContext();

    if (m_previousFBO != ctx->d_func()->current_fbo) {
        ctx->d_func()->current_fbo = m_previousFBO;
        QOpenGLFunctions(ctx).glBindFramebuffer(GL_FRAMEBUFFER, m_previousFBO);
    }

    ctx->d_func()->default_fbo = 0;
}

bool QOpenGLPaintDevice::isFlipped() const
{
    return false;
}

// returns the QOpenGLPaintDevice for the given QPaintDevice
QOpenGLPaintDevice* QOpenGLPaintDevice::getDevice(QPaintDevice* pd)
{
    QOpenGLPaintDevice* glpd = 0;

    switch(pd->devType()) {
        case QInternal::FramebufferObject:
            glpd = &(static_cast<QOpenGLFramebufferObject*>(pd)->d_func()->glDevice);
            break;
        case QInternal::Pixmap: {
            qWarning("Pixmap type not supported for GL rendering");
            break;
        }
        default:
            qWarning("QOpenGLPaintDevice::getDevice() - Unknown device type %d", pd->devType());
            break;
    }

    return glpd;
}

QT_END_NAMESPACE