/********************************************************************
 KWin - the KDE window manager
 This file is part of the KDE project.

Copyright (C) 2006 Lubos Lunak <l.lunak@kde.org>
Copyright (C) 2009 Fredrik Höglund <fredrik@kde.org>
Copyright (C) 2013 Martin Gräßlin <mgraesslin@kde.org>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
*********************************************************************/
#include "scene_xrender.h"

#include "utils.h"

#ifdef KWIN_HAVE_XRENDER_COMPOSITING

#include "toplevel.h"
#include "client.h"
#include "composite.h"
#include "deleted.h"
#include "effects.h"
#include "main.h"
#include "overlaywindow.h"
#include "workspace.h"
#include "xcbutils.h"
#include "kwinxrenderutils.h"
#if HAVE_WAYLAND
#include "wayland_backend.h"
#include <KWayland/Client/shm_pool.h>
#include <KWayland/Client/surface.h>
#endif
#include "decorations/decoratedclient.h"

#include <xcb/xfixes.h>

#include <QDebug>
#include <QtGui/QPainter>
#include <qmath.h>

namespace KWin
{

ScreenPaintData SceneXrender::screen_paint;

#define DOUBLE_TO_FIXED(d) ((xcb_render_fixed_t) ((d) * 65536))
#define FIXED_TO_DOUBLE(f) ((double) ((f) / 65536.0))


//****************************************
// XRenderBackend
//****************************************
XRenderBackend::XRenderBackend()
    : m_buffer(XCB_RENDER_PICTURE_NONE)
    , m_failed(false)
{
    if (!Xcb::Extensions::self()->isRenderAvailable()) {
        setFailed("No XRender extension available");
        return;
    }
    if (!Xcb::Extensions::self()->isFixesRegionAvailable()) {
        setFailed("No XFixes v3+ extension available");
        return;
    }
}

XRenderBackend::~XRenderBackend()
{
    if (m_buffer) {
        xcb_render_free_picture(connection(), m_buffer);
    }
}

OverlayWindow* XRenderBackend::overlayWindow()
{
    return NULL;
}

void XRenderBackend::showOverlay()
{
}

void XRenderBackend::setBuffer(xcb_render_picture_t buffer)
{
    if (m_buffer != XCB_RENDER_PICTURE_NONE) {
        xcb_render_free_picture(connection(), m_buffer);
    }
    m_buffer = buffer;
}

void XRenderBackend::setFailed(const QString& reason)
{
    qCCritical(KWIN_CORE) << "Creating the XRender backend failed: " << reason;
    m_failed = true;
}

void XRenderBackend::screenGeometryChanged(const QSize &size)
{
    Q_UNUSED(size)
}


//****************************************
// X11XRenderBackend
//****************************************
X11XRenderBackend::X11XRenderBackend()
    : XRenderBackend()
    , m_overlayWindow(new OverlayWindow())
    , m_front(XCB_RENDER_PICTURE_NONE)
    , m_format(0)
{
    init(true);
}

X11XRenderBackend::~X11XRenderBackend()
{
    if (m_front) {
        xcb_render_free_picture(connection(), m_front);
    }
    m_overlayWindow->destroy();
}

OverlayWindow* X11XRenderBackend::overlayWindow()
{
    return m_overlayWindow.data();
}

void X11XRenderBackend::showOverlay()
{
    if (m_overlayWindow->window())  // show the window only after the first pass, since
        m_overlayWindow->show();   // that pass may take long
}

void X11XRenderBackend::init(bool createOverlay)
{
    if (m_front != XCB_RENDER_PICTURE_NONE)
        xcb_render_free_picture(connection(), m_front);
    bool haveOverlay = createOverlay ? m_overlayWindow->create() : (m_overlayWindow->window() != XCB_WINDOW_NONE);
    if (haveOverlay) {
        m_overlayWindow->setup(XCB_WINDOW_NONE);
        ScopedCPointer<xcb_get_window_attributes_reply_t> attribs(xcb_get_window_attributes_reply(connection(),
            xcb_get_window_attributes_unchecked(connection(), m_overlayWindow->window()), NULL));
        if (!attribs) {
            setFailed("Failed getting window attributes for overlay window");
            return;
        }
        m_format = XRenderUtils::findPictFormat(attribs->visual);
        if (m_format == 0) {
            setFailed("Failed to find XRender format for overlay window");
            return;
        }
        m_front = xcb_generate_id(connection());
        xcb_render_create_picture(connection(), m_front, m_overlayWindow->window(), m_format, 0, NULL);
    } else {
        // create XRender picture for the root window
        m_format = XRenderUtils::findPictFormat(defaultScreen()->root_visual);
        if (m_format == 0) {
            setFailed("Failed to find XRender format for root window");
            return; // error
        }
        m_front = xcb_generate_id(connection());
        const uint32_t values[] = {XCB_SUBWINDOW_MODE_INCLUDE_INFERIORS};
        xcb_render_create_picture(connection(), m_front, rootWindow(), m_format, XCB_RENDER_CP_SUBWINDOW_MODE, values);
    }
    createBuffer();
}

void X11XRenderBackend::createBuffer()
{
    xcb_pixmap_t pixmap = xcb_generate_id(connection());
    xcb_create_pixmap(connection(), Xcb::defaultDepth(), pixmap, rootWindow(), displayWidth(), displayHeight());
    xcb_render_picture_t b = xcb_generate_id(connection());
    xcb_render_create_picture(connection(), b, pixmap, m_format, 0, NULL);
    xcb_free_pixmap(connection(), pixmap);   // The picture owns the pixmap now
    setBuffer(b);
}

void X11XRenderBackend::present(int mask, const QRegion &damage)
{
    if (mask & Scene::PAINT_SCREEN_REGION) {
        // Use the damage region as the clip region for the root window
        XFixesRegion frontRegion(damage);
        xcb_xfixes_set_picture_clip_region(connection(), m_front, frontRegion, 0, 0);
        // copy composed buffer to the root window
        xcb_xfixes_set_picture_clip_region(connection(), buffer(), XCB_XFIXES_REGION_NONE, 0, 0);
        xcb_render_composite(connection(), XCB_RENDER_PICT_OP_SRC, buffer(), XCB_RENDER_PICTURE_NONE,
                             m_front, 0, 0, 0, 0, 0, 0, displayWidth(), displayHeight());
        xcb_xfixes_set_picture_clip_region(connection(), m_front, XCB_XFIXES_REGION_NONE, 0, 0);
        xcb_flush(connection());
    } else {
        // copy composed buffer to the root window
        xcb_render_composite(connection(), XCB_RENDER_PICT_OP_SRC, buffer(), XCB_RENDER_PICTURE_NONE,
                             m_front, 0, 0, 0, 0, 0, 0, displayWidth(), displayHeight());
        xcb_flush(connection());
    }
}

void X11XRenderBackend::screenGeometryChanged(const QSize &size)
{
    Q_UNUSED(size)
    init(false);
}

bool X11XRenderBackend::usesOverlayWindow() const
{
    return true;
}

//****************************************
// WaylandXRenderBackend
//****************************************
#if HAVE_WAYLAND

WaylandXRenderBackend::WaylandXRenderBackend()
    : m_shm(new Xcb::Shm)
    , m_format(0)
{
    if (!m_shm->isValid()) {
        setFailed("Could not create XShm");
    }
    if (m_shm->pixmapFormat() != XCB_IMAGE_FORMAT_Z_PIXMAP) {
        setFailed("XShm pixmap does not have Z format");
    }
    init();
    connect(Wayland::WaylandBackend::self(), &Wayland::WaylandBackend::shellSurfaceSizeChanged,
            this, &WaylandXRenderBackend::createBuffer);
    connect(Wayland::WaylandBackend::self()->surface(), &KWayland::Client::Surface::frameRendered,
            Compositor::self(), &Compositor::bufferSwapComplete);
}

WaylandXRenderBackend::~WaylandXRenderBackend()
{
}

void WaylandXRenderBackend::init()
{
    m_format = XRenderUtils::findPictFormat(defaultScreen()->root_visual);
    if (m_format == 0) {
        setFailed("Failed to find XRender format for root window");
        return; // error
    }
    createBuffer();
}

void WaylandXRenderBackend::createBuffer()
{
    xcb_pixmap_t pixmap = xcb_generate_id(connection());
    const QSize &size = Wayland::WaylandBackend::self()->shellSurfaceSize();
    xcb_void_cookie_t cookie = xcb_shm_create_pixmap_checked(connection(), pixmap, rootWindow(),
                                                             size.width(), size.height(),
                                                             24, m_shm->segment(), 0);
    // let's check whether the pixmap got created
    ScopedCPointer<xcb_generic_error_t> error(xcb_request_check(connection(), cookie));
    if (error) {
        setFailed("Creating shm pixmap failed: " + QString::number(error->error_code));
        return;
    }

    // create the render picture
    xcb_render_picture_t b = xcb_generate_id(connection());
    xcb_render_create_picture(connection(), b, pixmap, m_format, 0, NULL);
    xcb_free_pixmap(connection(), pixmap);   // The picture owns the pixmap now
    setBuffer(b);

    qCDebug(KWIN_CORE) << "Offscreen shm pixmap created";
}

void WaylandXRenderBackend::present(int mask, const QRegion &damage)
{
    Q_UNUSED(mask)

    // we need to sync
    ScopedCPointer<xcb_get_input_focus_reply_t> sync(xcb_get_input_focus_reply(
        connection(), xcb_get_input_focus_unchecked(connection()), NULL));

    Wayland::WaylandBackend *wl = Wayland::WaylandBackend::self();
    const QSize &size = wl->shellSurfaceSize();
    auto buffer = wl->shmPool()->createBuffer(size, size.width() * 4, m_shm->buffer());
    if (!buffer) {
        qCDebug(KWIN_CORE) << "Did not get a buffer";
        return;
    }

    Compositor::self()->aboutToSwapBuffers();

    auto s = wl->surface();
    s->attachBuffer(buffer);
    s->damage(damage);
    s->commit();
}

bool WaylandXRenderBackend::usesOverlayWindow() const
{
    return false;
}

#endif

//****************************************
// SceneXrender
//****************************************
SceneXrender* SceneXrender::createScene()
{
    QScopedPointer<XRenderBackend> backend;
#if HAVE_WAYLAND
    if (kwinApp()->shouldUseWaylandForCompositing()) {
        backend.reset(new WaylandXRenderBackend);
        if (backend->isFailed()) {
            return NULL;
        }
        return new SceneXrender(backend.take());
    }
#endif
    backend.reset(new X11XRenderBackend);
    if (backend->isFailed()) {
        return NULL;
    }
    return new SceneXrender(backend.take());
}

SceneXrender::SceneXrender(XRenderBackend *backend)
    : Scene(Workspace::self())
    , m_backend(backend)
{
}

SceneXrender::~SceneXrender()
{
    SceneXrender::Window::cleanup();
    SceneXrender::EffectFrame::cleanup();
}

bool SceneXrender::initFailed() const
{
    return false;
}

// the entry point for painting
qint64 SceneXrender::paint(QRegion damage, ToplevelList toplevels)
{
    QElapsedTimer renderTimer;
    renderTimer.start();

    createStackingOrder(toplevels);

    int mask = 0;
    QRegion updateRegion, validRegion;
    paintScreen(&mask, damage, QRegion(), &updateRegion, &validRegion);

    m_backend->showOverlay();

    m_backend->present(mask, updateRegion);
    // do cleanup
    clearStackingOrder();

    return renderTimer.nsecsElapsed();
}

void SceneXrender::paintGenericScreen(int mask, ScreenPaintData data)
{
    screen_paint = data; // save, transformations will be done when painting windows
    Scene::paintGenericScreen(mask, data);
}

void SceneXrender::paintDesktop(int desktop, int mask, const QRegion &region, ScreenPaintData &data)
{
    PaintClipper::push(region);
    KWin::Scene::paintDesktop(desktop, mask, region, data);
    PaintClipper::pop(region);
}

// fill the screen background
void SceneXrender::paintBackground(QRegion region)
{
    xcb_render_color_t col = { 0, 0, 0, 0xffff }; // black
    const QVector<xcb_rectangle_t> &rects = Xcb::regionToRects(region);
    xcb_render_fill_rectangles(connection(), XCB_RENDER_PICT_OP_SRC, bufferPicture(), col, rects.count(), rects.data());
}

Scene::Window *SceneXrender::createWindow(Toplevel *toplevel)
{
    return new Window(toplevel, this);
}

Scene::EffectFrame *SceneXrender::createEffectFrame(EffectFrameImpl *frame)
{
    return new SceneXrender::EffectFrame(frame);
}

Shadow *SceneXrender::createShadow(Toplevel *toplevel)
{
    return new SceneXRenderShadow(toplevel);
}

Decoration::Renderer *SceneXrender::createDecorationRenderer(Decoration::DecoratedClientImpl* client)
{
    return new SceneXRenderDecorationRenderer(client);
}

//****************************************
// SceneXrender::Window
//****************************************

XRenderPicture *SceneXrender::Window::s_tempPicture = 0;
QRect SceneXrender::Window::temp_visibleRect;

SceneXrender::Window::Window(Toplevel* c, SceneXrender *scene)
    : Scene::Window(c)
    , m_scene(scene)
    , format(XRenderUtils::findPictFormat(c->visual()))
    , alpha_cached_opacity(0.0)
{
}

SceneXrender::Window::~Window()
{
    discardShape();
}

void SceneXrender::Window::cleanup()
{
    delete s_tempPicture;
    s_tempPicture = NULL;
}

// Maps window coordinates to screen coordinates
QRect SceneXrender::Window::mapToScreen(int mask, const WindowPaintData &data, const QRect &rect) const
{
    QRect r = rect;

    if (mask & PAINT_WINDOW_TRANSFORMED) {
        // Apply the window transformation
        r.moveTo(r.x() * data.xScale() + data.xTranslation(),
                 r.y() * data.yScale() + data.yTranslation());
        r.setWidth(r.width() * data.xScale());
        r.setHeight(r.height() * data.yScale());
    }

    // Move the rectangle to the screen position
    r.translate(x(), y());

    if (mask & PAINT_SCREEN_TRANSFORMED) {
        // Apply the screen transformation
        r.moveTo(r.x() * screen_paint.xScale() + screen_paint.xTranslation(),
                 r.y() * screen_paint.yScale() + screen_paint.yTranslation());
        r.setWidth(r.width() * screen_paint.xScale());
        r.setHeight(r.height() * screen_paint.yScale());
    }

    return r;
}

// Maps window coordinates to screen coordinates
QPoint SceneXrender::Window::mapToScreen(int mask, const WindowPaintData &data, const QPoint &point) const
{
    QPoint pt = point;

    if (mask & PAINT_WINDOW_TRANSFORMED) {
        // Apply the window transformation
        pt.rx() = pt.x() * data.xScale() + data.xTranslation();
        pt.ry() = pt.y() * data.yScale() + data.yTranslation();
    }

    // Move the point to the screen position
    pt += QPoint(x(), y());

    if (mask & PAINT_SCREEN_TRANSFORMED) {
        // Apply the screen transformation
        pt.rx() = pt.x() * screen_paint.xScale() + screen_paint.xTranslation();
        pt.ry() = pt.y() * screen_paint.yScale() + screen_paint.yTranslation();
    }

    return pt;
}

void SceneXrender::Window::prepareTempPixmap()
{
    const QSize oldSize = temp_visibleRect.size();
    temp_visibleRect = toplevel->visibleRect().translated(-toplevel->pos());
    if (s_tempPicture && (oldSize.width() < temp_visibleRect.width() || oldSize.height() < temp_visibleRect.height())) {
        delete s_tempPicture;
        s_tempPicture = NULL;
        scene_setXRenderOffscreenTarget(0); // invalidate, better crash than cause weird results for developers
    }
    if (!s_tempPicture) {
        xcb_pixmap_t pix = xcb_generate_id(connection());
        xcb_create_pixmap(connection(), 32, pix, rootWindow(), temp_visibleRect.width(), temp_visibleRect.height());
        s_tempPicture = new XRenderPicture(pix, 32);
        xcb_free_pixmap(connection(), pix);
    }
    const xcb_render_color_t transparent = {0, 0, 0, 0};
    const xcb_rectangle_t rect = {0, 0, uint16_t(temp_visibleRect.width()), uint16_t(temp_visibleRect.height())};
    xcb_render_fill_rectangles(connection(), XCB_RENDER_PICT_OP_SRC, *s_tempPicture, transparent, 1, &rect);
}

// paint the window
void SceneXrender::Window::performPaint(int mask, QRegion region, WindowPaintData data)
{
    setTransformedShape(QRegion());  // maybe nothing will be painted
    // check if there is something to paint
    bool opaque = isOpaque() && qFuzzyCompare(data.opacity(), 1.0);
    /* HACK: It seems this causes painting glitches, disable temporarily
    if (( mask & PAINT_WINDOW_OPAQUE ) ^ ( mask & PAINT_WINDOW_TRANSLUCENT ))
        { // We are only painting either opaque OR translucent windows, not both
        if ( mask & PAINT_WINDOW_OPAQUE && !opaque )
            return; // Only painting opaque and window is translucent
        if ( mask & PAINT_WINDOW_TRANSLUCENT && opaque )
            return; // Only painting translucent and window is opaque
        }*/
    // Intersect the clip region with the rectangle the window occupies on the screen
    if (!(mask & (PAINT_WINDOW_TRANSFORMED | PAINT_SCREEN_TRANSFORMED)))
        region &= toplevel->visibleRect();

    if (region.isEmpty())
        return;
    XRenderWindowPixmap *pixmap = windowPixmap<XRenderWindowPixmap>();
    if (!pixmap || !pixmap->isValid()) {
        return;
    }
    xcb_render_picture_t pic = pixmap->picture();
    if (pic == XCB_RENDER_PICTURE_NONE)   // The render format can be null for GL and/or Xv visuals
        return;
    toplevel->resetDamage();
    // set picture filter
    if (options->isXrenderSmoothScale()) { // only when forced, it's slow
        if (mask & PAINT_WINDOW_TRANSFORMED)
            filter = ImageFilterGood;
        else if (mask & PAINT_SCREEN_TRANSFORMED)
            filter = ImageFilterGood;
        else
            filter = ImageFilterFast;
    } else
        filter = ImageFilterFast;
    // do required transformations
    const QRect wr = mapToScreen(mask, data, QRect(0, 0, width(), height()));
    QRect cr = QRect(toplevel->clientPos(), toplevel->clientSize()); // Client rect (in the window)
    qreal xscale = 1;
    qreal yscale = 1;
    bool scaled = false;

    Client *client = dynamic_cast<Client*>(toplevel);
    Deleted *deleted = dynamic_cast<Deleted*>(toplevel);
    const QRect decorationRect = toplevel->decorationRect();
    if (((client && !client->noBorder()) || (deleted && !deleted->noBorder())) &&
                                                        true) {
        // decorated client
        transformed_shape = decorationRect;
        if (toplevel->shape()) {
            // "xeyes" + decoration
            transformed_shape -= cr;
            transformed_shape += shape();
        }
    } else {
        transformed_shape = shape();
    }
    if (toplevel->hasShadow())
        transformed_shape |= toplevel->shadow()->shadowRegion();

    xcb_render_transform_t xform = {
        DOUBLE_TO_FIXED(1), DOUBLE_TO_FIXED(0), DOUBLE_TO_FIXED(0),
        DOUBLE_TO_FIXED(0), DOUBLE_TO_FIXED(1), DOUBLE_TO_FIXED(0),
        DOUBLE_TO_FIXED(0), DOUBLE_TO_FIXED(0), DOUBLE_TO_FIXED(1)
    };
    static const xcb_render_transform_t identity = {
        DOUBLE_TO_FIXED(1), DOUBLE_TO_FIXED(0), DOUBLE_TO_FIXED(0),
        DOUBLE_TO_FIXED(0), DOUBLE_TO_FIXED(1), DOUBLE_TO_FIXED(0),
        DOUBLE_TO_FIXED(0), DOUBLE_TO_FIXED(0), DOUBLE_TO_FIXED(1)
    };

    if (mask & PAINT_WINDOW_TRANSFORMED) {
        xscale = data.xScale();
        yscale = data.yScale();
    }
    if (mask & PAINT_SCREEN_TRANSFORMED) {
        xscale *= screen_paint.xScale();
        yscale *= screen_paint.yScale();
    }
    if (!qFuzzyCompare(xscale, 1.0) || !qFuzzyCompare(yscale, 1.0)) {
        scaled = true;
        xform.matrix11 = DOUBLE_TO_FIXED(1.0 / xscale);
        xform.matrix22 = DOUBLE_TO_FIXED(1.0 / yscale);

        // transform the shape for clipping in paintTransformedScreen()
        QVector<QRect> rects = transformed_shape.rects();
        for (int i = 0; i < rects.count(); ++i) {
            QRect& r = rects[ i ];
            r.setRect(qRound(r.x() * xscale), qRound(r.y() * yscale),
                      qRound(r.width() * xscale), qRound(r.height() * yscale));
        }
        transformed_shape.setRects(rects.constData(), rects.count());
    }

    transformed_shape.translate(mapToScreen(mask, data, QPoint(0, 0)));
    PaintClipper pcreg(region);   // clip by the region to paint
    PaintClipper pc(transformed_shape);   // clip by window's shape

    const bool wantShadow = m_shadow && !m_shadow->shadowRegion().isEmpty();

    // In order to obtain a pixel perfect rescaling
    // we need to blit the window content togheter with
    // decorations in a temporary pixmap and scale
    // the temporary pixmap at the end.
    // We should do this only if there is scaling and
    // the window has border
    // This solves a number of glitches and on top of this
    // it optimizes painting quite a bit
    const bool blitInTempPixmap = xRenderOffscreen() || (data.crossFadeProgress() < 1.0 && !opaque) ||
                                 (scaled && (wantShadow || (client && !client->noBorder()) || (deleted && !deleted->noBorder())));

    xcb_render_picture_t renderTarget = m_scene->bufferPicture();
    if (blitInTempPixmap) {
        if (scene_xRenderOffscreenTarget()) {
            temp_visibleRect = toplevel->visibleRect().translated(-toplevel->pos());
            renderTarget = *scene_xRenderOffscreenTarget();
        } else {
            prepareTempPixmap();
            renderTarget = *s_tempPicture;
        }
    } else {
        xcb_render_set_picture_transform(connection(), pic, xform);
        if (filter == ImageFilterGood) {
            setPictureFilter(pic, KWin::Scene::ImageFilterGood);
        }

        //BEGIN OF STUPID RADEON HACK
        // This is needed to avoid hitting a fallback in the radeon driver.
        // The Render specification states that sampling pixels outside the
        // source picture results in alpha=0 pixels. This can be achieved by
        // setting the border color to transparent black, but since the border
        // color has the same format as the texture, it only works when the
        // texture has an alpha channel. So the driver falls back to software
        // when the repeat mode is RepeatNone, the picture has a non-identity
        // transformation matrix, and doesn't have an alpha channel.
        // Since we only scale the picture, we can work around this by setting
        // the repeat mode to RepeatPad.
        if (!window()->hasAlpha()) {
            const uint32_t values[] = {XCB_RENDER_REPEAT_PAD};
            xcb_render_change_picture(connection(), pic, XCB_RENDER_CP_REPEAT, values);
        }
        //END OF STUPID RADEON HACK
    }
#define MAP_RECT_TO_TARGET(_RECT_) \
        if (blitInTempPixmap) _RECT_.translate(-temp_visibleRect.topLeft()); else _RECT_ = mapToScreen(mask, data, _RECT_)

    //BEGIN deco preparations
    bool noBorder = true;
    xcb_render_picture_t left   = XCB_RENDER_PICTURE_NONE;
    xcb_render_picture_t top    = XCB_RENDER_PICTURE_NONE;
    xcb_render_picture_t right  = XCB_RENDER_PICTURE_NONE;
    xcb_render_picture_t bottom = XCB_RENDER_PICTURE_NONE;
    QRect dtr, dlr, drr, dbr;
    const SceneXRenderDecorationRenderer *renderer = nullptr;
    if (client) {
        if (client && !client->noBorder()) {
            if (client->isDecorated()) {
                SceneXRenderDecorationRenderer *r = static_cast<SceneXRenderDecorationRenderer*>(client->decoratedClient()->renderer());
                if (r) {
                    r->render();
                    renderer = r;
                }
            }
            noBorder = client->noBorder();
            client->layoutDecorationRects(dlr, dtr, drr, dbr);
        }
    }
    if (deleted && !deleted->noBorder()) {
        renderer = static_cast<const SceneXRenderDecorationRenderer*>(deleted->decorationRenderer());
        noBorder = deleted->noBorder();
        deleted->layoutDecorationRects(dlr, dtr, drr, dbr);
    }
    if (renderer) {
        left   = renderer->picture(SceneXRenderDecorationRenderer::DecorationPart::Left);
        top    = renderer->picture(SceneXRenderDecorationRenderer::DecorationPart::Top);
        right  = renderer->picture(SceneXRenderDecorationRenderer::DecorationPart::Right);
        bottom = renderer->picture(SceneXRenderDecorationRenderer::DecorationPart::Bottom);
    }
    if (!noBorder) {
        MAP_RECT_TO_TARGET(dtr);
        MAP_RECT_TO_TARGET(dlr);
        MAP_RECT_TO_TARGET(drr);
        MAP_RECT_TO_TARGET(dbr);
    }
    //END deco preparations

    //BEGIN shadow preparations
    QRect stlr, str, strr, srr, sbrr, sbr, sblr, slr;
    SceneXRenderShadow* m_xrenderShadow = static_cast<SceneXRenderShadow*>(m_shadow);

    if (wantShadow) {
        m_xrenderShadow->layoutShadowRects(str, strr, srr, sbrr, sbr, sblr, slr, stlr);
        MAP_RECT_TO_TARGET(stlr);
        MAP_RECT_TO_TARGET(str);
        MAP_RECT_TO_TARGET(strr);
        MAP_RECT_TO_TARGET(srr);
        MAP_RECT_TO_TARGET(sbrr);
        MAP_RECT_TO_TARGET(sbr);
        MAP_RECT_TO_TARGET(sblr);
        MAP_RECT_TO_TARGET(slr);
    }
    //BEGIN end preparations

    //BEGIN client preparations
    QRect dr = cr;
    if (blitInTempPixmap) {
        dr.translate(-temp_visibleRect.topLeft());
    } else {
        dr = mapToScreen(mask, data, dr); // Destination rect
        if (scaled) {
            cr.moveLeft(cr.x() * xscale);
            cr.moveTop(cr.y() * yscale);
        }
    }

    const int clientRenderOp = (opaque || blitInTempPixmap) ? XCB_RENDER_PICT_OP_SRC : XCB_RENDER_PICT_OP_OVER;
    //END client preparations

#undef MAP_RECT_TO_TARGET

    for (PaintClipper::Iterator iterator; !iterator.isDone(); iterator.next()) {

#define RENDER_SHADOW_TILE(_TILE_, _RECT_) \
xcb_render_composite(connection(), XCB_RENDER_PICT_OP_OVER, m_xrenderShadow->picture(SceneXRenderShadow::ShadowElement##_TILE_), \
                 shadowAlpha, renderTarget, 0, 0, 0, 0, _RECT_.x(), _RECT_.y(), _RECT_.width(), _RECT_.height())

        //shadow
        if (wantShadow) {
            xcb_render_picture_t shadowAlpha = XCB_RENDER_PICTURE_NONE;
            if (!opaque) {
                shadowAlpha = xRenderBlendPicture(data.opacity());
            }
            RENDER_SHADOW_TILE(TopLeft, stlr);
            RENDER_SHADOW_TILE(Top, str);
            RENDER_SHADOW_TILE(TopRight, strr);
            RENDER_SHADOW_TILE(Left, slr);
            RENDER_SHADOW_TILE(Right, srr);
            RENDER_SHADOW_TILE(BottomLeft, sblr);
            RENDER_SHADOW_TILE(Bottom, sbr);
            RENDER_SHADOW_TILE(BottomRight, sbrr);
        }
#undef RENDER_SHADOW_TILE

        // Paint the window contents
        if (!(client && client->isShade())) {
            xcb_render_picture_t clientAlpha = XCB_RENDER_PICTURE_NONE;
            if (!opaque) {
                clientAlpha = xRenderBlendPicture(data.opacity());
            }
            xcb_render_composite(connection(), clientRenderOp, pic, clientAlpha, renderTarget,
                                 cr.x(), cr.y(), 0, 0, dr.x(), dr.y(), dr.width(), dr.height());
            if (data.crossFadeProgress() < 1.0 && data.crossFadeProgress() > 0.0) {
                XRenderWindowPixmap *previous = previousWindowPixmap<XRenderWindowPixmap>();
                if (previous && previous != pixmap) {
                    static XRenderPicture cFadeAlpha(XCB_RENDER_PICTURE_NONE);
                    static xcb_render_color_t cFadeColor = {0, 0, 0, 0};
                    cFadeColor.alpha = uint16_t((1.0 - data.crossFadeProgress()) * 0xffff);
                    if (cFadeAlpha == XCB_RENDER_PICTURE_NONE) {
                        cFadeAlpha = xRenderFill(cFadeColor);
                    } else {
                        xcb_rectangle_t rect = {0, 0, 1, 1};
                        xcb_render_fill_rectangles(connection(), XCB_RENDER_PICT_OP_SRC, cFadeAlpha, cFadeColor , 1, &rect);
                    }
                    if (previous->size() != pixmap->size()) {
                        xcb_render_transform_t xform2 = {
                            DOUBLE_TO_FIXED(FIXED_TO_DOUBLE(xform.matrix11) * previous->size().width() / pixmap->size().width()), DOUBLE_TO_FIXED(0), DOUBLE_TO_FIXED(0),
                            DOUBLE_TO_FIXED(0), DOUBLE_TO_FIXED(FIXED_TO_DOUBLE(xform.matrix22) * previous->size().height() / pixmap->size().height()), DOUBLE_TO_FIXED(0),
                            DOUBLE_TO_FIXED(0), DOUBLE_TO_FIXED(0), DOUBLE_TO_FIXED(1)
                            };
                        xcb_render_set_picture_transform(connection(), previous->picture(), xform2);
                    }

                    xcb_render_composite(connection(), opaque ? XCB_RENDER_PICT_OP_OVER : XCB_RENDER_PICT_OP_ATOP,
                                         previous->picture(), cFadeAlpha, renderTarget,
                                         cr.x(), cr.y(), 0, 0, dr.x(), dr.y(), dr.width(), dr.height());

                    if (previous->size() != pixmap->size()) {
                        xcb_render_set_picture_transform(connection(), previous->picture(), identity);
                    }
                }
            }
            if (!opaque)
                transformed_shape = QRegion();
        }

        if (client || deleted) {
            if (!noBorder) {
                xcb_render_picture_t decorationAlpha = xRenderBlendPicture(data.opacity());
                auto renderDeco = [decorationAlpha, renderTarget](xcb_render_picture_t deco, const QRect &rect) {
                    if (deco == XCB_RENDER_PICTURE_NONE) {
                        return;
                    }
                    xcb_render_composite(connection(), XCB_RENDER_PICT_OP_OVER, deco, decorationAlpha, renderTarget,
                                         0, 0, 0, 0, rect.x(), rect.y(), rect.width(), rect.height());
                };
                renderDeco(top, dtr);
                renderDeco(left, dlr);
                renderDeco(right, drr);
                renderDeco(bottom, dbr);
            }
        }

        if (data.brightness() != 1.0) {
            // fake brightness change by overlaying black
            const float alpha = (1 - data.brightness()) * data.opacity();
            xcb_rectangle_t rect;
            if (blitInTempPixmap) {
                rect.x = -temp_visibleRect.left();
                rect.y = -temp_visibleRect.top();
                rect.width = width();
                rect.height = height();
            } else {
                rect.x = wr.x();
                rect.y = wr.y();
                rect.width = wr.width();
                rect.height = wr.height();
            }
            xcb_render_fill_rectangles(connection(), XCB_RENDER_PICT_OP_OVER, renderTarget,
                                       preMultiply(data.brightness() < 1.0 ? QColor(0,0,0,255*alpha) : QColor(255,255,255,-alpha*255)),
                                       1, &rect);
        }
        if (blitInTempPixmap) {
            const QRect r = mapToScreen(mask, data, temp_visibleRect);
            xcb_render_set_picture_transform(connection(), *s_tempPicture, xform);
            setPictureFilter(*s_tempPicture, filter);
            xcb_render_composite(connection(), XCB_RENDER_PICT_OP_OVER, *s_tempPicture,
                                 XCB_RENDER_PICTURE_NONE, m_scene->bufferPicture(),
                                 0, 0, 0, 0, r.x(), r.y(), r.width(), r.height());
            xcb_render_set_picture_transform(connection(), *s_tempPicture, identity);
        }
    }
    if (scaled && !blitInTempPixmap) {
        xcb_render_set_picture_transform(connection(), pic, identity);
        if (filter == ImageFilterGood)
            setPictureFilter(pic, KWin::Scene::ImageFilterFast);
        if (!window()->hasAlpha()) {
            const uint32_t values[] = {XCB_RENDER_REPEAT_NONE};
            xcb_render_change_picture(connection(), pic, XCB_RENDER_CP_REPEAT, values);
        }
    }
    if (xRenderOffscreen())
        scene_setXRenderOffscreenTarget(*s_tempPicture);
}

void SceneXrender::Window::setPictureFilter(xcb_render_picture_t pic, Scene::ImageFilterType filter)
{
    QByteArray filterName;
    switch (filter) {
    case KWin::Scene::ImageFilterFast:
        filterName = QByteArray("fast");
        break;
    case KWin::Scene::ImageFilterGood:
        filterName = QByteArray("good");
        break;
    }
    xcb_render_set_picture_filter(connection(), pic, filterName.length(), filterName.constData(), 0, NULL);
}

WindowPixmap* SceneXrender::Window::createWindowPixmap()
{
    return new XRenderWindowPixmap(this, format);
}

void SceneXrender::screenGeometryChanged(const QSize &size)
{
    Scene::screenGeometryChanged(size);
    m_backend->screenGeometryChanged(size);
}

//****************************************
// XRenderWindowPixmap
//****************************************

XRenderWindowPixmap::XRenderWindowPixmap(Scene::Window *window, xcb_render_pictformat_t format)
    : WindowPixmap(window)
    , m_picture(XCB_RENDER_PICTURE_NONE)
    , m_format(format)
{
}

XRenderWindowPixmap::~XRenderWindowPixmap()
{
    if (m_picture != XCB_RENDER_PICTURE_NONE) {
        xcb_render_free_picture(connection(), m_picture);
    }
}

void XRenderWindowPixmap::create()
{
    if (isValid()) {
        return;
    }
    KWin::WindowPixmap::create();
    if (!isValid()) {
        return;
    }
    m_picture = xcb_generate_id(connection());
    xcb_render_create_picture(connection(), m_picture, pixmap(), m_format, 0, NULL);
}

//****************************************
// SceneXrender::EffectFrame
//****************************************

XRenderPicture *SceneXrender::EffectFrame::s_effectFrameCircle = NULL;

SceneXrender::EffectFrame::EffectFrame(EffectFrameImpl* frame)
    : Scene::EffectFrame(frame)
{
    m_picture = NULL;
    m_textPicture = NULL;
    m_iconPicture = NULL;
    m_selectionPicture = NULL;
}

SceneXrender::EffectFrame::~EffectFrame()
{
    delete m_picture;
    delete m_textPicture;
    delete m_iconPicture;
    delete m_selectionPicture;
}

void SceneXrender::EffectFrame::cleanup()
{
    delete s_effectFrameCircle;
    s_effectFrameCircle = NULL;
}

void SceneXrender::EffectFrame::free()
{
    delete m_picture;
    m_picture = NULL;
    delete m_textPicture;
    m_textPicture = NULL;
    delete m_iconPicture;
    m_iconPicture = NULL;
    delete m_selectionPicture;
    m_selectionPicture = NULL;
}

void SceneXrender::EffectFrame::freeIconFrame()
{
    delete m_iconPicture;
    m_iconPicture = NULL;
}

void SceneXrender::EffectFrame::freeTextFrame()
{
    delete m_textPicture;
    m_textPicture = NULL;
}

void SceneXrender::EffectFrame::freeSelection()
{
    delete m_selectionPicture;
    m_selectionPicture = NULL;
}

void SceneXrender::EffectFrame::crossFadeIcon()
{
    // TODO: implement me
}

void SceneXrender::EffectFrame::crossFadeText()
{
    // TODO: implement me
}

void SceneXrender::EffectFrame::render(QRegion region, double opacity, double frameOpacity)
{
    Q_UNUSED(region)
    if (m_effectFrame->geometry().isEmpty()) {
        return; // Nothing to display
    }

    // Render the actual frame
    if (m_effectFrame->style() == EffectFrameUnstyled) {
        renderUnstyled(effects->xrenderBufferPicture(), m_effectFrame->geometry(), opacity * frameOpacity);
    } else if (m_effectFrame->style() == EffectFrameStyled) {
        if (!m_picture) { // Lazy creation
            updatePicture();
        }
        if (m_picture) {
            qreal left, top, right, bottom;
            m_effectFrame->frame().getMargins(left, top, right, bottom);   // m_geometry is the inner geometry
            QRect geom = m_effectFrame->geometry().adjusted(-left, -top, right, bottom);
            xcb_render_composite(connection(), XCB_RENDER_PICT_OP_OVER, *m_picture,
                                 XCB_RENDER_PICTURE_NONE, effects->xrenderBufferPicture(),
                                 0, 0, 0, 0, geom.x(), geom.y(), geom.width(), geom.height());
        }
    }
    if (!m_effectFrame->selection().isNull()) {
        if (!m_selectionPicture) { // Lazy creation
            const QPixmap pix = m_effectFrame->selectionFrame().framePixmap();
            if (!pix.isNull()) // don't try if there's no content
                m_selectionPicture = new XRenderPicture(m_effectFrame->selectionFrame().framePixmap().toImage());
        }
        if (m_selectionPicture) {
            const QRect geom = m_effectFrame->selection();
            xcb_render_composite(connection(), XCB_RENDER_PICT_OP_OVER, *m_selectionPicture,
                                 XCB_RENDER_PICTURE_NONE, effects->xrenderBufferPicture(),
                                 0, 0, 0, 0, geom.x(), geom.y(), geom.width(), geom.height());
        }
    }

    XRenderPicture fill = xRenderBlendPicture(opacity);

    // Render icon
    if (!m_effectFrame->icon().isNull() && !m_effectFrame->iconSize().isEmpty()) {
        QPoint topLeft(m_effectFrame->geometry().x(), m_effectFrame->geometry().center().y() - m_effectFrame->iconSize().height() / 2);

        if (!m_iconPicture)   // lazy creation
            m_iconPicture = new XRenderPicture(m_effectFrame->icon().pixmap(m_effectFrame->iconSize()).toImage());
        QRect geom = QRect(topLeft, m_effectFrame->iconSize());
        xcb_render_composite(connection(), XCB_RENDER_PICT_OP_OVER, *m_iconPicture, fill,
                             effects->xrenderBufferPicture(),
                             0, 0, 0, 0, geom.x(), geom.y(), geom.width(), geom.height());
    }

    // Render text
    if (!m_effectFrame->text().isEmpty()) {
        if (!m_textPicture) { // Lazy creation
            updateTextPicture();
        }
        xcb_render_composite(connection(), XCB_RENDER_PICT_OP_OVER, *m_textPicture, fill, effects->xrenderBufferPicture(),
                         0, 0, 0, 0, m_effectFrame->geometry().x(), m_effectFrame->geometry().y(),
                         m_effectFrame->geometry().width(), m_effectFrame->geometry().height());
    }
}

void SceneXrender::EffectFrame::renderUnstyled(xcb_render_picture_t pict, const QRect &rect, qreal opacity)
{
    const int roundness = 5;
    const QRect area = rect.adjusted(-roundness, -roundness, roundness, roundness);
    xcb_rectangle_t rects[3];
    // center
    rects[0].x = area.left();
    rects[0].y = area.top() + roundness;
    rects[0].width = area.width();
    rects[0].height = area.height() - roundness * 2;
    // top
    rects[1].x = area.left() + roundness;
    rects[1].y = area.top();
    rects[1].width = area.width() - roundness * 2;
    rects[1].height = roundness;
    // bottom
    rects[2].x = area.left() + roundness;
    rects[2].y = area.top() + area.height() - roundness;
    rects[2].width = area.width() - roundness * 2;
    rects[2].height = roundness;
    xcb_render_color_t color = {0, 0, 0, uint16_t(opacity * 0xffff)};
    xcb_render_fill_rectangles(connection(), XCB_RENDER_PICT_OP_OVER, pict, color, 3, rects);

    if (!s_effectFrameCircle) {
        // create the circle
        const int diameter = roundness * 2;
        xcb_pixmap_t pix = xcb_generate_id(connection());
        xcb_create_pixmap(connection(), 32, pix, rootWindow(), diameter, diameter);
        s_effectFrameCircle = new XRenderPicture(pix, 32);
        xcb_free_pixmap(connection(), pix);

        // clear it with transparent
        xcb_rectangle_t xrect = {0, 0, diameter, diameter};
        xcb_render_color_t tranparent = {0, 0, 0, 0};
        xcb_render_fill_rectangles(connection(), XCB_RENDER_PICT_OP_SRC, *s_effectFrameCircle, tranparent, 1, &xrect);

        static const int num_segments = 80;
        static const qreal theta = 2 * M_PI / qreal(num_segments);
        static const qreal c = qCos(theta); //precalculate the sine and cosine
        static const qreal s = qSin(theta);
        qreal t;

        qreal x = roundness;//we start at angle = 0
        qreal y = 0;

        QVector<xcb_render_pointfix_t> points;
        xcb_render_pointfix_t point;
        point.x = DOUBLE_TO_FIXED(roundness);
        point.y = DOUBLE_TO_FIXED(roundness);
        points << point;
        for (int ii = 0; ii <= num_segments; ++ii) {
            point.x = DOUBLE_TO_FIXED(x + roundness);
            point.y = DOUBLE_TO_FIXED(y + roundness);
            points << point;
            //apply the rotation matrix
            t = x;
            x = c * x - s * y;
            y = s * t + c * y;
        }
        XRenderPicture fill = xRenderFill(Qt::black);
        xcb_render_tri_fan(connection(), XCB_RENDER_PICT_OP_OVER, fill, *s_effectFrameCircle,
                        0, 0, 0, points.count(), points.constData());
    }
    // TODO: merge alpha mask with SceneXrender::Window::alphaMask
    // alpha mask
    xcb_pixmap_t pix = xcb_generate_id(connection());
    xcb_create_pixmap(connection(), 8, pix, rootWindow(), 1, 1);
    XRenderPicture alphaMask(pix, 8);
    xcb_free_pixmap(connection(), pix);
    const uint32_t values[] = {true};
    xcb_render_change_picture(connection(), alphaMask, XCB_RENDER_CP_REPEAT, values);
    color.alpha = int(opacity * 0xffff);
    xcb_rectangle_t xrect = {0, 0, 1, 1};
    xcb_render_fill_rectangles(connection(), XCB_RENDER_PICT_OP_SRC, alphaMask, color, 1, &xrect);

    // TODO: replace by lambda
#define RENDER_CIRCLE(srcX, srcY, destX, destY) \
xcb_render_composite(connection(), XCB_RENDER_PICT_OP_OVER, *s_effectFrameCircle, alphaMask, \
                     pict, srcX, srcY, 0, 0, destX, destY, roundness, roundness)

    RENDER_CIRCLE(0, 0, area.left(), area.top());
    RENDER_CIRCLE(0, roundness, area.left(), area.top() + area.height() - roundness);
    RENDER_CIRCLE(roundness, 0, area.left() + area.width() - roundness, area.top());
    RENDER_CIRCLE(roundness, roundness,
                  area.left() + area.width() - roundness, area.top() + area.height() - roundness);
#undef RENDER_CIRCLE
}

void SceneXrender::EffectFrame::updatePicture()
{
    delete m_picture;
    m_picture = 0L;
    if (m_effectFrame->style() == EffectFrameStyled) {
        const QPixmap pix = m_effectFrame->frame().framePixmap();
        if (!pix.isNull())
            m_picture = new XRenderPicture(pix.toImage());
    }
}

void SceneXrender::EffectFrame::updateTextPicture()
{
    // Mostly copied from SceneOpenGL::EffectFrame::updateTextTexture() above
    delete m_textPicture;
    m_textPicture = 0L;

    if (m_effectFrame->text().isEmpty()) {
        return;
    }

    // Determine position on texture to paint text
    QRect rect(QPoint(0, 0), m_effectFrame->geometry().size());
    if (!m_effectFrame->icon().isNull() && !m_effectFrame->iconSize().isEmpty()) {
        rect.setLeft(m_effectFrame->iconSize().width());
    }

    // If static size elide text as required
    QString text = m_effectFrame->text();
    if (m_effectFrame->isStatic()) {
        QFontMetrics metrics(m_effectFrame->text());
        text = metrics.elidedText(text, Qt::ElideRight, rect.width());
    }

    QPixmap pixmap(m_effectFrame->geometry().size());
    pixmap.fill(Qt::transparent);
    QPainter p(&pixmap);
    p.setFont(m_effectFrame->font());
    if (m_effectFrame->style() == EffectFrameStyled) {
        p.setPen(m_effectFrame->styledTextColor());
    } else {
        // TODO: What about no frame? Custom color setting required
        p.setPen(Qt::white);
    }
    p.drawText(rect, m_effectFrame->alignment(), text);
    p.end();
    m_textPicture = new XRenderPicture(pixmap.toImage());
}

SceneXRenderShadow::SceneXRenderShadow(Toplevel *toplevel)
    :Shadow(toplevel)
{
    for (int i=0; i<ShadowElementsCount; ++i) {
        m_pictures[i] = NULL;
    }
}

SceneXRenderShadow::~SceneXRenderShadow()
{
    for (int i=0; i<ShadowElementsCount; ++i) {
        delete m_pictures[i];
    }
}

void SceneXRenderShadow::layoutShadowRects(QRect& top, QRect& topRight,
                                           QRect& right, QRect& bottomRight,
                                           QRect& bottom, QRect& bottomLeft,
                                           QRect& left, QRect& topLeft)
{
    WindowQuadList quads = shadowQuads();

    if (quads.count() == 0) {
        return;
    }

    WindowQuad topQuad = quads.select(WindowQuadShadowTop)[0];
    WindowQuad topRightQuad = quads.select(WindowQuadShadowTopRight)[0];
    WindowQuad topLeftQuad = quads.select(WindowQuadShadowTopLeft)[0];
    WindowQuad leftQuad = quads.select(WindowQuadShadowLeft)[0];
    WindowQuad rightQuad = quads.select(WindowQuadShadowRight)[0];
    WindowQuad bottomQuad = quads.select(WindowQuadShadowBottom)[0];
    WindowQuad bottomRightQuad = quads.select(WindowQuadShadowBottomRight)[0];
    WindowQuad bottomLeftQuad = quads.select(WindowQuadShadowBottomLeft)[0];

    top = QRect(topQuad.left(), topQuad.top(), (topQuad.right()-topQuad.left()), (topQuad.bottom()-topQuad.top()));
    topLeft = QRect(topLeftQuad.left(), topLeftQuad.top(), (topLeftQuad.right()-topLeftQuad.left()), (topLeftQuad.bottom()-topLeftQuad.top()));
    topRight = QRect(topRightQuad.left(), topRightQuad.top(), (topRightQuad.right()-topRightQuad.left()), (topRightQuad.bottom()-topRightQuad.top()));
    left = QRect(leftQuad.left(), leftQuad.top(), (leftQuad.right()-leftQuad.left()), (leftQuad.bottom()-leftQuad.top()));
    right = QRect(rightQuad.left(), rightQuad.top(), (rightQuad.right()-rightQuad.left()), (rightQuad.bottom()-rightQuad.top()));
    bottom = QRect(bottomQuad.left(), bottomQuad.top(), (bottomQuad.right()-bottomQuad.left()), (bottomQuad.bottom()-bottomQuad.top()));
    bottomLeft = QRect(bottomLeftQuad.left(), bottomLeftQuad.top(), (bottomLeftQuad.right()-bottomLeftQuad.left()), (bottomLeftQuad.bottom()-bottomLeftQuad.top()));
    bottomRight = QRect(bottomRightQuad.left(), bottomRightQuad.top(), (bottomRightQuad.right()-bottomRightQuad.left()), (bottomRightQuad.bottom()-bottomRightQuad.top()));
}

void SceneXRenderShadow::buildQuads()
{
    Shadow::buildQuads();

    if (shadowQuads().count() == 0) {
        return;
    }

    QRect stlr, str, strr, srr, sbrr, sbr, sblr, slr;
    layoutShadowRects(str, strr, srr, sbrr, sbr, sblr, slr, stlr);
}

bool SceneXRenderShadow::prepareBackend()
{
    if (hasDecorationShadow()) {
        const QImage shadowImage = decorationShadowImage();
        QPainter p;
        int x = 0;
        int y = 0;
        auto drawElement = [this, &x, &y, &p, &shadowImage] (ShadowElements element) {
            QPixmap pix(elementSize(element));
            pix.fill(Qt::transparent);
            p.begin(&pix);
            p.drawImage(0, 0, shadowImage, x, y, pix.width(), pix.height());
            p.end();
            setShadowElement(pix, element);
            return pix.size();
        };
        x += drawElement(ShadowElementTopLeft).width();
        x += drawElement(ShadowElementTop).width();
        y += drawElement(ShadowElementTopRight).height();
        drawElement(ShadowElementRight);
        x = 0;
        y += drawElement(ShadowElementLeft).height();
        x += drawElement(ShadowElementBottomLeft).width();
        x += drawElement(ShadowElementBottom).width();
        drawElement(ShadowElementBottomRight).width();
    }
    const uint32_t values[] = {XCB_RENDER_REPEAT_NORMAL};
    for (int i=0; i<ShadowElementsCount; ++i) {
        delete m_pictures[i];
        m_pictures[i] = new XRenderPicture(shadowPixmap(ShadowElements(i)).toImage());
        xcb_render_change_picture(connection(), *m_pictures[i], XCB_RENDER_CP_REPEAT, values);
    }
    return true;
}

xcb_render_picture_t SceneXRenderShadow::picture(Shadow::ShadowElements element) const
{
    if (!m_pictures[element]) {
        return XCB_RENDER_PICTURE_NONE;
    }
    return *m_pictures[element];
}

SceneXRenderDecorationRenderer::SceneXRenderDecorationRenderer(Decoration::DecoratedClientImpl *client)
    : Renderer(client)
    , m_gc(XCB_NONE)
{
    connect(this, &Renderer::renderScheduled, client->client(), static_cast<void (Client::*)(const QRect&)>(&Client::addRepaint));
    for (int i = 0; i < int(DecorationPart::Count); ++i) {
        m_pixmaps[i] = XCB_PIXMAP_NONE;
        m_pictures[i] = nullptr;
    }
}

SceneXRenderDecorationRenderer::~SceneXRenderDecorationRenderer()
{
    for (int i = 0; i < int(DecorationPart::Count); ++i) {
        if (m_pixmaps[i] != XCB_PIXMAP_NONE) {
            xcb_free_pixmap(connection(), m_pixmaps[i]);
        }
        delete m_pictures[i];
    }
    if (m_gc != 0) {
        xcb_free_gc(connection(), m_gc);
    }
}

void SceneXRenderDecorationRenderer::render()
{
    QRegion scheduled = getScheduled();
    if (scheduled.isEmpty()) {
        return;
    }
    if (areImageSizesDirty()) {
        resizePixmaps();
        resetImageSizesDirty();
        scheduled = client()->client()->decorationRect();
    }

    const QRect top(QPoint(0, 0), m_sizes[int(DecorationPart::Top)]);
    const QRect left(QPoint(0, top.height()), m_sizes[int(DecorationPart::Left)]);
    const QRect right(QPoint(top.width() - m_sizes[int(DecorationPart::Right)].width(), top.height()), m_sizes[int(DecorationPart::Right)]);
    const QRect bottom(QPoint(0, left.y() + left.height()), m_sizes[int(DecorationPart::Bottom)]);

    xcb_connection_t *c = connection();
    if (m_gc == 0) {
        m_gc = xcb_generate_id(connection());
        xcb_create_gc(c, m_gc, m_pixmaps[int(DecorationPart::Top)], 0, nullptr);
    }
    auto renderPart = [this, c](const QRect &geo, const QPoint &offset, int index) {
        if (geo.isNull()) {
            return;
        }
        QImage image = renderToImage(geo);
        xcb_put_image(c, XCB_IMAGE_FORMAT_Z_PIXMAP, m_pixmaps[index], m_gc,
                      image.width(), image.height(), geo.x() - offset.x(), geo.y() - offset.y(), 0, 32,
                      image.byteCount(), image.constBits());
    };
    const QRect geometry = scheduled.boundingRect();
    renderPart(left.intersected(geometry),   left.topLeft(),   int(DecorationPart::Left));
    renderPart(top.intersected(geometry),    top.topLeft(),    int(DecorationPart::Top));
    renderPart(right.intersected(geometry),  right.topLeft(),  int(DecorationPart::Right));
    renderPart(bottom.intersected(geometry), bottom.topLeft(), int(DecorationPart::Bottom));
    xcb_flush(c);
}

void SceneXRenderDecorationRenderer::resizePixmaps()
{
    QRect left, top, right, bottom;
    client()->client()->layoutDecorationRects(left, top, right, bottom);

    xcb_connection_t *c = connection();
    auto checkAndCreate = [this, c](int border, const QRect &rect) {
        const QSize size = rect.size();
        if (m_sizes[border] != size) {
            m_sizes[border] = size;
            if (m_pixmaps[border] != XCB_PIXMAP_NONE) {
                xcb_free_pixmap(c, m_pixmaps[border]);
            }
            delete m_pictures[border];
            if (!size.isEmpty()) {
                m_pixmaps[border] = xcb_generate_id(connection());
                xcb_create_pixmap(connection(), 32, m_pixmaps[border], rootWindow(), size.width(), size.height());
                m_pictures[border] = new XRenderPicture(m_pixmaps[border], 32);
            } else {
                m_pixmaps[border] = XCB_PIXMAP_NONE;
                m_pictures[border] = nullptr;
            }
        }
        if (!m_pictures[border]) {
            return;
        }
        // fill transparent
        xcb_rectangle_t r = {0, 0, uint16_t(size.width()), uint16_t(size.height())};
        xcb_render_fill_rectangles(connection(), XCB_RENDER_PICT_OP_SRC, *m_pictures[border], preMultiply(Qt::transparent), 1, &r);
    };

    checkAndCreate(int(DecorationPart::Left), left);
    checkAndCreate(int(DecorationPart::Top), top);
    checkAndCreate(int(DecorationPart::Right), right);
    checkAndCreate(int(DecorationPart::Bottom), bottom);
}

xcb_render_picture_t SceneXRenderDecorationRenderer::picture(SceneXRenderDecorationRenderer::DecorationPart part) const
{
    Q_ASSERT(part != DecorationPart::Count);
    XRenderPicture *picture = m_pictures[int(part)];
    if (!picture) {
        return XCB_RENDER_PICTURE_NONE;
    }
    return *picture;
}

void SceneXRenderDecorationRenderer::reparent(Deleted *deleted)
{
    render();
    Renderer::reparent(deleted);
}

#undef DOUBLE_TO_FIXED
#undef FIXED_TO_DOUBLE

} // namespace
#endif