void KisCoordinatesConverterTest::testRotation()
{
    KisImageSP image;
    KisCoordinatesConverter converter;
    initImage(&image, &converter);

    QSize widgetSize(1000,500);
    QRectF testRect(800, 100, 300, 300);

    converter.setImage(image);
    converter.setDocumentOffset(QPoint(0,0));
    converter.setCanvasWidgetSize(widgetSize);

    converter.rotate(converter.widgetCenterPoint(), 30);
    converter.setZoom(1.);

    QTransform viewportToWidget = converter.viewportToWidgetTransform();

    QRectF boundingRect = viewportToWidget.mapRect(testRect);
    QRectF directRect = converter.viewportToWidget(testRect);

    QCOMPARE(boundingRect, directRect);

    QRectF referenceRect(QPointF(742.82,53.5898), QSizeF(409.808,409.808));

#define FUZZY(a,b) ((a)-(b) < 0.01)

    QVERIFY(FUZZY(boundingRect.top(), referenceRect.top()));
    QVERIFY(FUZZY(boundingRect.left(), referenceRect.left()));
    QVERIFY(FUZZY(boundingRect.width(), referenceRect.width()));
    QVERIFY(FUZZY(boundingRect.height(), referenceRect.height()));
}
void KisCoordinatesConverterTest::testConsistency()
{
    KisImageSP image;
    KisCoordinatesConverter converter;
    initImage(&image, &converter);

    converter.setImage(image);
    converter.setDocumentOffset(QPoint(20,30));
    converter.setCanvasWidgetSize(QSize(500,500));

    QRectF testRect(100,100,100,100);
    QTransform imageToWidget;
    QTransform documentToWidget;
    QTransform viewportToWidget;

    converter.setZoom(0.5);

    imageToWidget = converter.imageToWidgetTransform();
    documentToWidget = converter.documentToWidgetTransform();
    viewportToWidget = converter.viewportToWidgetTransform();

    QRectF fromImage = converter.viewportToWidget(converter.imageToViewport(testRect));
    QRectF fromDocument = converter.documentToWidget(testRect);
    QRectF fromViewport = converter.viewportToWidget(testRect);

    CHECK_TRANSFORM(imageToWidget, testRect, fromImage);
    CHECK_TRANSFORM(documentToWidget, testRect, fromDocument);
    CHECK_TRANSFORM(viewportToWidget, testRect, fromViewport);
}
void KisCoordinatesConverterTest::testTransformations()
{
    KisImageSP image;
    KisCoordinatesConverter converter;
    initImage(&image, &converter);

    converter.setImage(image);
    converter.setDocumentOffset(QPoint(20,30));
    converter.setCanvasWidgetSize(QSize(500,500));

    QRectF testRect(100,100,100,100);
    QTransform imageToWidget;
    QTransform documentToWidget;
    QTransform flakeToWidget;
    QTransform viewportToWidget;

    converter.setZoom(1.);

    imageToWidget = converter.imageToWidgetTransform();
    documentToWidget = converter.documentToWidgetTransform();
    flakeToWidget = converter.flakeToWidgetTransform();
    viewportToWidget = converter.viewportToWidgetTransform();

    CHECK_TRANSFORM(imageToWidget, testRect, QRectF(80,70,100,100));
    CHECK_TRANSFORM(documentToWidget, testRect, QRectF(9980,9970,10000,10000));
    CHECK_TRANSFORM(flakeToWidget, testRect, QRectF(80,70,100,100));
    CHECK_TRANSFORM(viewportToWidget, testRect, QRectF(100,100,100,100));

    converter.setZoom(0.5);

    imageToWidget = converter.imageToWidgetTransform();
    documentToWidget = converter.documentToWidgetTransform();
    flakeToWidget = converter.flakeToWidgetTransform();
    viewportToWidget = converter.viewportToWidgetTransform();

    CHECK_TRANSFORM(imageToWidget, testRect, QRectF(30,20,50,50));
    CHECK_TRANSFORM(documentToWidget, testRect, QRectF(4980,4970,5000,5000));
    CHECK_TRANSFORM(flakeToWidget, testRect, QRectF(80,70,100,100));
    CHECK_TRANSFORM(viewportToWidget, testRect, QRectF(100,100,100,100));
}
void KisQPainterCanvas::paintEvent(QPaintEvent * ev)
{
    KisImageWSP image = canvas()->image();
    if (image == 0) return;

    setAutoFillBackground(false);

    if (m_buffer.size() != size()) {
        m_buffer = QImage(size(), QImage::Format_ARGB32_Premultiplied);
    }


    QPainter gc(&m_buffer);

    // we double buffer, so we paint on an image first, then from the image onto the canvas,
    // so copy the clip region since otherwise we're filling the whole buffer every time with
    // the background color _and_ the transparent squares.
    gc.setClipRegion(ev->region());

    KisCoordinatesConverter *converter = coordinatesConverter();
    QTransform imageTransform = converter->viewportToWidgetTransform();

    gc.save();

    gc.setCompositionMode(QPainter::CompositionMode_Source);
    gc.fillRect(QRect(QPoint(0, 0), size()), borderColor());

    QTransform checkersTransform;
    QPointF brushOrigin;
    QPolygonF polygon;

    converter->getQPainterCheckersInfo(&checkersTransform, &brushOrigin, &polygon);
    gc.setPen(Qt::NoPen);
    gc.setBrush(m_d->checkBrush);
    gc.setBrushOrigin(brushOrigin);
    gc.setTransform(checkersTransform);
    gc.drawPolygon(polygon);

    gc.setTransform(imageTransform);
    gc.setRenderHint(QPainter::SmoothPixmapTransform, true);

    QRectF viewportRect = converter->widgetToViewport(ev->rect());

    gc.setCompositionMode(QPainter::CompositionMode_SourceOver);
    gc.drawImage(viewportRect, m_d->prescaledProjection->prescaledQImage(),
                 viewportRect);

    gc.restore();


#ifdef DEBUG_REPAINT
    QColor color = QColor(random() % 255, random() % 255, random() % 255, 150);
    gc.fillRect(ev->rect(), color);
#endif

    drawDecorations(gc, ev->rect());
    gc.end();

    QPainter painter(this);
    painter.drawImage(ev->rect(), m_buffer, ev->rect());
}