Fix wrong transform when applying multiple QGraphicsEffects.

3 files changed, 27 insertions, 17 deletions

diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index 47f8a90..7a53598 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -10021,10 +10021,11 @@ QRectF QGraphicsItemEffectSourcePrivate::boundingRect(Qt::CoordinateSystem syste
     if (!item->d_ptr->children.isEmpty())
         rect |= item->childrenBoundingRect();
 
-    if (info && deviceCoordinates) {
-        Q_ASSERT(info->transformPtr);
-        rect = info->transformPtr->mapRect(rect);
+    if (deviceCoordinates) {
+        Q_ASSERT(info->painter);
+        rect = info->painter->worldTransform().mapRect(rect);
     }
+
     return rect;
 }
 
@@ -10039,11 +10040,13 @@ void QGraphicsItemEffectSourcePrivate::draw(QPainter *painter)
     QGraphicsScenePrivate *scened = item->d_ptr->scene->d_func();
     if (painter == info->painter) {
         scened->draw(item, painter, info->viewTransform, info->transformPtr, info->exposedRegion,
-                     info->widget, info->opacity, 0, info->wasDirtySceneTransform,
+                     info->widget, info->opacity, info->effectTransform, info->wasDirtySceneTransform,
                      info->drawItem);
     } else {
         QTransform effectTransform = painter->worldTransform();
-        effectTransform *= info->transformPtr->inverted();
+        effectTransform *= info->painter->worldTransform().inverted();
+        if (info->effectTransform)
+            effectTransform *= *info->effectTransform;
         scened->draw(item, painter, info->viewTransform, info->transformPtr, info->exposedRegion,
                      info->widget, info->opacity, &effectTransform, info->wasDirtySceneTransform,
                      info->drawItem);
@@ -10097,26 +10100,28 @@ QPixmap QGraphicsItemEffectSourcePrivate::pixmap(Qt::CoordinateSystem system, QP
     QPainter pixmapPainter(&pixmap);
     pixmapPainter.setRenderHints(info ? info->painter->renderHints() : QPainter::TextAntialiasing);
 
-    const QTransform translateTransform = QTransform::fromTranslate(-effectRect.x(),
-                                                                    -effectRect.y());
+    QTransform effectTransform = QTransform::fromTranslate(-effectRect.x(), -effectRect.y());
+    if (deviceCoordinates && info->effectTransform)
+        effectTransform *= *info->effectTransform;
+
     if (!info) {
         // Logical coordinates without info.
         QTransform sceneTransform = item->sceneTransform();
-        QTransform effectTransform = sceneTransform.inverted();
-        effectTransform *= translateTransform;
+        QTransform newEffectTransform = sceneTransform.inverted();
+        newEffectTransform *= effectTransform;
         scened->draw(item, &pixmapPainter, 0, &sceneTransform, 0, 0, qreal(1.0),
-                     &effectTransform, false, true);
+                     &newEffectTransform, false, true);
     } else if (deviceCoordinates) {
         // Device coordinates with info.
         scened->draw(item, &pixmapPainter, info->viewTransform, info->transformPtr, info->exposedRegion,
-                     info->widget, info->opacity, &translateTransform, info->wasDirtySceneTransform,
+                     info->widget, info->opacity, &effectTransform, info->wasDirtySceneTransform,
                      info->drawItem);
     } else {
         // Item coordinates with info.
-        QTransform effectTransform = info->transformPtr->inverted();
-        effectTransform *= translateTransform;
+        QTransform newEffectTransform = info->transformPtr->inverted();
+        newEffectTransform *= effectTransform;
         scened->draw(item, &pixmapPainter, info->viewTransform, info->transformPtr, info->exposedRegion,
-                     info->widget, info->opacity, &effectTransform, info->wasDirtySceneTransform,
+                     info->widget, info->opacity, &newEffectTransform, info->wasDirtySceneTransform,
                      info->drawItem);
     }
     return pixmap;
diff --git a/src/gui/graphicsview/qgraphicsitem_p.h b/src/gui/graphicsview/qgraphicsitem_p.h
index 76c9dab..0d6946f 100644
--- a/src/gui/graphicsview/qgraphicsitem_p.h
+++ b/src/gui/graphicsview/qgraphicsitem_p.h
@@ -517,14 +517,16 @@ struct QGraphicsItemPrivate::TransformData {
 struct QGraphicsItemPaintInfo
 {
     inline QGraphicsItemPaintInfo(const QTransform *const xform1, const QTransform *const xform2,
+                                  const QTransform *const xform3,
                                   QRegion *r, QWidget *w, QStyleOptionGraphicsItem *opt,
                                   QPainter *p, qreal o, bool b1, bool b2)
-        : viewTransform(xform1), transformPtr(xform2), exposedRegion(r), widget(w),
+        : viewTransform(xform1), transformPtr(xform2), effectTransform(xform3), exposedRegion(r), widget(w),
           option(opt), painter(p), opacity(o), wasDirtySceneTransform(b1), drawItem(b2)
     {}
 
     const QTransform *viewTransform;
     const QTransform *transformPtr;
+    const QTransform *effectTransform;
     QRegion *exposedRegion;
     QWidget *widget;
     QStyleOptionGraphicsItem *option;
diff --git a/src/gui/graphicsview/qgraphicsscene.cpp b/src/gui/graphicsview/qgraphicsscene.cpp
index c898a3e..5f214c9 100644
--- a/src/gui/graphicsview/qgraphicsscene.cpp
+++ b/src/gui/graphicsview/qgraphicsscene.cpp
@@ -4348,14 +4348,17 @@ void QGraphicsScenePrivate::drawSubtreeRecursive(QGraphicsItem *item, QPainter *
 
     if (item->d_ptr->graphicsEffect && item->d_ptr->graphicsEffect->isEnabled()) {
         ENSURE_TRANSFORM_PTR;
-        QGraphicsItemPaintInfo info(viewTransform, transformPtr, exposedRegion, widget, &styleOptionTmp,
+        QGraphicsItemPaintInfo info(viewTransform, transformPtr, effectTransform, exposedRegion, widget, &styleOptionTmp,
                                     painter, opacity, wasDirtyParentSceneTransform, drawItem);
         QGraphicsEffectSource *source = item->d_ptr->graphicsEffect->d_func()->source;
         QGraphicsItemEffectSourcePrivate *sourced = static_cast<QGraphicsItemEffectSourcePrivate *>
                                                     (source->d_func());
         sourced->info = &info;
         const QTransform restoreTransform = painter->worldTransform();
-        painter->setWorldTransform(*transformPtr);
+        if (effectTransform)
+            painter->setWorldTransform(*transformPtr * *effectTransform);
+        else
+            painter->setWorldTransform(*transformPtr);
         item->d_ptr->graphicsEffect->draw(painter, source);
         painter->setWorldTransform(restoreTransform);
         sourced->info = 0;