[WPE][GTK] visible rect in case animations is not correctly calculated

https://bugs.webkit.org/show_bug.cgi?id=280612

Reviewed by Miguel Gomez.

For animations starting partially outside the viewport were not fully rendered when
the first frame entered the visible area. This caused incomplete or cut-off frames
during the initial stages of the animation. The issue was more noticeable on low-end
devices(RPi) or during slow-motion or frame-by-frame analysis of the recordings on x86.

With this change the visible rect is extended with the elements which are currently
not fully visible but they will be in a future bacause of animations.

* Source/WebCore/platform/graphics/texmap/coordinated/CoordinatedGraphicsLayer.cpp:
(WebCore::CoordinatedGraphicsLayer::transformedVisibleRectIncludingFuture):
(WebCore::CoordinatedGraphicsLayer::updateContentBuffers):
(WebCore::CoordinatedGraphicsLayer::computeTransformedVisibleRect):
* Source/WebCore/platform/graphics/texmap/coordinated/CoordinatedGraphicsLayer.h:

Source/WebCore/platform/graphics/texmap/coordinated/CoordinatedGraphicsLayer.cpp

@@ -1113,6 +1113,18 @@ IntRect CoordinatedGraphicsLayer::transformedVisibleRect()
     return enclosingIntRect(rect);
 }
 
+IntRect CoordinatedGraphicsLayer::transformedVisibleRectIncludingFuture()
+{
+    auto visibleRectIncludingFuture = transformedVisibleRect();
+    if (m_cachedInverseTransform != m_cachedFutureInverseTransform) {
+        FloatRect rect = m_cachedFutureInverseTransform.clampedBoundsOfProjectedQuad(FloatQuad(m_coordinator->visibleContentsRect()));
+        clampToContentsRectIfRectIsInfinite(rect, size());
+        visibleRectIncludingFuture.unite(enclosingIntRect(rect));
+    }
+
+    return visibleRectIncludingFuture;
+}
+
 void CoordinatedGraphicsLayer::requestBackingStoreUpdate()
 {
     setNeedsVisibleRectAdjustment();
@@ -1185,7 +1197,7 @@ void CoordinatedGraphicsLayer::updateContentBuffers()
 
     if (m_pendingVisibleRectAdjustment) {
         m_pendingVisibleRectAdjustment = false;
-        layerState.mainBackingStore->createTilesIfNeeded(transformedVisibleRect(), IntRect(0, 0, m_size.width(), m_size.height()));
+        layerState.mainBackingStore->createTilesIfNeeded(transformedVisibleRectIncludingFuture(), IntRect(0, 0, m_size.width(), m_size.height()));
     }
 
     if (is<CoordinatedAnimatedBackingStoreClient>(m_nicosia.animatedBackingStoreClient)) {
@@ -1375,8 +1387,13 @@ void CoordinatedGraphicsLayer::computeTransformedVisibleRect()
 
     m_shouldUpdateVisibleRect = false;
     TransformationMatrix currentTransform = transform();
-    if (m_movingVisibleRect)
+    TransformationMatrix futureTransform = currentTransform;
+    if (m_movingVisibleRect) {
         client().getCurrentTransform(this, currentTransform);
+        Nicosia::Animation::ApplicationResult futureApplicationResults;
+        m_animations.applyKeepingInternalState(futureApplicationResults, MonotonicTime::now() + 300_ms);
+        futureTransform = futureApplicationResults.transform.value_or(currentTransform);
+    }
     m_layerTransform.setLocalTransform(currentTransform);
 
     m_layerTransform.setAnchorPoint(m_adjustedAnchorPoint);
@@ -1389,6 +1406,17 @@ void CoordinatedGraphicsLayer::computeTransformedVisibleRect()
 
     m_cachedInverseTransform = m_layerTransform.combined().inverse().value_or(TransformationMatrix());
 
+    m_layerFutureTransform = m_layerTransform;
+    m_cachedFutureInverseTransform = m_cachedInverseTransform;
+
+    CoordinatedGraphicsLayer* parentLayer = downcast<CoordinatedGraphicsLayer>(parent());
+
+    if (currentTransform != futureTransform || (parentLayer && parentLayer->m_layerTransform.combinedForChildren() != parentLayer->m_layerFutureTransform.combinedForChildren())) {
+        m_layerFutureTransform.setLocalTransform(futureTransform);
+        m_layerFutureTransform.combineTransforms(parentLayer ? parentLayer->m_layerFutureTransform.combinedForChildren() : TransformationMatrix());
+        m_cachedFutureInverseTransform = m_layerFutureTransform.combined().inverse().value_or(TransformationMatrix());
+    }
+
     // The combined transform will be used in tiledBackingStoreVisibleRect.
     setNeedsVisibleRectAdjustment();
 }

Source/WebCore/platform/graphics/texmap/coordinated/CoordinatedGraphicsLayer.h

@@ -134,6 +134,7 @@ class WEBCORE_EXPORT CoordinatedGraphicsLayer : public GraphicsLayer {
     void computePixelAlignment(FloatPoint& position, FloatSize&, FloatPoint3D& anchorPoint, FloatSize& alignmentOffset);
 
     IntRect transformedVisibleRect();
+    IntRect transformedVisibleRectIncludingFuture();
 
     void invalidateCoordinator();
     void setCoordinatorIncludingSubLayersIfNeeded(CoordinatedGraphicsLayerClient*);
@@ -211,7 +212,9 @@ class WEBCORE_EXPORT CoordinatedGraphicsLayer : public GraphicsLayer {
 
     Nicosia::PlatformLayer::LayerID m_id;
     GraphicsLayerTransform m_layerTransform;
+    GraphicsLayerTransform m_layerFutureTransform;
     TransformationMatrix m_cachedInverseTransform;
+    TransformationMatrix m_cachedFutureInverseTransform;
     FloatSize m_pixelAlignmentOffset;
     FloatSize m_adjustedSize;
     FloatPoint m_adjustedPosition;