summaryrefslogtreecommitdiffstats
path: root/gfx/layers/apz/src/SampledAPZCState.cpp
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
commit36d22d82aa202bb199967e9512281e9a53db42c9 (patch)
tree105e8c98ddea1c1e4784a60a5a6410fa416be2de /gfx/layers/apz/src/SampledAPZCState.cpp
parentInitial commit. (diff)
downloadfirefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz
firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip
Adding upstream version 115.7.0esr.upstream/115.7.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'gfx/layers/apz/src/SampledAPZCState.cpp')
-rw-r--r--gfx/layers/apz/src/SampledAPZCState.cpp111
1 files changed, 111 insertions, 0 deletions
diff --git a/gfx/layers/apz/src/SampledAPZCState.cpp b/gfx/layers/apz/src/SampledAPZCState.cpp
new file mode 100644
index 0000000000..712a46a3b1
--- /dev/null
+++ b/gfx/layers/apz/src/SampledAPZCState.cpp
@@ -0,0 +1,111 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "SampledAPZCState.h"
+#include "APZUtils.h"
+
+namespace mozilla {
+namespace layers {
+
+SampledAPZCState::SampledAPZCState() {}
+
+SampledAPZCState::SampledAPZCState(const FrameMetrics& aMetrics)
+ : mLayoutViewport(aMetrics.GetLayoutViewport()),
+ mVisualScrollOffset(aMetrics.GetVisualScrollOffset()),
+ mZoom(aMetrics.GetZoom()) {
+ RemoveFractionalAsyncDelta();
+}
+
+SampledAPZCState::SampledAPZCState(const FrameMetrics& aMetrics,
+ Maybe<CompositionPayload>&& aPayload,
+ APZScrollGeneration aGeneration)
+ : mLayoutViewport(aMetrics.GetLayoutViewport()),
+ mVisualScrollOffset(aMetrics.GetVisualScrollOffset()),
+ mZoom(aMetrics.GetZoom()),
+ mScrollPayload(std::move(aPayload)),
+ mGeneration(aGeneration) {
+ RemoveFractionalAsyncDelta();
+}
+
+bool SampledAPZCState::operator==(const SampledAPZCState& aOther) const {
+ // The payload doesn't factor into equality, that just comes along for
+ // the ride.
+ return mLayoutViewport.IsEqualEdges(aOther.mLayoutViewport) &&
+ mVisualScrollOffset == aOther.mVisualScrollOffset &&
+ mZoom == aOther.mZoom;
+}
+
+bool SampledAPZCState::operator!=(const SampledAPZCState& aOther) const {
+ return !(*this == aOther);
+}
+
+Maybe<CompositionPayload> SampledAPZCState::TakeScrollPayload() {
+ return std::move(mScrollPayload);
+}
+
+void SampledAPZCState::UpdateScrollProperties(const FrameMetrics& aMetrics) {
+ mLayoutViewport = aMetrics.GetLayoutViewport();
+ mVisualScrollOffset = aMetrics.GetVisualScrollOffset();
+}
+
+void SampledAPZCState::UpdateScrollPropertiesWithRelativeDelta(
+ const FrameMetrics& aMetrics, const CSSPoint& aRelativeDelta) {
+ mVisualScrollOffset += aRelativeDelta;
+ KeepLayoutViewportEnclosingVisualViewport(aMetrics);
+}
+
+void SampledAPZCState::UpdateZoomProperties(const FrameMetrics& aMetrics) {
+ mZoom = aMetrics.GetZoom();
+}
+
+void SampledAPZCState::ClampVisualScrollOffset(const FrameMetrics& aMetrics) {
+ // Make sure that we use the local mZoom to do these calculations, because the
+ // one on aMetrics might be newer.
+ CSSRect scrollRange = FrameMetrics::CalculateScrollRange(
+ aMetrics.GetScrollableRect(), aMetrics.GetCompositionBounds(), mZoom);
+ mVisualScrollOffset = scrollRange.ClampPoint(mVisualScrollOffset);
+
+ KeepLayoutViewportEnclosingVisualViewport(aMetrics);
+}
+
+void SampledAPZCState::ZoomBy(float aScale) { mZoom.scale *= aScale; }
+
+void SampledAPZCState::RemoveFractionalAsyncDelta() {
+ // This function is a performance hack. With non-WebRender, having small
+ // fractional deltas between the layout offset and scroll offset on
+ // container layers can trigger the creation of a temporary surface during
+ // composition, because it produces a non-integer translation that doesn't
+ // play well with layer clips. So we detect the case where the delta is
+ // uselessly small (0.01 parentlayer pixels or less) and tweak the sampled
+ // scroll offset to eliminate it. By doing this here at sample time rather
+ // than elsewhere in the pipeline we are least likely to break assumptions
+ // and invariants elsewhere in the code, since sampling effectively takes
+ // a snapshot of APZ state (decoupling it from APZ assumptions) and provides
+ // it as an input to the compositor (so all compositor state should be
+ // internally consistent based on this input).
+ if (mLayoutViewport.TopLeft() == mVisualScrollOffset) {
+ return;
+ }
+ const ParentLayerCoord EPSILON = 0.01;
+ ParentLayerPoint paintedOffset = mLayoutViewport.TopLeft() * mZoom;
+ ParentLayerPoint asyncOffset = mVisualScrollOffset * mZoom;
+ if (FuzzyEqualsAdditive(paintedOffset.x, asyncOffset.x, EPSILON) &&
+ FuzzyEqualsAdditive(paintedOffset.y, asyncOffset.y, EPSILON)) {
+ mVisualScrollOffset = mLayoutViewport.TopLeft();
+ }
+}
+
+void SampledAPZCState::KeepLayoutViewportEnclosingVisualViewport(
+ const FrameMetrics& aMetrics) {
+ FrameMetrics::KeepLayoutViewportEnclosingVisualViewport(
+ CSSRect(mVisualScrollOffset,
+ FrameMetrics::CalculateCompositedSizeInCssPixels(
+ aMetrics.GetCompositionBounds(), mZoom)),
+ aMetrics.GetScrollableRect(), mLayoutViewport);
+}
+
+} // namespace layers
+} // namespace mozilla