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-rw-r--r--layout/painting/DisplayItemClip.cpp486
1 files changed, 486 insertions, 0 deletions
diff --git a/layout/painting/DisplayItemClip.cpp b/layout/painting/DisplayItemClip.cpp
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+++ b/layout/painting/DisplayItemClip.cpp
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+/* -*- 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 "DisplayItemClip.h"
+
+#include "gfxContext.h"
+#include "gfxUtils.h"
+#include "mozilla/gfx/2D.h"
+#include "mozilla/gfx/PathHelpers.h"
+#include "mozilla/layers/StackingContextHelper.h"
+#include "mozilla/StaticPtr.h"
+#include "mozilla/webrender/WebRenderTypes.h"
+#include "nsPresContext.h"
+#include "nsCSSRendering.h"
+#include "nsLayoutUtils.h"
+#include "nsRegion.h"
+
+using namespace mozilla::gfx;
+
+namespace mozilla {
+
+void DisplayItemClip::SetTo(const nsRect& aRect) { SetTo(aRect, nullptr); }
+
+void DisplayItemClip::SetTo(const nsRect& aRect, const nscoord* aRadii) {
+ mHaveClipRect = true;
+ mClipRect = aRect;
+ if (aRadii) {
+ mRoundedClipRects.SetLength(1);
+ mRoundedClipRects[0].mRect = aRect;
+ memcpy(mRoundedClipRects[0].mRadii, aRadii, sizeof(nscoord) * 8);
+ } else {
+ mRoundedClipRects.Clear();
+ }
+}
+
+void DisplayItemClip::SetTo(const nsRect& aRect, const nsRect& aRoundedRect,
+ const nscoord* aRadii) {
+ mHaveClipRect = true;
+ mClipRect = aRect;
+ mRoundedClipRects.SetLength(1);
+ mRoundedClipRects[0].mRect = aRoundedRect;
+ memcpy(mRoundedClipRects[0].mRadii, aRadii, sizeof(nscoord) * 8);
+}
+
+bool DisplayItemClip::MayIntersect(const nsRect& aRect) const {
+ if (!mHaveClipRect) {
+ return !aRect.IsEmpty();
+ }
+ nsRect r = aRect.Intersect(mClipRect);
+ if (r.IsEmpty()) {
+ return false;
+ }
+ for (uint32_t i = 0; i < mRoundedClipRects.Length(); ++i) {
+ const RoundedRect& rr = mRoundedClipRects[i];
+ if (!nsLayoutUtils::RoundedRectIntersectsRect(rr.mRect, rr.mRadii, r)) {
+ return false;
+ }
+ }
+ return true;
+}
+
+void DisplayItemClip::IntersectWith(const DisplayItemClip& aOther) {
+ if (!aOther.mHaveClipRect) {
+ return;
+ }
+ if (!mHaveClipRect) {
+ *this = aOther;
+ return;
+ }
+ if (!mClipRect.IntersectRect(mClipRect, aOther.mClipRect)) {
+ mRoundedClipRects.Clear();
+ return;
+ }
+ mRoundedClipRects.AppendElements(aOther.mRoundedClipRects);
+}
+
+void DisplayItemClip::ApplyTo(gfxContext* aContext, int32_t A2D) const {
+ ApplyRectTo(aContext, A2D);
+ ApplyRoundedRectClipsTo(aContext, A2D, 0, mRoundedClipRects.Length());
+}
+
+void DisplayItemClip::ApplyRectTo(gfxContext* aContext, int32_t A2D) const {
+ aContext->NewPath();
+ gfxRect clip = nsLayoutUtils::RectToGfxRect(mClipRect, A2D);
+ aContext->SnappedRectangle(clip);
+ aContext->Clip();
+}
+
+void DisplayItemClip::ApplyRoundedRectClipsTo(gfxContext* aContext, int32_t A2D,
+ uint32_t aBegin,
+ uint32_t aEnd) const {
+ DrawTarget& aDrawTarget = *aContext->GetDrawTarget();
+
+ aEnd = std::min<uint32_t>(aEnd, mRoundedClipRects.Length());
+
+ for (uint32_t i = aBegin; i < aEnd; ++i) {
+ RefPtr<Path> roundedRect =
+ MakeRoundedRectPath(aDrawTarget, A2D, mRoundedClipRects[i]);
+ aContext->Clip(roundedRect);
+ }
+}
+
+void DisplayItemClip::FillIntersectionOfRoundedRectClips(
+ gfxContext* aContext, const DeviceColor& aColor,
+ int32_t aAppUnitsPerDevPixel) const {
+ DrawTarget& aDrawTarget = *aContext->GetDrawTarget();
+
+ uint32_t end = mRoundedClipRects.Length();
+ if (!end) {
+ return;
+ }
+
+ // Push clips for any rects that come BEFORE the rect at |aEnd - 1|, if any:
+ ApplyRoundedRectClipsTo(aContext, aAppUnitsPerDevPixel, 0, end - 1);
+
+ // Now fill the rect at |aEnd - 1|:
+ RefPtr<Path> roundedRect = MakeRoundedRectPath(
+ aDrawTarget, aAppUnitsPerDevPixel, mRoundedClipRects[end - 1]);
+ aDrawTarget.Fill(roundedRect, ColorPattern(aColor));
+
+ // Finally, pop any clips that we may have pushed:
+ for (uint32_t i = 0; i < end - 1; ++i) {
+ aContext->PopClip();
+ }
+}
+
+already_AddRefed<Path> DisplayItemClip::MakeRoundedRectPath(
+ DrawTarget& aDrawTarget, int32_t A2D, const RoundedRect& aRoundRect) const {
+ RectCornerRadii pixelRadii;
+ nsCSSRendering::ComputePixelRadii(aRoundRect.mRadii, A2D, &pixelRadii);
+
+ Rect rect = NSRectToSnappedRect(aRoundRect.mRect, A2D, aDrawTarget);
+
+ return MakePathForRoundedRect(aDrawTarget, rect, pixelRadii);
+}
+
+nsRect DisplayItemClip::ApproximateIntersectInward(const nsRect& aRect) const {
+ nsRect r = aRect;
+ if (mHaveClipRect) {
+ r.IntersectRect(r, mClipRect);
+ }
+ for (uint32_t i = 0, iEnd = mRoundedClipRects.Length(); i < iEnd; ++i) {
+ const RoundedRect& rr = mRoundedClipRects[i];
+ nsRegion rgn =
+ nsLayoutUtils::RoundedRectIntersectRect(rr.mRect, rr.mRadii, r);
+ r = rgn.GetLargestRectangle();
+ }
+ return r;
+}
+
+// Test if (aXPoint, aYPoint) is in the ellipse with center (aXCenter, aYCenter)
+// and radii aXRadius, aYRadius.
+static bool IsInsideEllipse(nscoord aXRadius, nscoord aXCenter, nscoord aXPoint,
+ nscoord aYRadius, nscoord aYCenter,
+ nscoord aYPoint) {
+ float scaledX = float(aXPoint - aXCenter) / float(aXRadius);
+ float scaledY = float(aYPoint - aYCenter) / float(aYRadius);
+ return scaledX * scaledX + scaledY * scaledY < 1.0f;
+}
+
+bool DisplayItemClip::IsRectClippedByRoundedCorner(const nsRect& aRect) const {
+ if (mRoundedClipRects.IsEmpty()) return false;
+
+ nsRect rect;
+ rect.IntersectRect(aRect, NonRoundedIntersection());
+ for (uint32_t i = 0, iEnd = mRoundedClipRects.Length(); i < iEnd; ++i) {
+ const RoundedRect& rr = mRoundedClipRects[i];
+ // top left
+ if (rect.x < rr.mRect.x + rr.mRadii[eCornerTopLeftX] &&
+ rect.y < rr.mRect.y + rr.mRadii[eCornerTopLeftY]) {
+ if (!IsInsideEllipse(rr.mRadii[eCornerTopLeftX],
+ rr.mRect.x + rr.mRadii[eCornerTopLeftX], rect.x,
+ rr.mRadii[eCornerTopLeftY],
+ rr.mRect.y + rr.mRadii[eCornerTopLeftY], rect.y)) {
+ return true;
+ }
+ }
+ // top right
+ if (rect.XMost() > rr.mRect.XMost() - rr.mRadii[eCornerTopRightX] &&
+ rect.y < rr.mRect.y + rr.mRadii[eCornerTopRightY]) {
+ if (!IsInsideEllipse(rr.mRadii[eCornerTopRightX],
+ rr.mRect.XMost() - rr.mRadii[eCornerTopRightX],
+ rect.XMost(), rr.mRadii[eCornerTopRightY],
+ rr.mRect.y + rr.mRadii[eCornerTopRightY], rect.y)) {
+ return true;
+ }
+ }
+ // bottom left
+ if (rect.x < rr.mRect.x + rr.mRadii[eCornerBottomLeftX] &&
+ rect.YMost() > rr.mRect.YMost() - rr.mRadii[eCornerBottomLeftY]) {
+ if (!IsInsideEllipse(rr.mRadii[eCornerBottomLeftX],
+ rr.mRect.x + rr.mRadii[eCornerBottomLeftX], rect.x,
+ rr.mRadii[eCornerBottomLeftY],
+ rr.mRect.YMost() - rr.mRadii[eCornerBottomLeftY],
+ rect.YMost())) {
+ return true;
+ }
+ }
+ // bottom right
+ if (rect.XMost() > rr.mRect.XMost() - rr.mRadii[eCornerBottomRightX] &&
+ rect.YMost() > rr.mRect.YMost() - rr.mRadii[eCornerBottomRightY]) {
+ if (!IsInsideEllipse(rr.mRadii[eCornerBottomRightX],
+ rr.mRect.XMost() - rr.mRadii[eCornerBottomRightX],
+ rect.XMost(), rr.mRadii[eCornerBottomRightY],
+ rr.mRect.YMost() - rr.mRadii[eCornerBottomRightY],
+ rect.YMost())) {
+ return true;
+ }
+ }
+ }
+ return false;
+}
+
+nsRect DisplayItemClip::NonRoundedIntersection() const {
+ NS_ASSERTION(mHaveClipRect, "Must have a clip rect!");
+ nsRect result = mClipRect;
+ for (uint32_t i = 0, iEnd = mRoundedClipRects.Length(); i < iEnd; ++i) {
+ result.IntersectRect(result, mRoundedClipRects[i].mRect);
+ }
+ return result;
+}
+
+bool DisplayItemClip::IsRectAffectedByClip(const nsRect& aRect) const {
+ if (mHaveClipRect && !mClipRect.Contains(aRect)) {
+ return true;
+ }
+ for (uint32_t i = 0, iEnd = mRoundedClipRects.Length(); i < iEnd; ++i) {
+ const RoundedRect& rr = mRoundedClipRects[i];
+ nsRegion rgn =
+ nsLayoutUtils::RoundedRectIntersectRect(rr.mRect, rr.mRadii, aRect);
+ if (!rgn.Contains(aRect)) {
+ return true;
+ }
+ }
+ return false;
+}
+
+bool DisplayItemClip::IsRectAffectedByClip(const nsIntRect& aRect,
+ float aXScale, float aYScale,
+ int32_t A2D) const {
+ if (mHaveClipRect) {
+ nsIntRect pixelClipRect =
+ mClipRect.ScaleToNearestPixels(aXScale, aYScale, A2D);
+ if (!pixelClipRect.Contains(aRect)) {
+ return true;
+ }
+ }
+
+ // Rounded rect clipping only snaps to user-space pixels, not device space.
+ nsIntRect unscaled = aRect;
+ unscaled.Scale(1 / aXScale, 1 / aYScale);
+
+ for (uint32_t i = 0, iEnd = mRoundedClipRects.Length(); i < iEnd; ++i) {
+ const RoundedRect& rr = mRoundedClipRects[i];
+
+ nsIntRect pixelRect = rr.mRect.ToNearestPixels(A2D);
+
+ RectCornerRadii pixelRadii;
+ nsCSSRendering::ComputePixelRadii(rr.mRadii, A2D, &pixelRadii);
+
+ nsIntRegion rgn = nsLayoutUtils::RoundedRectIntersectIntRect(
+ pixelRect, pixelRadii, unscaled);
+ if (!rgn.Contains(unscaled)) {
+ return true;
+ }
+ }
+ return false;
+}
+
+nsRect DisplayItemClip::ApplyNonRoundedIntersection(const nsRect& aRect) const {
+ if (!mHaveClipRect) {
+ return aRect;
+ }
+
+ nsRect result = aRect.Intersect(mClipRect);
+ for (uint32_t i = 0, iEnd = mRoundedClipRects.Length(); i < iEnd; ++i) {
+ result = result.Intersect(mRoundedClipRects[i].mRect);
+ }
+ return result;
+}
+
+void DisplayItemClip::RemoveRoundedCorners() {
+ if (mRoundedClipRects.IsEmpty()) return;
+
+ mClipRect = NonRoundedIntersection();
+ mRoundedClipRects.Clear();
+}
+
+// Computes the difference between aR1 and aR2, limited to aBounds.
+static void AccumulateRectDifference(const nsRect& aR1, const nsRect& aR2,
+ const nsRect& aBounds, nsRegion* aOut) {
+ if (aR1.IsEqualInterior(aR2)) return;
+ nsRegion r;
+ r.Xor(aR1, aR2);
+ r.And(r, aBounds);
+ aOut->Or(*aOut, r);
+}
+
+static void AccumulateRoundedRectDifference(
+ const DisplayItemClip::RoundedRect& aR1,
+ const DisplayItemClip::RoundedRect& aR2, const nsRect& aBounds,
+ const nsRect& aOtherBounds, nsRegion* aOut) {
+ const nsRect& rect1 = aR1.mRect;
+ const nsRect& rect2 = aR2.mRect;
+
+ // If the two rectangles are totally disjoint, just add them both - otherwise
+ // we'd end up adding one big enclosing rect
+ if (!rect1.Intersects(rect2) ||
+ memcmp(aR1.mRadii, aR2.mRadii, sizeof(aR1.mRadii))) {
+ aOut->Or(*aOut, rect1.Intersect(aBounds));
+ aOut->Or(*aOut, rect2.Intersect(aOtherBounds));
+ return;
+ }
+
+ nscoord lowestBottom = std::max(rect1.YMost(), rect2.YMost());
+ nscoord highestTop = std::min(rect1.Y(), rect2.Y());
+ nscoord maxRight = std::max(rect1.XMost(), rect2.XMost());
+ nscoord minLeft = std::min(rect1.X(), rect2.X());
+
+ // At this point, we know that the radii haven't changed, and that the bounds
+ // are different in some way. To explain how this works, consider the case
+ // where the rounded rect has just been translated along the X direction.
+ // | ______________________ _ _ _ _ _ _ |
+ // | / / \ \ |
+ // | | | |
+ // | | aR1 | | aR2 | |
+ // | | | |
+ // | \ __________\___________ / _ _ _ _ _ / |
+ // | |
+ // The invalidation region will be as if we lopped off the left rounded part
+ // of aR2, and the right rounded part of aR1, and XOR'd them:
+ // | ______________________ _ _ _ _ _ _ |
+ // | -/-----------/- -\-----------\- |
+ // | |-------------- --|------------ |
+ // | |-----aR1---|-- --|-----aR2---| |
+ // | |-------------- --|------------ |
+ // | -\ __________\-__________-/ _ _ _ _ _ /- |
+ // | |
+ // The logic below just implements this idea, but generalized to both the
+ // X and Y dimensions. The "(...)Adjusted(...)" values represent the lopped
+ // off sides.
+ nscoord highestAdjustedBottom = std::min(
+ rect1.YMost() - aR1.mRadii[eCornerBottomLeftY],
+ std::min(rect1.YMost() - aR1.mRadii[eCornerBottomRightY],
+ std::min(rect2.YMost() - aR2.mRadii[eCornerBottomLeftY],
+ rect2.YMost() - aR2.mRadii[eCornerBottomRightY])));
+ nscoord lowestAdjustedTop =
+ std::max(rect1.Y() + aR1.mRadii[eCornerTopLeftY],
+ std::max(rect1.Y() + aR1.mRadii[eCornerTopRightY],
+ std::max(rect2.Y() + aR2.mRadii[eCornerTopLeftY],
+ rect2.Y() + aR2.mRadii[eCornerTopRightY])));
+
+ nscoord minAdjustedRight = std::min(
+ rect1.XMost() - aR1.mRadii[eCornerTopRightX],
+ std::min(rect1.XMost() - aR1.mRadii[eCornerBottomRightX],
+ std::min(rect2.XMost() - aR2.mRadii[eCornerTopRightX],
+ rect2.XMost() - aR2.mRadii[eCornerBottomRightX])));
+ nscoord maxAdjustedLeft =
+ std::max(rect1.X() + aR1.mRadii[eCornerTopLeftX],
+ std::max(rect1.X() + aR1.mRadii[eCornerBottomLeftX],
+ std::max(rect2.X() + aR2.mRadii[eCornerTopLeftX],
+ rect2.X() + aR2.mRadii[eCornerBottomLeftX])));
+
+ // We only want to add an invalidation rect if the bounds have changed. If we
+ // always added all of the 4 rects below, we would always be invalidating a
+ // border around the rects, even in cases where we just translated along the X
+ // or Y axis.
+ nsRegion r;
+ // First, or with the Y delta rects, wide along the X axis
+ if (rect1.Y() != rect2.Y()) {
+ r.Or(r, nsRect(minLeft, highestTop, maxRight - minLeft,
+ lowestAdjustedTop - highestTop));
+ }
+ if (rect1.YMost() != rect2.YMost()) {
+ r.Or(r, nsRect(minLeft, highestAdjustedBottom, maxRight - minLeft,
+ lowestBottom - highestAdjustedBottom));
+ }
+ // Then, or with the X delta rects, wide along the Y axis
+ if (rect1.X() != rect2.X()) {
+ r.Or(r, nsRect(minLeft, highestTop, maxAdjustedLeft - minLeft,
+ lowestBottom - highestTop));
+ }
+ if (rect1.XMost() != rect2.XMost()) {
+ r.Or(r, nsRect(minAdjustedRight, highestTop, maxRight - minAdjustedRight,
+ lowestBottom - highestTop));
+ }
+
+ r.And(r, aBounds.Union(aOtherBounds));
+ aOut->Or(*aOut, r);
+}
+
+void DisplayItemClip::AddOffsetAndComputeDifference(
+ const nsPoint& aOffset, const nsRect& aBounds,
+ const DisplayItemClip& aOther, const nsRect& aOtherBounds,
+ nsRegion* aDifference) {
+ if (mHaveClipRect != aOther.mHaveClipRect ||
+ mRoundedClipRects.Length() != aOther.mRoundedClipRects.Length()) {
+ aDifference->Or(*aDifference, aBounds);
+ aDifference->Or(*aDifference, aOtherBounds);
+ return;
+ }
+ if (mHaveClipRect) {
+ AccumulateRectDifference(mClipRect + aOffset, aOther.mClipRect,
+ aBounds.Union(aOtherBounds), aDifference);
+ }
+ for (uint32_t i = 0; i < mRoundedClipRects.Length(); ++i) {
+ if (mRoundedClipRects[i] + aOffset != aOther.mRoundedClipRects[i]) {
+ AccumulateRoundedRectDifference(mRoundedClipRects[i] + aOffset,
+ aOther.mRoundedClipRects[i], aBounds,
+ aOtherBounds, aDifference);
+ }
+ }
+}
+
+void DisplayItemClip::AppendRoundedRects(nsTArray<RoundedRect>* aArray) const {
+ aArray->AppendElements(mRoundedClipRects.Elements(),
+ mRoundedClipRects.Length());
+}
+
+bool DisplayItemClip::ComputeRegionInClips(const DisplayItemClip* aOldClip,
+ const nsPoint& aShift,
+ nsRegion* aCombined) const {
+ if (!mHaveClipRect || (aOldClip && !aOldClip->mHaveClipRect)) {
+ return false;
+ }
+
+ if (aOldClip) {
+ *aCombined = aOldClip->NonRoundedIntersection();
+ aCombined->MoveBy(aShift);
+ aCombined->Or(*aCombined, NonRoundedIntersection());
+ } else {
+ *aCombined = NonRoundedIntersection();
+ }
+ return true;
+}
+
+void DisplayItemClip::MoveBy(const nsPoint& aPoint) {
+ if (!mHaveClipRect) {
+ return;
+ }
+ mClipRect += aPoint;
+ for (uint32_t i = 0; i < mRoundedClipRects.Length(); ++i) {
+ mRoundedClipRects[i].mRect += aPoint;
+ }
+}
+
+static StaticAutoPtr<DisplayItemClip> gNoClip;
+
+const DisplayItemClip& DisplayItemClip::NoClip() {
+ if (!gNoClip) {
+ gNoClip = new DisplayItemClip();
+ }
+ return *gNoClip;
+}
+
+void DisplayItemClip::Shutdown() { gNoClip = nullptr; }
+
+nsCString DisplayItemClip::ToString() const {
+ nsAutoCString str;
+ if (mHaveClipRect) {
+ str.AppendPrintf("%d,%d,%d,%d", mClipRect.x, mClipRect.y, mClipRect.width,
+ mClipRect.height);
+ for (uint32_t i = 0; i < mRoundedClipRects.Length(); ++i) {
+ const RoundedRect& r = mRoundedClipRects[i];
+ str.AppendPrintf(" [%d,%d,%d,%d corners %d,%d,%d,%d,%d,%d,%d,%d]",
+ r.mRect.x, r.mRect.y, r.mRect.width, r.mRect.height,
+ r.mRadii[0], r.mRadii[1], r.mRadii[2], r.mRadii[3],
+ r.mRadii[4], r.mRadii[5], r.mRadii[6], r.mRadii[7]);
+ }
+ }
+ return std::move(str);
+}
+
+void DisplayItemClip::ToComplexClipRegions(
+ int32_t aAppUnitsPerDevPixel,
+ nsTArray<wr::ComplexClipRegion>& aOutArray) const {
+ for (const auto& clipRect : mRoundedClipRects) {
+ aOutArray.AppendElement(wr::ToComplexClipRegion(
+ clipRect.mRect, clipRect.mRadii, aAppUnitsPerDevPixel));
+ }
+}
+
+} // namespace mozilla