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-rw-r--r--layout/base/ShapeUtils.cpp150
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diff --git a/layout/base/ShapeUtils.cpp b/layout/base/ShapeUtils.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 "mozilla/ShapeUtils.h"
+
+#include <cstdlib>
+
+#include "nsCSSRendering.h"
+#include "nsMargin.h"
+#include "nsStyleStruct.h"
+#include "mozilla/SVGContentUtils.h"
+
+namespace mozilla {
+
+nscoord ShapeUtils::ComputeShapeRadius(const StyleShapeRadius& aType,
+ const nscoord aCenter,
+ const nscoord aPosMin,
+ const nscoord aPosMax) {
+ MOZ_ASSERT(aType.IsFarthestSide() || aType.IsClosestSide());
+ nscoord dist1 = std::abs(aPosMin - aCenter);
+ nscoord dist2 = std::abs(aPosMax - aCenter);
+ nscoord length = 0;
+ if (aType.IsFarthestSide()) {
+ length = dist1 > dist2 ? dist1 : dist2;
+ } else {
+ length = dist1 > dist2 ? dist2 : dist1;
+ }
+ return length;
+}
+
+nsPoint ShapeUtils::ComputeCircleOrEllipseCenter(
+ const StyleBasicShape& aBasicShape, const nsRect& aRefBox) {
+ MOZ_ASSERT(aBasicShape.IsCircle() || aBasicShape.IsEllipse(),
+ "The basic shape must be circle() or ellipse!");
+
+ const auto& position = aBasicShape.IsCircle()
+ ? aBasicShape.AsCircle().position
+ : aBasicShape.AsEllipse().position;
+
+ nsPoint topLeft, anchor;
+ nsSize size(aRefBox.Size());
+ nsImageRenderer::ComputeObjectAnchorPoint(position, size, size, &topLeft,
+ &anchor);
+ return anchor + aRefBox.TopLeft();
+}
+
+nscoord ShapeUtils::ComputeCircleRadius(const StyleBasicShape& aBasicShape,
+ const nsPoint& aCenter,
+ const nsRect& aRefBox) {
+ MOZ_ASSERT(aBasicShape.IsCircle(), "The basic shape must be circle()!");
+ const auto& radius = aBasicShape.AsCircle().radius;
+ if (radius.IsLength()) {
+ return radius.AsLength().Resolve([&] {
+ // We resolve percent <shape-radius> value for circle() as defined here:
+ // https://drafts.csswg.org/css-shapes/#funcdef-circle
+ double referenceLength = SVGContentUtils::ComputeNormalizedHypotenuse(
+ aRefBox.width, aRefBox.height);
+ return NSToCoordRound(referenceLength);
+ });
+ }
+
+ nscoord horizontal =
+ ComputeShapeRadius(radius, aCenter.x, aRefBox.x, aRefBox.XMost());
+ nscoord vertical =
+ ComputeShapeRadius(radius, aCenter.y, aRefBox.y, aRefBox.YMost());
+ return radius.IsFarthestSide() ? std::max(horizontal, vertical)
+ : std::min(horizontal, vertical);
+}
+
+nsSize ShapeUtils::ComputeEllipseRadii(const StyleBasicShape& aBasicShape,
+ const nsPoint& aCenter,
+ const nsRect& aRefBox) {
+ MOZ_ASSERT(aBasicShape.IsEllipse(), "The basic shape must be ellipse()!");
+ const auto& ellipse = aBasicShape.AsEllipse();
+ nsSize radii;
+ if (ellipse.semiaxis_x.IsLength()) {
+ radii.width = ellipse.semiaxis_x.AsLength().Resolve(aRefBox.width);
+ } else {
+ radii.width = ComputeShapeRadius(ellipse.semiaxis_x, aCenter.x, aRefBox.x,
+ aRefBox.XMost());
+ }
+
+ if (ellipse.semiaxis_y.IsLength()) {
+ radii.height = ellipse.semiaxis_y.AsLength().Resolve(aRefBox.height);
+ } else {
+ radii.height = ComputeShapeRadius(ellipse.semiaxis_y, aCenter.y, aRefBox.y,
+ aRefBox.YMost());
+ }
+
+ return radii;
+}
+
+/* static */
+nsRect ShapeUtils::ComputeInsetRect(const StyleBasicShape& aBasicShape,
+ const nsRect& aRefBox) {
+ MOZ_ASSERT(aBasicShape.IsInset(), "The basic shape must be inset()!");
+ const auto& rect = aBasicShape.AsInset().rect;
+ nsMargin inset(
+ rect._0.Resolve(aRefBox.Height()), rect._1.Resolve(aRefBox.Width()),
+ rect._2.Resolve(aRefBox.Height()), rect._3.Resolve(aRefBox.Width()));
+
+ nscoord x = aRefBox.X() + inset.left;
+ nscoord width = aRefBox.Width() - inset.LeftRight();
+ nscoord y = aRefBox.Y() + inset.top;
+ nscoord height = aRefBox.Height() - inset.TopBottom();
+
+ // Invert left and right, if necessary.
+ if (width < 0) {
+ width *= -1;
+ x -= width;
+ }
+
+ // Invert top and bottom, if necessary.
+ if (height < 0) {
+ height *= -1;
+ y -= height;
+ }
+
+ return nsRect(x, y, width, height);
+}
+
+/* static */
+bool ShapeUtils::ComputeInsetRadii(const StyleBasicShape& aBasicShape,
+ const nsRect& aRefBox,
+ const nsRect& aInsetRect,
+ nscoord aRadii[8]) {
+ const auto& radius = aBasicShape.AsInset().round;
+ return nsIFrame::ComputeBorderRadii(radius, aRefBox.Size(), aInsetRect.Size(),
+ Sides(), aRadii);
+}
+
+/* static */
+nsTArray<nsPoint> ShapeUtils::ComputePolygonVertices(
+ const StyleBasicShape& aBasicShape, const nsRect& aRefBox) {
+ MOZ_ASSERT(aBasicShape.IsPolygon(), "The basic shape must be polygon()!");
+
+ auto coords = aBasicShape.AsPolygon().coordinates.AsSpan();
+ nsTArray<nsPoint> vertices(coords.Length());
+ for (const StylePolygonCoord<LengthPercentage>& point : coords) {
+ vertices.AppendElement(nsPoint(point._0.Resolve(aRefBox.width),
+ point._1.Resolve(aRefBox.height)) +
+ aRefBox.TopLeft());
+ }
+ return vertices;
+}
+
+} // namespace mozilla