Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 399 insertions, 0 deletions

diff --git a/gfx/2d/PathHelpers.h b/gfx/2d/PathHelpers.h
new file mode 100644
index 0000000000..5fd6d45934
--- /dev/null
+++ b/gfx/2d/PathHelpers.h
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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/. */
+
+#ifndef MOZILLA_GFX_PATHHELPERS_H_
+#define MOZILLA_GFX_PATHHELPERS_H_
+
+#include "2D.h"
+#include "UserData.h"
+
+#include <cmath>
+
+namespace mozilla {
+namespace gfx {
+
+struct PathOp {
+  ~PathOp() = default;
+
+  enum OpType {
+    OP_MOVETO = 0,
+    OP_LINETO,
+    OP_BEZIERTO,
+    OP_QUADRATICBEZIERTO,
+    OP_ARC,
+    OP_CLOSE
+  };
+
+  OpType mType;
+  Point mP1;
+#if (!defined(__GNUC__) || __GNUC__ >= 7) && defined(__clang__)
+  PathOp() {}
+
+  union {
+    struct {
+      Point mP2;
+      Point mP3;
+    };
+    struct {
+      float mRadius;
+      float mStartAngle;
+      float mEndAngle;
+      bool mAntiClockwise;
+    };
+  };
+#else
+  PathOp() = default;
+
+  Point mP2;
+  Point mP3;
+  float mRadius;
+  float mStartAngle;
+  float mEndAngle;
+  bool mAntiClockwise;
+#endif
+};
+
+const int32_t sPointCount[] = {1, 1, 3, 2, 0, 0};
+
+// Kappa constant for 90-degree angle
+const Float kKappaFactor = 0.55191497064665766025f;
+
+// Calculate kappa constant for partial curve. The sign of angle in the
+// tangent will actually ensure this is negative for a counter clockwise
+// sweep, so changing signs later isn't needed.
+inline Float ComputeKappaFactor(Float aAngle) {
+  return (4.0f / 3.0f) * tanf(aAngle / 4.0f);
+}
+
+/**
+ * Draws a partial arc <= 90 degrees given exact start and end points.
+ * Assumes that it is continuing from an already specified start point.
+ */
+template <typename T>
+inline void PartialArcToBezier(T* aSink, const Point& aStartOffset,
+                               const Point& aEndOffset,
+                               const Matrix& aTransform,
+                               Float aKappaFactor = kKappaFactor) {
+  Point cp1 =
+      aStartOffset + Point(-aStartOffset.y, aStartOffset.x) * aKappaFactor;
+
+  Point cp2 = aEndOffset + Point(aEndOffset.y, -aEndOffset.x) * aKappaFactor;
+
+  aSink->BezierTo(aTransform.TransformPoint(cp1),
+                  aTransform.TransformPoint(cp2),
+                  aTransform.TransformPoint(aEndOffset));
+}
+
+/**
+ * Draws an acute arc (<= 90 degrees) given exact start and end points.
+ * Specialized version avoiding kappa calculation.
+ */
+template <typename T>
+inline void AcuteArcToBezier(T* aSink, const Point& aOrigin,
+                             const Size& aRadius, const Point& aStartPoint,
+                             const Point& aEndPoint,
+                             Float aKappaFactor = kKappaFactor) {
+  aSink->LineTo(aStartPoint);
+  if (!aRadius.IsEmpty()) {
+    Float kappaX = aKappaFactor * aRadius.width / aRadius.height;
+    Float kappaY = aKappaFactor * aRadius.height / aRadius.width;
+    Point startOffset = aStartPoint - aOrigin;
+    Point endOffset = aEndPoint - aOrigin;
+    aSink->BezierTo(
+        aStartPoint + Point(-startOffset.y * kappaX, startOffset.x * kappaY),
+        aEndPoint + Point(endOffset.y * kappaX, -endOffset.x * kappaY),
+        aEndPoint);
+  } else if (aEndPoint != aStartPoint) {
+    aSink->LineTo(aEndPoint);
+  }
+}
+
+/**
+ * Draws an acute arc (<= 90 degrees) given exact start and end points.
+ */
+template <typename T>
+inline void AcuteArcToBezier(T* aSink, const Point& aOrigin,
+                             const Size& aRadius, const Point& aStartPoint,
+                             const Point& aEndPoint, Float aStartAngle,
+                             Float aEndAngle) {
+  AcuteArcToBezier(aSink, aOrigin, aRadius, aStartPoint, aEndPoint,
+                   ComputeKappaFactor(aEndAngle - aStartAngle));
+}
+
+template <typename T>
+void ArcToBezier(T* aSink, const Point& aOrigin, const Size& aRadius,
+                 float aStartAngle, float aEndAngle, bool aAntiClockwise,
+                 float aRotation = 0.0f, const Matrix& aTransform = Matrix()) {
+  Float sweepDirection = aAntiClockwise ? -1.0f : 1.0f;
+
+  // Calculate the total arc we're going to sweep.
+  Float arcSweepLeft = (aEndAngle - aStartAngle) * sweepDirection;
+
+  // Clockwise we always sweep from the smaller to the larger angle, ccw
+  // it's vice versa.
+  if (arcSweepLeft < 0) {
+    // Rerverse sweep is modulo'd into range rather than clamped.
+    arcSweepLeft = Float(2.0f * M_PI) + fmodf(arcSweepLeft, Float(2.0f * M_PI));
+    // Recalculate the start angle to land closer to end angle.
+    aStartAngle = aEndAngle - arcSweepLeft * sweepDirection;
+  } else if (arcSweepLeft > Float(2.0f * M_PI)) {
+    // Sweeping more than 2 * pi is a full circle.
+    arcSweepLeft = Float(2.0f * M_PI);
+  }
+
+  Float currentStartAngle = aStartAngle;
+  Point currentStartOffset(cosf(aStartAngle), sinf(aStartAngle));
+  Matrix transform = Matrix::Scaling(aRadius.width, aRadius.height);
+  if (aRotation != 0.0f) {
+    transform *= Matrix::Rotation(aRotation);
+  }
+  transform.PostTranslate(aOrigin);
+  transform *= aTransform;
+  aSink->LineTo(transform.TransformPoint(currentStartOffset));
+
+  while (arcSweepLeft > 0) {
+    Float currentEndAngle =
+        currentStartAngle +
+        std::min(arcSweepLeft, Float(M_PI / 2.0f)) * sweepDirection;
+    Point currentEndOffset(cosf(currentEndAngle), sinf(currentEndAngle));
+
+    PartialArcToBezier(aSink, currentStartOffset, currentEndOffset, transform,
+                       ComputeKappaFactor(currentEndAngle - currentStartAngle));
+
+    // We guarantee here the current point is the start point of the next
+    // curve segment.
+    arcSweepLeft -= Float(M_PI / 2.0f);
+    currentStartAngle = currentEndAngle;
+    currentStartOffset = currentEndOffset;
+  }
+}
+
+/* This is basically the ArcToBezier with the parameters for drawing a circle
+ * inlined which vastly simplifies it and avoids a bunch of transcedental
+ * function calls which should make it faster. */
+template <typename T>
+void EllipseToBezier(T* aSink, const Point& aOrigin, const Size& aRadius) {
+  Matrix transform(aRadius.width, 0, 0, aRadius.height, aOrigin.x, aOrigin.y);
+  Point currentStartOffset(1, 0);
+
+  aSink->LineTo(transform.TransformPoint(currentStartOffset));
+
+  for (int i = 0; i < 4; i++) {
+    // cos(x+pi/2) == -sin(x)
+    // sin(x+pi/2) == cos(x)
+    Point currentEndOffset(-currentStartOffset.y, currentStartOffset.x);
+
+    PartialArcToBezier(aSink, currentStartOffset, currentEndOffset, transform);
+
+    // We guarantee here the current point is the start point of the next
+    // curve segment.
+    currentStartOffset = currentEndOffset;
+  }
+}
+
+/**
+ * Appends a path represending a rectangle to the path being built by
+ * aPathBuilder.
+ *
+ * aRect           The rectangle to append.
+ * aDrawClockwise  If set to true, the path will start at the left of the top
+ *                 left edge and draw clockwise. If set to false the path will
+ *                 start at the right of the top left edge and draw counter-
+ *                 clockwise.
+ */
+GFX2D_API void AppendRectToPath(PathBuilder* aPathBuilder, const Rect& aRect,
+                                bool aDrawClockwise = true);
+
+inline already_AddRefed<Path> MakePathForRect(const DrawTarget& aDrawTarget,
+                                              const Rect& aRect,
+                                              bool aDrawClockwise = true) {
+  RefPtr<PathBuilder> builder = aDrawTarget.CreatePathBuilder();
+  AppendRectToPath(builder, aRect, aDrawClockwise);
+  return builder->Finish();
+}
+
+/**
+ * Appends a path represending a rounded rectangle to the path being built by
+ * aPathBuilder.
+ *
+ * aRect           The rectangle to append.
+ * aCornerRadii    Contains the radii of the top-left, top-right, bottom-right
+ *                 and bottom-left corners, in that order.
+ * aDrawClockwise  If set to true, the path will start at the left of the top
+ *                 left edge and draw clockwise. If set to false the path will
+ *                 start at the right of the top left edge and draw counter-
+ *                 clockwise.
+ */
+GFX2D_API void AppendRoundedRectToPath(
+    PathBuilder* aPathBuilder, const Rect& aRect, const RectCornerRadii& aRadii,
+    bool aDrawClockwise = true, const Maybe<Matrix>& aTransform = Nothing());
+
+inline already_AddRefed<Path> MakePathForRoundedRect(
+    const DrawTarget& aDrawTarget, const Rect& aRect,
+    const RectCornerRadii& aRadii, bool aDrawClockwise = true) {
+  RefPtr<PathBuilder> builder = aDrawTarget.CreatePathBuilder();
+  AppendRoundedRectToPath(builder, aRect, aRadii, aDrawClockwise);
+  return builder->Finish();
+}
+
+/**
+ * Appends a path represending an ellipse to the path being built by
+ * aPathBuilder.
+ *
+ * The ellipse extends aDimensions.width / 2.0 in the horizontal direction
+ * from aCenter, and aDimensions.height / 2.0 in the vertical direction.
+ */
+GFX2D_API void AppendEllipseToPath(PathBuilder* aPathBuilder,
+                                   const Point& aCenter,
+                                   const Size& aDimensions);
+
+inline already_AddRefed<Path> MakePathForEllipse(const DrawTarget& aDrawTarget,
+                                                 const Point& aCenter,
+                                                 const Size& aDimensions) {
+  RefPtr<PathBuilder> builder = aDrawTarget.CreatePathBuilder();
+  AppendEllipseToPath(builder, aCenter, aDimensions);
+  return builder->Finish();
+}
+
+inline already_AddRefed<Path> MakePathForCircle(const DrawTarget& aDrawTarget,
+                                                const Point& aCenter,
+                                                float aRadius) {
+  RefPtr<PathBuilder> builder = aDrawTarget.CreatePathBuilder();
+  builder->Arc(aCenter, aRadius, 0.0f, Float(2.0 * M_PI));
+  builder->Close();
+  return builder->Finish();
+}
+
+/**
+ * If aDrawTarget's transform only contains a translation, and if this line is
+ * a horizontal or vertical line, this function will snap the line's vertices
+ * to align with the device pixel grid so that stroking the line with a one
+ * pixel wide stroke will result in a crisp line that is not antialiased over
+ * two pixels across its width.
+ *
+ * @return Returns true if this function snaps aRect's vertices, else returns
+ *   false.
+ */
+GFX2D_API bool SnapLineToDevicePixelsForStroking(Point& aP1, Point& aP2,
+                                                 const DrawTarget& aDrawTarget,
+                                                 Float aLineWidth);
+
+/**
+ * This function paints each edge of aRect separately, snapping the edges using
+ * SnapLineToDevicePixelsForStroking. Stroking the edges as separate paths
+ * helps ensure not only that the stroke spans a single row of device pixels if
+ * possible, but also that the ends of stroke dashes start and end on device
+ * pixels too.
+ */
+GFX2D_API void StrokeSnappedEdgesOfRect(const Rect& aRect,
+                                        DrawTarget& aDrawTarget,
+                                        const ColorPattern& aColor,
+                                        const StrokeOptions& aStrokeOptions);
+
+/**
+ * Return the margin, in device space, by which a stroke can extend beyond the
+ * rendered shape.
+ * @param  aStrokeOptions The stroke options that the stroke is drawn with.
+ * @param  aTransform     The user space to device space transform.
+ * @return                The stroke margin.
+ */
+GFX2D_API Margin MaxStrokeExtents(const StrokeOptions& aStrokeOptions,
+                                  const Matrix& aTransform);
+
+extern UserDataKey sDisablePixelSnapping;
+
+/**
+ * If aDrawTarget's transform only contains a translation or, if
+ * aAllowScaleOr90DegreeRotate is true, and/or a scale/90 degree rotation, this
+ * function will convert aRect to device space and snap it to device pixels.
+ * This function returns true if aRect is modified, otherwise it returns false.
+ *
+ * Note that the snapping is such that filling the rect using a DrawTarget
+ * which has the identity matrix as its transform will result in crisp edges.
+ * (That is, aRect will have integer values, aligning its edges between pixel
+ * boundaries.)  If on the other hand you stroking the rect with an odd valued
+ * stroke width then the edges of the stroke will be antialiased (assuming an
+ * AntialiasMode that does antialiasing).
+ *
+ * Empty snaps are those which result in a rectangle of 0 area.  If they are
+ * disallowed, an axis is left unsnapped if the rounding process results in a
+ * length of 0.
+ */
+inline bool UserToDevicePixelSnapped(Rect& aRect, const DrawTarget& aDrawTarget,
+                                     bool aAllowScaleOr90DegreeRotate = false,
+                                     bool aAllowEmptySnaps = true) {
+  if (aDrawTarget.GetUserData(&sDisablePixelSnapping)) {
+    return false;
+  }
+
+  Matrix mat = aDrawTarget.GetTransform();
+
+  const Float epsilon = 0.0000001f;
+#define WITHIN_E(a, b) (fabs((a) - (b)) < epsilon)
+  if (!aAllowScaleOr90DegreeRotate &&
+      (!WITHIN_E(mat._11, 1.f) || !WITHIN_E(mat._22, 1.f) ||
+       !WITHIN_E(mat._12, 0.f) || !WITHIN_E(mat._21, 0.f))) {
+    // We have non-translation, but only translation is allowed.
+    return false;
+  }
+#undef WITHIN_E
+
+  Point p1 = mat.TransformPoint(aRect.TopLeft());
+  Point p2 = mat.TransformPoint(aRect.TopRight());
+  Point p3 = mat.TransformPoint(aRect.BottomRight());
+
+  // Check that the rectangle is axis-aligned. For an axis-aligned rectangle,
+  // two opposite corners define the entire rectangle. So check if
+  // the axis-aligned rectangle with opposite corners p1 and p3
+  // define an axis-aligned rectangle whose other corners are p2 and p4.
+  // We actually only need to check one of p2 and p4, since an affine
+  // transform maps parallelograms to parallelograms.
+  if (p2 == Point(p1.x, p3.y) || p2 == Point(p3.x, p1.y)) {
+    Point p1r = p1;
+    Point p3r = p3;
+    p1r.Round();
+    p3r.Round();
+    if (aAllowEmptySnaps || p1r.x != p3r.x) {
+      p1.x = p1r.x;
+      p3.x = p3r.x;
+    }
+    if (aAllowEmptySnaps || p1r.y != p3r.y) {
+      p1.y = p1r.y;
+      p3.y = p3r.y;
+    }
+
+    aRect.MoveTo(Point(std::min(p1.x, p3.x), std::min(p1.y, p3.y)));
+    aRect.SizeTo(Size(std::max(p1.x, p3.x) - aRect.X(),
+                      std::max(p1.y, p3.y) - aRect.Y()));
+    return true;
+  }
+
+  return false;
+}
+
+/**
+ * This function has the same behavior as UserToDevicePixelSnapped except that
+ * aRect is not transformed to device space.
+ */
+inline bool MaybeSnapToDevicePixels(Rect& aRect, const DrawTarget& aDrawTarget,
+                                    bool aAllowScaleOr90DegreeRotate = false,
+                                    bool aAllowEmptySnaps = true) {
+  if (UserToDevicePixelSnapped(aRect, aDrawTarget, aAllowScaleOr90DegreeRotate,
+                               aAllowEmptySnaps)) {
+    // Since UserToDevicePixelSnapped returned true we know there is no
+    // rotation/skew in 'mat', so we can just use TransformBounds() here.
+    Matrix mat = aDrawTarget.GetTransform();
+    mat.Invert();
+    aRect = mat.TransformBounds(aRect);
+    return true;
+  }
+  return false;
+}
+
+}  // namespace gfx
+}  // namespace mozilla
+
+#endif /* MOZILLA_GFX_PATHHELPERS_H_ */