Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

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

1 files changed, 186 insertions, 0 deletions

diff --git a/gfx/2d/BezierUtils.h b/gfx/2d/BezierUtils.h
new file mode 100644
index 0000000000..3ffcd70214
--- /dev/null
+++ b/gfx/2d/BezierUtils.h
@@ -0,0 +1,186 @@
+/* -*- 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_BezierUtils_h_
+#define mozilla_BezierUtils_h_
+
+#include "mozilla/gfx/Point.h"
+#include "mozilla/gfx/Types.h"
+
+namespace mozilla {
+namespace gfx {
+
+// Control points for bezier curve
+//
+//                   mPoints[2]
+//                    +-----___---+ mPoints[3]
+//                      __--
+//                   _--
+//                  /
+//                /
+// mPoints[1] +  |
+//            | |
+//            ||
+//            ||
+//            |
+//            |
+//            |
+//            |
+// mPoints[0] +
+struct Bezier {
+  Point mPoints[4];
+};
+
+// Calculate a point or it's differential of a bezier curve formed by
+// aBezier and parameter t.
+//
+//   GetBezierPoint = P(t)
+//   GetBezierDifferential = P'(t)
+//   GetBezierDifferential2 = P''(t)
+//
+//                   mPoints[2]
+//                    +-----___---+ mPoints[3]
+//                      __--     P(1)
+//                   _--
+//                  +
+//                /  P(t)
+// mPoints[1] +  |
+//            | |
+//            ||
+//            ||
+//            |
+//            |
+//            |
+//            |
+// mPoints[0] + P(0)
+Point GetBezierPoint(const Bezier& aBezier, Float t);
+Point GetBezierDifferential(const Bezier& aBezier, Float t);
+Point GetBezierDifferential2(const Bezier& aBezier, Float t);
+
+// Calculate length of a simple bezier curve formed by aBezier and range [a, b].
+Float GetBezierLength(const Bezier& aBezier, Float a, Float b);
+
+// Split bezier curve formed by aBezier into [0,t1], [t1,t2], [t2,1] parts, and
+// stores control points for [t1,t2] to aSubBezier.
+//
+//                 ___---+
+//             __+-     P(1)
+//          _--   P(t2)
+//         -
+//       /  <-- aSubBezier
+//      |
+//     |
+//    +
+//    | P(t1)
+//   |
+//   |
+//   |
+//   |
+//   + P(0)
+void GetSubBezier(Bezier* aSubBezier, const Bezier& aBezier, Float t1,
+                  Float t2);
+
+// Find a nearest point on bezier curve formed by aBezier to a point aTarget.
+// aInitialT is a hint to find the parameter t for the nearest point.
+// If aT is non-null, parameter for the nearest point is stored to *aT.
+// This function expects a bezier curve to be an approximation of elliptic arc.
+// Otherwise it will return wrong point.
+//
+//  aTarget
+//    +            ___---+
+//             __--
+//          _--
+//         +
+//       /  nearest point = P(t = *aT)
+//      |
+//     |
+//    |
+//    + P(aInitialT)
+//   |
+//   |
+//   |
+//   |
+//   +
+Point FindBezierNearestPoint(const Bezier& aBezier, const Point& aTarget,
+                             Float aInitialT, Float* aT = nullptr);
+
+// Calculate control points for a bezier curve that is an approximation of
+// an elliptic arc.
+//
+//                                   aCornerSize.width
+//                                 |<----------------->|
+//                                 |                   |
+//                     aCornerPoint|      mPoints[2]   |
+//                    -------------+-------+-----___---+ mPoints[3]
+//                    ^            |         __--
+//                    |            |      _--
+//                    |            |     -
+//                    |            |   /
+// aCornerSize.height | mPoints[1] +  |
+//                    |            | |
+//                    |            ||
+//                    |            ||
+//                    |            |
+//                    |            |
+//                    |            |
+//                    v mPoints[0] |
+//                    -------------+
+void GetBezierPointsForCorner(Bezier* aBezier, mozilla::Corner aCorner,
+                              const Point& aCornerPoint,
+                              const Size& aCornerSize);
+
+// Calculate the approximate length of a quarter elliptic arc formed by radii
+// (a, b).
+//
+//                a
+//      |<----------------->|
+//      |                   |
+//   ---+-------------___---+
+//   ^  |         __--
+//   |  |      _--
+//   |  |     -
+//   |  |   /
+// b |  |  |
+//   |  | |
+//   |  ||
+//   |  ||
+//   |  |
+//   |  |
+//   |  |
+//   v  |
+//   ---+
+Float GetQuarterEllipticArcLength(Float a, Float b);
+
+// Calculate the distance between an elliptic arc formed by (origin, width,
+// height), and a point P, along a line formed by |P + n * normal|.
+// P should be outside of the ellipse, and the line should cross with the
+// ellipse twice at n > 0 points.
+//
+//                            width
+//                     |<----------------->|
+//              origin |                   |
+//          -----------+-------------___---+
+//          ^  normal  |         __--
+//          | P +->__  |      _--
+//          |        --__    -
+//          |          | --+
+//   height |          |  |
+//          |          | |
+//          |          ||
+//          |          ||
+//          |          |
+//          |          |
+//          |          |
+//          v          |
+//          -----------+
+Float CalculateDistanceToEllipticArc(const Point& P, const Point& normal,
+                                     const Point& origin, Float width,
+                                     Float height);
+
+}  // namespace gfx
+}  // namespace mozilla
+
+#endif /* mozilla_BezierUtils_h_ */