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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:22:09 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 09:22:09 +0000
commit43a97878ce14b72f0981164f87f2e35e14151312 (patch)
tree620249daf56c0258faa40cbdcf9cfba06de2a846 /gfx/2d/BezierUtils.h
parentInitial commit. (diff)
downloadfirefox-upstream.tar.xz
firefox-upstream.zip
Adding upstream version 110.0.1.upstream/110.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'gfx/2d/BezierUtils.h')
-rw-r--r--gfx/2d/BezierUtils.h186
1 files changed, 186 insertions, 0 deletions
diff --git a/gfx/2d/BezierUtils.h b/gfx/2d/BezierUtils.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_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_ */