Index: third_party/WebKit/Source/platform/animation/UnitBezier.h |
diff --git a/third_party/WebKit/Source/platform/animation/UnitBezier.h b/third_party/WebKit/Source/platform/animation/UnitBezier.h |
index dc0db721161a5544d088f649185943b22ddc60a6..bd4c64802bfe81fae2173a48ca0610321e695fa6 100644 |
--- a/third_party/WebKit/Source/platform/animation/UnitBezier.h |
+++ b/third_party/WebKit/Source/platform/animation/UnitBezier.h |
@@ -1,169 +1,49 @@ |
-/* |
- * Copyright (C) 2008 Apple Inc. All Rights Reserved. |
- * |
- * Redistribution and use in source and binary forms, with or without |
- * modification, are permitted provided that the following conditions |
- * are met: |
- * 1. Redistributions of source code must retain the above copyright |
- * notice, this list of conditions and the following disclaimer. |
- * 2. Redistributions in binary form must reproduce the above copyright |
- * notice, this list of conditions and the following disclaimer in the |
- * documentation and/or other materials provided with the distribution. |
- * |
- * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY |
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR |
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY |
- * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
- */ |
+// Copyright 2016 The Chromium Authors. All rights reserved. |
+// Use of this source code is governed by a BSD-style license that can be |
+// found in the LICENSE file. |
#ifndef UnitBezier_h |
#define UnitBezier_h |
-#include "platform/PlatformExport.h" |
+#include "ui/gfx/geometry/cubic_bezier.h" |
#include "wtf/Allocator.h" |
-#include "wtf/Assertions.h" |
- |
-#include <algorithm> |
-#include <cmath> |
namespace blink { |
-struct PLATFORM_EXPORT UnitBezier { |
+// TODO(loyso): Erase blink::UnitBezier and use gfx::CubicBezier directly. |
+struct UnitBezier { |
USING_FAST_MALLOC(UnitBezier); |
public: |
- UnitBezier(double p1x, double p1y, double p2x, double p2y); |
- |
- static const double kBezierEpsilon; |
- |
- double sampleCurveX(double t) const |
- { |
- // `ax t^3 + bx t^2 + cx t' expanded using Horner's rule. |
- return ((ax * t + bx) * t + cx) * t; |
- } |
- |
- double sampleCurveY(double t) const |
+ UnitBezier(double p1x, double p1y, double p2x, double p2y) |
+ : m_cubicBezier(p1x, p1y, p2x, p2y) |
{ |
- return ((ay * t + by) * t + cy) * t; |
} |
- double sampleCurveDerivativeX(double t) const |
+ double sampleCurveX(double t) const |
{ |
- return (3.0 * ax * t + 2.0 * bx) * t + cx; |
+ return m_cubicBezier.SampleCurveX(t); |
} |
- double sampleCurveDerivativeY(double t) const |
+ double sampleCurveY(double t) const |
{ |
- return (3.0 * ay * t + 2.0 * by) * t + cy; |
- } |
- |
- // Given an x value, find a parametric value it came from. |
- double solveCurveX(double x, double epsilon) const |
- { |
- ASSERT(x >= 0.0); |
- ASSERT(x <= 1.0); |
- |
- double t0; |
- double t1; |
- double t2; |
- double x2; |
- double d2; |
- int i; |
- |
- // First try a few iterations of Newton's method -- normally very fast. |
- for (t2 = x, i = 0; i < 8; i++) { |
- x2 = sampleCurveX(t2) - x; |
- if (fabs (x2) < epsilon) |
- return t2; |
- d2 = sampleCurveDerivativeX(t2); |
- if (fabs(d2) < 1e-6) |
- break; |
- t2 = t2 - x2 / d2; |
- } |
- |
- // Fall back to the bisection method for reliability. |
- t0 = 0.0; |
- t1 = 1.0; |
- t2 = x; |
- |
- while (t0 < t1) { |
- x2 = sampleCurveX(t2); |
- if (fabs(x2 - x) < epsilon) |
- return t2; |
- if (x > x2) |
- t0 = t2; |
- else |
- t1 = t2; |
- t2 = (t1 - t0) * .5 + t0; |
- } |
- |
- // Failure. |
- return t2; |
+ return m_cubicBezier.SampleCurveY(t); |
} |
// Evaluates y at the given x. |
double solve(double x) const |
{ |
- return solveWithEpsilon(x, kBezierEpsilon); |
+ return m_cubicBezier.Solve(x); |
} |
// Evaluates y at the given x. The epsilon parameter provides a hint as to the required |
// accuracy and is not guaranteed. |
double solveWithEpsilon(double x, double epsilon) const |
{ |
- if (x < 0.0) |
- return 0.0 + m_startGradient * x; |
- if (x > 1.0) |
- return 1.0 + m_endGradient * (x - 1.0); |
- return sampleCurveY(solveCurveX(x, epsilon)); |
- } |
- |
- // Returns an approximation of dy/dx at the given x. |
- double slope(double x) const |
- { |
- return slopeWithEpsilon(x, kBezierEpsilon); |
- } |
- |
- double slopeWithEpsilon(double x, double epsilon) const |
- { |
- double t = solveCurveX(x, epsilon); |
- double dx = sampleCurveDerivativeX(t); |
- double dy = sampleCurveDerivativeY(t); |
- return dy / dx; |
- } |
- |
- // Sets |min| and |max| to the bezier's minimum and maximium y values in the |
- // interval [0, 1]. |
- void range(double* min, double* max) const |
- { |
- *min = m_rangeMin; |
- *max = m_rangeMax; |
+ return m_cubicBezier.SolveWithEpsilon(x, epsilon); |
} |
private: |
- void initCoefficients(double p1x, double p1y, double p2x, double p2y); |
- void initGradients(double p1x, double p1y, double p2x, double p2y); |
- void initRange(double p1y, double p2y); |
- |
- double ax; |
- double bx; |
- double cx; |
- |
- double ay; |
- double by; |
- double cy; |
- |
- double m_startGradient; |
- double m_endGradient; |
- |
- double m_rangeMin; |
- double m_rangeMax; |
+ gfx::CubicBezier m_cubicBezier; |
}; |
} // namespace blink |