123 lines
3.0 KiB
C++
123 lines
3.0 KiB
C++
/* -*- 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 NS_SMILKEYSPLINE_H_
|
|
#define NS_SMILKEYSPLINE_H_
|
|
|
|
#include "mozilla/ArrayUtils.h"
|
|
#include "mozilla/PodOperations.h"
|
|
|
|
/**
|
|
* Utility class to provide scaling defined in a keySplines element.
|
|
*/
|
|
class nsSMILKeySpline
|
|
{
|
|
public:
|
|
nsSMILKeySpline() { /* caller must call Init later */ }
|
|
|
|
/**
|
|
* Creates a new key spline control point description.
|
|
*
|
|
* aX1, etc. are the x1, y1, x2, y2 cubic Bezier control points as defined by
|
|
* SMILANIM 3.2.3. They must each be in the range 0.0 <= x <= 1.0
|
|
*/
|
|
nsSMILKeySpline(double aX1, double aY1,
|
|
double aX2, double aY2)
|
|
{
|
|
Init(aX1, aY1, aX2, aY2);
|
|
}
|
|
|
|
double X1() const { return mX1; }
|
|
double Y1() const { return mY1; }
|
|
double X2() const { return mX2; }
|
|
double Y2() const { return mY2; }
|
|
|
|
void Init(double aX1, double aY1,
|
|
double aX2, double aY2);
|
|
|
|
/**
|
|
* Gets the output (y) value for an input (x).
|
|
*
|
|
* @param aX The input x value. A floating-point number between 0 and
|
|
* 1 (inclusive).
|
|
*/
|
|
double GetSplineValue(double aX) const;
|
|
|
|
void GetSplineDerivativeValues(double aX, double& aDX, double& aDY) const;
|
|
|
|
bool operator==(const nsSMILKeySpline& aOther) const {
|
|
return mX1 == aOther.mX1 &&
|
|
mY1 == aOther.mY1 &&
|
|
mX2 == aOther.mX2 &&
|
|
mY2 == aOther.mY2;
|
|
}
|
|
bool operator!=(const nsSMILKeySpline& aOther) const {
|
|
return !(*this == aOther);
|
|
}
|
|
int32_t Compare(const nsSMILKeySpline& aRhs) const {
|
|
if (mX1 != aRhs.mX1) return mX1 < aRhs.mX1 ? -1 : 1;
|
|
if (mY1 != aRhs.mY1) return mY1 < aRhs.mY1 ? -1 : 1;
|
|
if (mX2 != aRhs.mX2) return mX2 < aRhs.mX2 ? -1 : 1;
|
|
if (mY2 != aRhs.mY2) return mY2 < aRhs.mY2 ? -1 : 1;
|
|
return 0;
|
|
}
|
|
|
|
private:
|
|
void
|
|
CalcSampleValues();
|
|
|
|
/**
|
|
* Returns x(t) given t, x1, and x2, or y(t) given t, y1, and y2.
|
|
*/
|
|
static double
|
|
CalcBezier(double aT, double aA1, double aA2);
|
|
|
|
/**
|
|
* Returns dx/dt given t, x1, and x2, or dy/dt given t, y1, and y2.
|
|
*/
|
|
static double
|
|
GetSlope(double aT, double aA1, double aA2);
|
|
|
|
double
|
|
GetTForX(double aX) const;
|
|
|
|
double
|
|
NewtonRaphsonIterate(double aX, double aGuessT) const;
|
|
|
|
double
|
|
BinarySubdivide(double aX, double aA, double aB) const;
|
|
|
|
static double
|
|
A(double aA1, double aA2)
|
|
{
|
|
return 1.0 - 3.0 * aA2 + 3.0 * aA1;
|
|
}
|
|
|
|
static double
|
|
B(double aA1, double aA2)
|
|
{
|
|
return 3.0 * aA2 - 6.0 * aA1;
|
|
}
|
|
|
|
static double
|
|
C(double aA1)
|
|
{
|
|
return 3.0 * aA1;
|
|
}
|
|
|
|
double mX1;
|
|
double mY1;
|
|
double mX2;
|
|
double mY2;
|
|
|
|
enum { kSplineTableSize = 11 };
|
|
double mSampleValues[kSplineTableSize];
|
|
|
|
static const double kSampleStepSize;
|
|
};
|
|
|
|
#endif // NS_SMILKEYSPLINE_H_
|