1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/dom/smil/nsSMILKeySpline.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,101 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef NS_SMILKEYSPLINE_H_
1.10 +#define NS_SMILKEYSPLINE_H_
1.11 +
1.12 +/**
1.13 + * Utility class to provide scaling defined in a keySplines element.
1.14 + */
1.15 +class nsSMILKeySpline
1.16 +{
1.17 +public:
1.18 + nsSMILKeySpline() { /* caller must call Init later */ }
1.19 +
1.20 + /**
1.21 + * Creates a new key spline control point description.
1.22 + *
1.23 + * aX1, etc. are the x1, y1, x2, y2 cubic Bezier control points as defined by
1.24 + * SMILANIM 3.2.3. They must each be in the range 0.0 <= x <= 1.0
1.25 + */
1.26 + nsSMILKeySpline(double aX1, double aY1,
1.27 + double aX2, double aY2)
1.28 + {
1.29 + Init(aX1, aY1, aX2, aY2);
1.30 + }
1.31 +
1.32 + double X1() const { return mX1; }
1.33 + double Y1() const { return mY1; }
1.34 + double X2() const { return mX2; }
1.35 + double Y2() const { return mY2; }
1.36 +
1.37 + void Init(double aX1, double aY1,
1.38 + double aX2, double aY2);
1.39 +
1.40 + /**
1.41 + * Gets the output (y) value for an input (x).
1.42 + *
1.43 + * @param aX The input x value. A floating-point number between 0 and
1.44 + * 1 (inclusive).
1.45 + */
1.46 + double GetSplineValue(double aX) const;
1.47 +
1.48 + void GetSplineDerivativeValues(double aX, double& aDX, double& aDY) const;
1.49 +
1.50 +private:
1.51 + void
1.52 + CalcSampleValues();
1.53 +
1.54 + /**
1.55 + * Returns x(t) given t, x1, and x2, or y(t) given t, y1, and y2.
1.56 + */
1.57 + static double
1.58 + CalcBezier(double aT, double aA1, double aA2);
1.59 +
1.60 + /**
1.61 + * Returns dx/dt given t, x1, and x2, or dy/dt given t, y1, and y2.
1.62 + */
1.63 + static double
1.64 + GetSlope(double aT, double aA1, double aA2);
1.65 +
1.66 + double
1.67 + GetTForX(double aX) const;
1.68 +
1.69 + double
1.70 + NewtonRaphsonIterate(double aX, double aGuessT) const;
1.71 +
1.72 + double
1.73 + BinarySubdivide(double aX, double aA, double aB) const;
1.74 +
1.75 + static double
1.76 + A(double aA1, double aA2)
1.77 + {
1.78 + return 1.0 - 3.0 * aA2 + 3.0 * aA1;
1.79 + }
1.80 +
1.81 + static double
1.82 + B(double aA1, double aA2)
1.83 + {
1.84 + return 3.0 * aA2 - 6.0 * aA1;
1.85 + }
1.86 +
1.87 + static double
1.88 + C(double aA1)
1.89 + {
1.90 + return 3.0 * aA1;
1.91 + }
1.92 +
1.93 + double mX1;
1.94 + double mY1;
1.95 + double mX2;
1.96 + double mY2;
1.97 +
1.98 + enum { kSplineTableSize = 11 };
1.99 + double mSampleValues[kSplineTableSize];
1.100 +
1.101 + static const double kSampleStepSize;
1.102 +};
1.103 +
1.104 +#endif // NS_SMILKEYSPLINE_H_
