telegram/TMessagesProj/jni/rlottie/src/vector/vinterpolator.h
2025-11-22 14:04:28 +01:00

84 lines
2.3 KiB
C++
Executable file

/*
* Copyright (c) 2018 Samsung Electronics Co., Ltd. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef VINTERPOLATOR_H
#define VINTERPOLATOR_H
#include "vpoint.h"
V_BEGIN_NAMESPACE
class VInterpolator {
public:
VInterpolator()
{ /* caller must call Init later */
}
VInterpolator(float aX1, float aY1, float aX2, float aY2)
{
init(aX1, aY1, aX2, aY2);
}
VInterpolator(VPointF pt1, VPointF pt2)
{
init(pt1.x(), pt1.y(), pt2.x(), pt2.y());
}
void init(float aX1, float aY1, float aX2, float aY2);
float value(float aX) const;
void GetSplineDerivativeValues(float aX, float& aDX, float& aDY) const;
private:
void CalcSampleValues();
/**
* Returns x(t) given t, x1, and x2, or y(t) given t, y1, and y2.
*/
static float CalcBezier(float aT, float aA1, float aA2);
/**
* Returns dx/dt given t, x1, and x2, or dy/dt given t, y1, and y2.
*/
static float GetSlope(float aT, float aA1, float aA2);
float GetTForX(float aX) const;
float NewtonRaphsonIterate(float aX, float aGuessT) const;
float BinarySubdivide(float aX, float aA, float aB) const;
static float A(float aA1, float aA2) { return 1.0 - 3.0 * aA2 + 3.0 * aA1; }
static float B(float aA1, float aA2) { return 3.0 * aA2 - 6.0 * aA1; }
static float C(float aA1) { return 3.0 * aA1; }
float mX1;
float mY1;
float mX2;
float mY2;
enum { kSplineTableSize = 11 };
float mSampleValues[kSplineTableSize];
static const float kSampleStepSize;
};
V_END_NAMESPACE
#endif // VINTERPOLATOR_H