File indexing completed on 2024-05-12 15:58:16

 /*
  *  SPDX-FileCopyrightText: 2014 Dmitry Kazakov <dimula73@gmail.com>
  *
  *  SPDX-License-Identifier: GPL-2.0-or-later
  */
 
 #ifndef __KIS_FOUR_POINT_INTERPOLATOR_FORWARD_H
 #define __KIS_FOUR_POINT_INTERPOLATOR_FORWARD_H
 
 #include <QPolygon>
 #include <QPointF>
 
 
 
 /**
  *    A-----B         The polygons must be initialized in this order:
  *    |     |
  *    |     |         polygon << A << B << D << C;
  *    C-----D
  */
 
 class KisFourPointInterpolatorForward
 {
 public:
     KisFourPointInterpolatorForward(const QPolygonF &srcPolygon, const QPolygonF &dstPolygon) {
         m_srcBase = srcPolygon[0];
         m_dstBase = dstPolygon[0];
 
         m_h0 = dstPolygon[1] - dstPolygon[0]; // BA
         m_h1 = dstPolygon[2] - dstPolygon[3]; // DC
 
         m_v0 = dstPolygon[3] - dstPolygon[0]; // CA
 
         m_forwardCoeffX = 1.0 / (srcPolygon[1].x() - srcPolygon[0].x());
         m_forwardCoeffY = 1.0 / (srcPolygon[3].y() - srcPolygon[0].y());
 
         m_xProp = 0;
         m_yProp = 0;
     }
 
     inline QPointF map(const QPointF &pt) {
         setX(pt.x());
         setY(pt.y());
         return getValue();
     }
 
     inline void setX(qreal x) {
         qreal diff = x - m_srcBase.x();
         m_xProp = diff * m_forwardCoeffX;
     }
 
     inline void setY(qreal y) {
         qreal diff = y - m_srcBase.y();
         m_yProp = diff * m_forwardCoeffY;
     }
 
     inline QPointF getValue() const {
         QPointF dstPoint = m_dstBase +
             m_yProp * m_v0 +
             m_xProp * (m_yProp * m_h1 + (1.0 - m_yProp) * m_h0);
 
         return dstPoint;
     }
 
 private:
     QPointF m_srcBase;
     QPointF m_dstBase;
 
     QPointF m_h0;
     QPointF m_h1;
     QPointF m_v0;
 
     qreal m_forwardCoeffX;
     qreal m_forwardCoeffY;
 
     qreal m_xProp;
     qreal m_yProp;
 };
 
 #endif /* __KIS_FOUR_POINT_INTERPOLATOR_FORWARD_H */