r641: no message

[ctsim.git] / include / interpolator.h

diff --git a/include/interpolator.h b/include/interpolator.h
index def913ec377161f40e86e7765fb24f1faf605cbe..cea4961809cda3300db2c8b227d7639c3d1d734e 100644 (file)
--- a/include/interpolator.h
+++ b/include/interpolator.h
@@ -2,7 +2,7 @@
 **  This is part of the CTSim program
 **  Copyright (c) 1983-2001 Kevin Rosenberg
 **
 **  This is part of the CTSim program
 **  Copyright (c) 1983-2001 Kevin Rosenberg
 **

-**  $Id: interpolator.h,v 1.1 2001/02/11 21:57:08 kevin Exp $
+**  $Id: interpolator.h,v 1.2 2001/03/21 21:45:31 kevin Exp $

 **
 **  This program is free software; you can redistribute it and/or modify
 **  it under the terms of the GNU General Public License (version 2) as
 **
 **  This program is free software; you can redistribute it and/or modify
 **  it under the terms of the GNU General Public License (version 2) as


@@ -47,3 +47,114 @@ public:
   double interpolate (double x);
 };
 
   double interpolate (double x);
 };
 

+
+template<class T>
+class BilinearInterpolator {
+private:
+  T** const m_ppMatrix;
+  const unsigned int m_nx;
+  const unsigned int m_ny;
+
+public:
+  BilinearInterpolator (T** ppMatrix, unsigned int nx, unsigned int ny)
+  : m_ppMatrix(ppMatrix), m_nx(nx), m_ny(ny)
+  {}
+  
+  T interpolate (double dXPos, double dYPos)
+  {
+    int iFloorX = floor (dXPos);
+    int iFloorY = floor (dYPos);
+    double dXFrac = dXPos - iFloorX;
+    double dYFrac = dYPos - iFloorY;
+
+    T result = 0;
+
+    if (iFloorX < 0 || iFloorY < 0 || iFloorX > m_nx-1 || iFloorY > m_ny-1)
+      result = 0;
+    else if (iFloorX == m_nx - 1 && iFloorY == m_ny - 1)
+      result = m_ppMatrix[m_nx-1][m_ny-1];
+    else if (iFloorX == m_nx - 1)
+      result = m_ppMatrix[iFloorX][iFloorY] + dYFrac * (m_ppMatrix[iFloorX][iFloorY+1] - m_ppMatrix[iFloorX][iFloorY]);
+    else if (iFloorY == m_ny - 1)
+      result = m_ppMatrix[iFloorX][iFloorY] + dXFrac * (m_ppMatrix[iFloorX+1][iFloorY] - m_ppMatrix[iFloorX][iFloorY]);
+    else
+      result = (1 - dXFrac) * (1 - dYFrac) * m_ppMatrix[iFloorX][iFloorY] + 
+        dXFrac * (1 - dYFrac) * m_ppMatrix[iFloorX+1][iFloorY] + 
+        dYFrac * (1 - dXFrac) * m_ppMatrix[iFloorX][iFloorY+1] +
+        dXFrac * dYFrac * m_ppMatrix[iFloorX+1][iFloorY+1];
+
+    return result;
+  }
+};
+
+
+template<class T>
+class LinearInterpolator {
+private:
+  T* const m_pY;
+  T* const m_pX;
+  const unsigned int m_n;
+
+public:
+  LinearInterpolator (T* pY, unsigned int n)
+  : m_pY(pY), m_pX(0), m_n(n)
+  {}
+  
+  LinearInterpolator (T* pY, T* pX, unsigned int n)
+  : m_pY(pY), m_pX(pX), m_n(n)
+  {}
+  
+  double interpolate (double dX, int* piLastFloor = NULL)
+  {
+    double result = 0;
+
+    if (! m_pX) {
+      if (dX == 0)
+        result = m_pY[0];
+      else if (dX < 0)
+        result = 0;
+      else if (dX == m_n - 1)
+        result = m_pY[m_n-1];
+      else if (dX > m_n - 1)
+        result = 0;
+      else {
+       int iFloor = floor(dX);
+       result = m_pY[iFloor] + (m_pY[iFloor+1] - m_pY[iFloor]) * (dX - iFloor);
+      }
+    } else {
+      int iLower = -1;
+      int iUpper = m_n;
+      if (piLastFloor && *piLastFloor >= 0 && m_pX[*piLastFloor] < dX)
+        iLower = *piLastFloor;
+
+      while (iUpper - iLower > 1) {
+        int iMiddle = (iUpper + iLower) >> 1;
+        if (dX >= m_pX[iMiddle])
+          iLower = iMiddle;
+        else
+          iUpper = iMiddle;
+      }
+      if (dX == m_pX[0])
+        result = m_pY[0];
+      else if (dX < m_pX[0])
+        result = 0;
+      else if (dX == m_pX[m_n-1])
+        result = m_pY[m_n-1];
+      else if (dX > m_pX[m_n-1])
+        result = 0;
+      else {
+        if (iLower < 0 || iLower >= m_n) {
+          sys_error (ERR_SEVERE, "Coordinate out of range [linearInterpolate]");
+          return 0;
+        }
+
+       if (piLastFloor)
+         *piLastFloor = iLower;
+       result = m_pY[iLower] + (m_pY[iUpper] - m_pY[iLower]) * ((dX - m_pX[iLower]) / (m_pX[iUpper] - m_pX[iLower]));
+      }
+    }
+
+    return result;
+  }
+};
+