NAME

cxCoordTransform - apply a homogeneous transformation matrix to all coordinates

C SPECIFICATION

#include <cx/DataAccess.h>

cxCoord *cxCoordTransform( cxCoord *coord, long m, long n, float *mat )

FORTRAN SPECIFICATION

integer function cxCoordTransform(coord, m, n, mat)
integer coord
integer m, n
real    mat

PARAMETERS

coord: The input coordinate structure to which the transformation matrix is to be applied.
m: Leading dimension of the homogeneous transformation matrix mat.
n: Second dimension of the homogeneous transformation matrix mat.
mat: MxN homogeneous transformation matrix.

FUNCTION RETURN VALUE

Returns pointer to new curvilinear coordinates with transformed values.

DESCRIPTION

cxCoordTransform multiplies the transformation matrix mat times the coordinates of each point in the input coord to produce the coordinates of the corresponding output point. The matrix mat deals with homogeneous coordinates, so that the last column of the matrix yields the offset vector for the output; the last row of the matrix is ignored. The calculation of the matrix multiplication computes output coordinates (out) based on input coordinates (in) as follows:

	out(i) = mat(i, N-1)  +  sum    mat(i,j) * in(j)
				j <  N
				j >= 0