/*
 * matrix.h - 2D matrix operations
 *
 * Written 2010 by Werner Almesberger
 * Copyright 2010 by Werner Almesberger
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#ifndef MATRIX_H
#define MATRIX_H

/*
 * 2D transformation:
 *
 * x' = x*a[0][0]+y*a[0][1]+b[0]
 * y' = x*a[1][0]+y*a[1][1]+b[1]
 */


struct matrix {
	double a[2][2];
	double b[2];
};


void matrix_identity(struct matrix *m);
void matrix_invert(const double m[2][2], double res[2][2]);
void matrix_mult(double a[2][2], double b[2][2], double res[2][2]);
void matrix_multv(const double v[2], double m[2][2], double res[2]);
void matrix_copy(double from[2][2], double to[2][2]);


static inline void matrix_map(int x, int y, const struct matrix *m,
    double *res_x, double *res_y)
{
	*res_x = x*m->a[0][0]+y*m->a[0][1]+m->b[0];
	*res_y = x*m->a[1][0]+y*m->a[1][1]+m->b[1];

}

#endif /* !MATRIX_H */