/*
 * Written 2003 Lukas Kunc <Lukas.Kunc@seznam.cz>
 *
 * 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.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <stdlib.h>
#include "xmalloc.h"
#include "weights.h"

weights_t* weights_create(weights_t* weights, convmask_t* convmask)
{
	int r, r2, i, j, k, l;
	int rxnz, rynz;
	real_t s;
	int size;

	rxnz = rynz = 0;
	r = convmask->radius;
	weights->r2 = r2 = 2 * r;
	weights->size = size = 2*r2 + 1;
	weights->stride = r2 * (size + 1);
	weights->w = (real_t*)xmalloc(sizeof(real_t) * size * size);

	for (i = 0; i <= r2; i++) {
		for (j = 0; j <= r2; j++) {
			s = R(0.0);
			for (k = -r; k <= r-i; k++) {
				for (l = -r; l <= r-j; l++) {
					s -= convmask_get(convmask, k, l) * convmask_get(convmask, k+i, l+j);
				}
			}
			if (fabs(s) > 1e-6)
			{
				if (i > rxnz) rxnz = i;
				if (j > rynz) rynz = j;
			}
			weights_set(weights,  i,  j, s);
			weights_set(weights, -i, -j, s);

			s = R(0.0);
			for (k = -r; k <= r-i; k++) {
				for (l = -r; l <= r-j; l++) {
					s -= convmask_get(convmask, k, l+j) * convmask_get(convmask, k+i, l);
				}
			}
			if (fabs(s) > 1e-6)
			{
				if (i > rxnz) rxnz = i;
				if (j > rynz) rynz = j;
			}
			weights_set(weights, -i,  j, s);
			weights_set(weights,  i, -j, s);
		}
	}

	weights->rxnz = rxnz;
	weights->rynz = rynz;

	return weights;
}

void weights_destroy(weights_t* weights)
{
	xfree(weights->w);
}

void weights_print(weights_t* weights, FILE* file)
{
	int i, j;
	fprintf(file, "WEIGHTS: (rxnz, rynz)=(%d,%d)\n", weights->rxnz, weights->rynz);
	for (j = -weights->r2; j <= weights->r2; j++)
	{
		for (i = -weights->r2; i <= weights->r2; i++)
		{
			fprintf(file, "%3.3e ", (float)weights_get(weights, i, j));
		}
		fprintf(file, "\n");
	}
}

/*
* GET / SET
*/

#if !defined(INLINE) && !defined(INLINE_MACRO)

real_t weights_get(weights_t* weights, int x, int y)
{
	/*
	* The same as
	* return weights->w[(weights->r2 + y) * weights->size + (weights->r2 + x)];
	*/
	return MACRO_WEIGHTS_GET(weights, x, y);
}

void weights_set(weights_t* weights, int x, int y, real_t value)
{
	/*
	* The same as
	* weights->w[(weights->r2 + y) * weights->size + (weights->r2 + x)] = value;
	*/
	MACRO_WEIGHTS_SET(weights, x, y, value);
	weights->w[weights->stride + y * weights->size + x] = value;
}

#endif