/*
 * Copyright 2011, Blender Foundation.
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * Contributor:
 *		Jeroen Bakker
 *		Monique Dewanchand
 */

#include "COM_GlareSimpleStarOperation.h"

void GlareSimpleStarOperation::generateGlare(float *data, MemoryBuffer *inputTile, NodeGlare *settings)
{
	int i, x, y, ym, yp, xm, xp;
	float c[4] = {0, 0, 0, 0}, tc[4] = {0, 0, 0, 0};
	const float f1 = 1.0f - settings->fade;
	const float f2 = (1.0f - f1) * 0.5f;

	MemoryBuffer *tbuf1 = inputTile->duplicate();
	MemoryBuffer *tbuf2 = inputTile->duplicate();

	bool breaked = false;
	for (i = 0; i < settings->iter && (!breaked); i++) {
//		// (x || x-1, y-1) to (x || x+1, y+1)
//		// F
		for (y = 0; y < this->getHeight() && (!breaked); y++) {
			ym = y - i;
			yp = y + i;
			for (x = 0; x < this->getWidth(); x++) {
				xm = x - i;
				xp = x + i;
				tbuf1->read(c, x, y);
				mul_v3_fl(c, f1);
				tbuf1->read(tc, (settings->star_45 ? xm : x), ym);
				madd_v3_v3fl(c, tc, f2);
				tbuf1->read(tc, (settings->star_45 ? xp : x), yp);
				madd_v3_v3fl(c, tc, f2);
				c[3] = 1.0f;
				tbuf1->writePixel(x, y, c);

				tbuf2->read(c, x, y);
				mul_v3_fl(c, f1);
				tbuf2->read(tc, xm, (settings->star_45 ? yp : y));
				madd_v3_v3fl(c, tc, f2);
				tbuf2->read(tc, xp, (settings->star_45 ? ym : y));
				madd_v3_v3fl(c, tc, f2);
				c[3] = 1.0f;
				tbuf2->writePixel(x, y, c);
			}
			if (isBreaked()) {
				breaked = true;
			}
		}
//		// B
		for (y = this->getHeight() - 1; y >= 0 && (!breaked); y--) {
			ym = y - i;
			yp = y + i;
			for (x = this->getWidth() - 1; x >= 0; x--) {
				xm = x - i;
				xp = x + i;
				tbuf1->read(c, x, y);
				mul_v3_fl(c, f1);
				tbuf1->read(tc, (settings->star_45 ? xm : x), ym);
				madd_v3_v3fl(c, tc, f2);
				tbuf1->read(tc, (settings->star_45 ? xp : x), yp);
				madd_v3_v3fl(c, tc, f2);
				c[3] = 1.0f;
				tbuf1->writePixel(x, y, c);

				tbuf2->read(c, x, y);
				mul_v3_fl(c, f1);
				tbuf2->read(tc, xm, (settings->star_45 ? yp : y));
				madd_v3_v3fl(c, tc, f2);
				tbuf2->read(tc, xp, (settings->star_45 ? ym : y));
				madd_v3_v3fl(c, tc, f2);
				c[3] = 1.0f;
				tbuf2->writePixel(x, y, c);
			}
			if (isBreaked()) {
				breaked = true;
			}
		}
	}

	for (i = 0; i < this->getWidth() * this->getHeight() * 4; i++) {
		data[i] = tbuf1->getBuffer()[i] + tbuf2->getBuffer()[i];
	}

	delete tbuf1;
	delete tbuf2;
}