/* 
 * Linux VeeJay
 *
 * Copyright(C)2023 Niels Elburg <nwelburg@gmail.com>
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307 , USA.
 */

#include "common.h"
#include <veejaycore/vjmem.h>
#include "rainbowshift.h"

vj_effect *rainbowshift_init(int w, int h)
{
    vj_effect *ve = (vj_effect *) vj_calloc(sizeof(vj_effect));
    ve->num_params = 2;

    ve->defaults = (int *) vj_calloc(sizeof(int) * ve->num_params);	/* default values */
    ve->limits[0] = (int *) vj_calloc(sizeof(int) * ve->num_params);	/* min */
    ve->limits[1] = (int *) vj_calloc(sizeof(int) * ve->num_params);	/* max */
    ve->limits[0][0] = 0;
    ve->limits[1][0] = 255;
	ve->limits[0][1] = 0;
    ve->limits[1][1] = 10;
    ve->defaults[0] = 1;
	ve->defaults[1] = 1;
    ve->description = "Rainbow Shift";
    ve->sub_format = 1;
    ve->extra_frame = 0;
    ve->parallel = 1;
    ve->has_user = 0;
    ve->param_description = vje_build_param_list( ve->num_params, "Amplitude", "Frequency" );
    return ve;
}


void rainbowshift_apply( void *ptr, VJFrame *frame, int *args ) {
    int shift_amplitude = args[0];
	int shift_frequency = args[1];

    int i;
    const int len = frame->len;

    uint8_t *Y = frame->data[0];
    uint8_t *Cb = frame->data[1];
    uint8_t *Cr = frame->data[2];
/*
	for( i = 0; i < len; i ++ ) {
		int shift = (Y[i] * shift_factor) >> 8;

		Cb[i] = ( Cb[i] + shift ) & 255;
		Cr[i] = ( Cr[i] - shift ) & 255;
	}
*/

	
	for (i = 0; i < len; i++) {
        double wave_shift = shift_amplitude * a_sin(2 * M_PI * shift_frequency * i / len);

        Cb[i] = (Cb[i] + (int)wave_shift) & 255;
        Cr[i] = (Cr[i] - (int)wave_shift) & 255;
        Y[i] = (Y[i] + (int)wave_shift) & 255;
    }
}