/*
 * EffecTV - Realtime Digital Video Effector
 * Copyright (C) 2001-2003 FUKUCHI Kentaro
 *
 * diff.c: color independant differencing.  Just a little test.
 *  copyright (c) 2001 Sam Mertens.  This code is subject to the provisions of
 *  the GNU Public License.
 *
 * Controls:
 *      c   -   lower tolerance (threshhold)
 *      v   -   increase tolerance (threshhold)
 *
 */

#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "EffecTV.h"
#include "utils.h"

#ifndef max
#define max(a,b)    (((a) > (b)) ? (a) : (b))
#endif

#define TOLERANCE_STEP  4

static int start(void);
static int stop(void);
static int draw(RGB32 *src, RGB32 *dest);
//static int event();
//static void diffUpdate();
//static void diffSave();
static char *effectname = "DiffTV";
static int state = 0;

static RGB32* prevbuf;

static int g_tolerance[3] = {10, 10, 10};

effect *diffRegister()
{
	effect *entry;

	sharedbuffer_reset();
	prevbuf = (RGB32*)sharedbuffer_alloc(video_area * PIXEL_SIZE);
	if(prevbuf == NULL) {
		return NULL;
	}

	entry = (effect *)malloc(sizeof(effect));
	if(entry == NULL) {
		return NULL;
	}

	entry->name = effectname;
	entry->start = start;
	entry->stop = stop;
	entry->draw = draw;
	//entry->event = event;

	return entry;
}

static int start()
{
    
#ifdef DEBUG 
    v4lprint(&vd);
#endif

	memset(prevbuf, 0, video_area * PIXEL_SIZE);
    state = 1;
	return 0;
}

static int stop()
{
	state = 0;
	return 0;
}

static int draw(RGB32 *src, RGB32 *dest)
{
    int i;
    int x,y;
    unsigned int src_red, src_grn, src_blu;
    unsigned int old_red, old_grn, old_blu;
    unsigned int red_val, red_diff, grn_val, grn_diff, blu_val, blu_diff;
    
    i = 0;
    for (y = 0; y < video_height; y++)
    {
        for (x = 0; x < video_width; x++)
        {
            // MMX would just eat this algorithm up
            src_red = (src[i] & 0x00FF0000) >> 16;
            src_grn = (src[i] & 0x0000FF00) >> 8;
            src_blu = (src[i] & 0x000000FF);

            old_red = (prevbuf[i] & 0x00FF0000) >> 16;
            old_grn = (prevbuf[i] & 0x0000FF00) >> 8;
            old_blu = (prevbuf[i] & 0x000000FF);

            // RED
            if (src_red > old_red)
            {
                red_val = 0xFF;
                red_diff = src_red - old_red;
            }
            else
            {
                red_val = 0x7F;
                red_diff = old_red - src_red;
            }
            red_val = (red_diff >= g_tolerance[0]) ? red_val : 0x00;

            // GREEN
            if (src_grn > old_grn)
            {
                grn_val = 0xFF;
                grn_diff = src_grn - old_grn;
            }
            else
            {
                grn_val = 0x7F;
                grn_diff = old_grn - src_grn;
            }
            grn_val = (grn_diff >= g_tolerance[1]) ? grn_val : 0x00;
            
            // BLUE
            if (src_blu > old_blu)
            {
                blu_val = 0xFF;
                blu_diff = src_blu - old_blu;
            }
            else
            {
                blu_val = 0x7F;
                blu_diff = old_blu - src_blu;
            }
            blu_val = (blu_diff >= g_tolerance[2]) ? blu_val : 0x00;

            prevbuf[i] = (( ((src_red + old_red) >> 1) << 16) +
                          ( ((src_grn + old_grn) >> 1) << 8) +
                          ( ((src_blu + old_blu) >> 1) ) );

#if 0            
            if ((0x00 != blu_val) && (0x00 != grn_val) && (0x00 != red_val))
            {
                dest[i] = src[i];
            }
            else
            {
                dest[i] = prevbuf[i];
            }
#else            
            dest[i] = (red_val << 16) + (grn_val << 8) + blu_val;
#endif
            
 //x            dest[i] = (red_diff << 17) + (grn_diff << 9) + (blu_diff << 1);

            
//            prevbuf[i] = src[i];    // Since we're already iterating through both of them...

            i++;
        }
    }

	return 0;
}