hackthelobby/libcaca/examples/dithering.c

145 lines
3.7 KiB
C

/*
* dithering libcaca dithering test program
* Copyright (c) 2003-2012 Sam Hocevar <sam@hocevar.net>
* All Rights Reserved
*
* This program is free software. It comes without any warranty, to
* the extent permitted by applicable law. You can redistribute it
* and/or modify it under the terms of the Do What the Fuck You Want
* to Public License, Version 2, as published by Sam Hocevar. See
* http://www.wtfpl.net/ for more details.
*/
#include "config.h"
#if !defined(__KERNEL__)
# include <stdio.h>
#endif
#include "caca.h"
#define XRATIO 100*100
#define YRATIO 70*70
#define FUZZY 5000000
unsigned int points[] =
{
CACA_BLACK, CACA_DARKGRAY, CACA_LIGHTGRAY,
CACA_WHITE, CACA_RED, CACA_LIGHTRED
};
char density[] = " ',+:;o&%w$W@#";
int main(int argc, char *argv[])
{
caca_canvas_t *cv;
caca_display_t *dp;
int neara, dista, nearb, distb, dist;
int x, y;
cv = caca_create_canvas(80, 24);
if(cv == NULL)
{
printf("Failed to create canvas\n");
return 1;
}
dp = caca_create_display(cv);
if(dp == NULL)
{
printf("Failed to create display\n");
return 1;
}
for(x = 0; x < 100; x++)
for(y = 0; y < 100; y++)
{
char ch = '?';
/* distance to black */
dista = XRATIO * x * x;
neara = 0;
/* distance to 40% */
dist = XRATIO * (x - 40) * (x - 40) + YRATIO * y * y;
if(caca_rand(-FUZZY, FUZZY+1) + dist < dista)
{
nearb = neara; distb = dista; neara = 1; dista = dist;
}
else
{
nearb = 1; distb = dist;
}
/* check dist to 70% */
dist = XRATIO * (x - 70) * (x - 70) + YRATIO * y * y;
if(caca_rand(-FUZZY, FUZZY+1) + dist < dista)
{
nearb = neara; distb = dista; neara = 2; dista = dist;
}
else if(caca_rand(-FUZZY, FUZZY+1) + dist < distb)
{
nearb = 2; distb = dist;
}
/* check dist to white */
dist = XRATIO * (x - 100) * (x - 100) + YRATIO * y * y;
if(caca_rand(-FUZZY, FUZZY+1) + dist < dista)
{
nearb = neara; distb = dista; neara = 3; dista = dist;
}
else if(caca_rand(-FUZZY, FUZZY+1) + dist < distb)
{
nearb = 3; distb = dist;
}
#if 1
/* check dist to dark */
dist = XRATIO * (x - 40) * (x - 40) + YRATIO * (y - 100) * (y - 100);
dist = dist * 12 / 16;
if(caca_rand(-FUZZY, FUZZY+1) + dist < dista)
{
nearb = neara; distb = dista; neara = 4; dista = dist;
}
else if(caca_rand(-FUZZY, FUZZY+1) + dist < distb)
{
nearb = 4; distb = dist;
}
/* check dist to light */
dist = XRATIO * (x - 100) * (x - 100) + YRATIO * (y - 100) * (y - 100);
dist = dist * 8 / 16;
if(caca_rand(-FUZZY, FUZZY+1) + dist < dista)
{
nearb = neara; distb = dista; neara = 5; dista = dist;
}
else if(caca_rand(-FUZZY, FUZZY+1) + dist < distb)
{
nearb = 5; distb = dist;
}
#endif
/* dista can be > distb because of dithering fuzziness */
if(dista > distb)
ch = density[distb * 2 * 13 / (dista + distb)];
else
ch = density[dista * 2 * 13 / (dista + distb)];
caca_set_color_ansi(cv, points[nearb], points[neara]);
caca_put_char(cv, x * caca_get_canvas_width(cv) / 100,
(100 - y) * caca_get_canvas_height(cv) / 100, ch);
}
caca_refresh_display(dp);
caca_get_event(dp, CACA_EVENT_KEY_PRESS, NULL, -1);
caca_free_display(dp);
caca_free_canvas(cv);
return 0;
}