source: ttyvaders/trunk/libee/conic.c @ 130

Last change on this file since 130 was 130, checked in by Sam Hocevar, 17 years ago
  • Renamed libee/circle.c to libee/conic.c because we'll do ellipsis.
  • Property svn:keywords set to Id
File size: 1.5 KB
Line 
1/*
2 *   libee         ASCII-Art library
3 *   Copyright (c) 2002, 2003 Sam Hocevar <sam@zoy.org>
4 *                 All Rights Reserved
5 *
6 *   $Id: conic.c 130 2003-11-10 15:31:12Z sam $
7 *
8 *   This program is free software; you can redistribute it and/or modify
9 *   it under the terms of the GNU General Public License as published by
10 *   the Free Software Foundation; either version 2 of the License, or
11 *   (at your option) any later version.
12 *
13 *   This program is distributed in the hope that it will be useful,
14 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
15 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 *   GNU General Public License for more details.
17 *
18 *   You should have received a copy of the GNU General Public License
19 *   along with this program; if not, write to the Free Software
20 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 */
22
23#include "config.h"
24
25#include <stdlib.h>
26
27#include "ee.h"
28
29void ee_draw_circle(int x, int y, int r, char c)
30{
31    int test, dx, dy;
32
33    /* Optimized Bresenham. Kick ass. */
34    for(test = 0, dx = 0, dy = r ; dx <= dy ; dx++)
35    {
36        ee_putcharTO(x + dx, y + dy / 2, c);
37        ee_putcharTO(x - dx, y + dy / 2, c);
38        ee_putcharTO(x + dx, y - dy / 2, c);
39        ee_putcharTO(x - dx, y - dy / 2, c);
40
41        ee_putcharTO(x + dy, y + dx / 2, c);
42        ee_putcharTO(x - dy, y + dx / 2, c);
43        ee_putcharTO(x + dy, y - dx / 2, c);
44        ee_putcharTO(x - dy, y - dx / 2, c);
45
46        test += test > 0 ? dx - dy-- : dx;
47    }
48}
49
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