source: ttyvaders/trunk/libee/triangle.c @ 160

Last change on this file since 160 was 160, checked in by Sam Hocevar, 16 years ago
  • libee/ee.h: + Added ee_color_names[] containing our 16 color names.
  • libee/ee.c: + Extended our color set to the full 16 instead of 10. + Precalculate ncurses attributes.
  • libee/graphics.c: + Clip color value in ee_set_color(). + Clip characters in ee_putchar(). + Partially clip characters in ee_putstr(), overflows aren't checked yet.
  • libee/ee_internals.h: + New file to share extern variables within libee.
  • test/demo.c: + Added a simple demo_color() to output all colors. + Replaced four ee_draw_line() with ee_draw_thin_box(). + Replaced x1, y1, x2 etc. with xa, ya, xb etc. because <math.h> already

defines y1.

+ Randomized colours from 0 to 15 instead of 1 to 10.

  • src/Makefiles.am: + Added -lm to the ttyvaders linking flags because of the intro.
  • README BUGS TODO: + Updated.
  • Property svn:keywords set to Id
File size: 2.6 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: triangle.c 160 2003-11-12 21:18:50Z 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#include "ee_internals.h"
29
30void ee_draw_triangle(int x1, int y1, int x2, int y2, int x3, int y3, char c)
31{
32    ee_draw_line(x1, y1, x2, y2, c);
33    ee_draw_line(x2, y2, x3, y3, c);
34    ee_draw_line(x3, y3, x1, y1, c);
35}
36
37void ee_draw_thin_triangle(int x1, int y1, int x2, int y2, int x3, int y3)
38{
39    ee_draw_thin_line(x1, y1, x2, y2);
40    ee_draw_thin_line(x2, y2, x3, y3);
41    ee_draw_thin_line(x3, y3, x1, y1);
42}
43
44void ee_fill_triangle(int x1, int y1, int x2, int y2, int x3, int y3, char c)
45{
46    int x, y, xa, xb, xmax, ymax;
47
48    /* Bubble-sort y1 <= y2 <= y3 */
49    if(y1 > y2)
50    {
51        ee_fill_triangle(x2, y2, x1, y1, x3, y3, c);
52        return;
53    }
54
55    if(y2 > y3)
56    {
57        ee_fill_triangle(x1, y1, x3, y3, x2, y2, c);
58        return;
59    }
60
61    /* Promote precision */
62    x1 *= 4;
63    x2 *= 4;
64    x3 *= 4;
65
66    xmax = ee_get_width() - 1;
67    ymax = ee_get_height() - 1;
68
69    /* Rasterize our triangle */
70    for(y = y1 < 0 ? 0 : y1; y <= y3 && y <= ymax; y++)
71    {
72        if(y <= y2)
73        {
74            xa = (y1 == y2) ? x2 : x1 + (x2 - x1) * (y - y1) / (y2 - y1);
75            xb = (y1 == y3) ? x3 : x1 + (x3 - x1) * (y - y1) / (y3 - y1);
76        }
77        else
78        {
79            xa = (y3 == y2) ? x2 : x3 + (x2 - x3) * (y - y3) / (y2 - y3);
80            xb = (y3 == y1) ? x1 : x3 + (x1 - x3) * (y - y3) / (y1 - y3);
81        }
82
83        if(xb < xa)
84        {
85            int tmp = xb;
86            xb = xa; xa = tmp;
87        }
88
89        /* Rescale xa and xb, slightly cropping */
90        xa = (xa + 2) / 4;
91        xb = (xb - 2) / 4;
92
93        if(xb < 0) continue;
94        if(xa > xmax) continue;
95        if(xa < 0) xa = 0;
96        if(xb > xmax) xb = xmax;
97
98        for(x = xa; x <= xb; x++)
99            ee_putchar(x, y, c);
100    }
101}
102
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