1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
|
/* $Id$
*
* Copyright © 2005 Keith Packard
*
* This library is free software; you can redistribute it and/or
* modify it either under the terms of the GNU Lesser General Public
* License version 2.1 as published by the Free Software Foundation
* (the "LGPL") or, at your option, under the terms of the Mozilla
* Public License Version 1.1 (the "MPL"). If you do not alter this
* notice, a recipient may use your version of this file under either
* the MPL or the LGPL.
*
* You should have received a copy of the LGPL along with this library
* in the file COPYING-LGPL-2.1; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
* You should have received a copy of the MPL along with this library
* in the file COPYING-MPL-1.1
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
* OF ANY KIND, either express or implied. See the LGPL or the MPL for
* the specific language governing rights and limitations.
*
* The Original Code is the cairo graphics library.
*
* The Initial Developer of the Original Code is Keith Packard
*
* Contributor(s):
* Keith Packard <keithp@keithp.com>
*/
autoimport Cairo;
typedef struct {
real min, max, space;
} grid_t;
void grid (cairo_t cr, grid_t h, grid_t v)
{
for (real x = h.min; x <= h.max; x += h.space)
{
move_to (cr, x, v.min);
line_to (cr, x, v.max);
}
for (real y = v.min; y <= v.max; y += v.space)
{
move_to (cr, h.min, y);
line_to (cr, h.max, y);
}
stroke (cr);
}
void dots (cairo_t cr, grid_t h, grid_t v, real size)
{
for (real x = h.min; x <= h.max; x += h.space)
{
for (real y = v.min; y <= v.max; y += v.space)
{
move_to (cr, x - size, y);
line_to (cr, x + size, y);
move_to (cr, x, y - size);
line_to (cr, x, y + size);
}
}
stroke (cr);
}
void
grid_png (string filename, int width, int height, real major, real x_minor, y_minor)
{
cairo_t cr = new_image (width, height);
set_line_width (cr, 2);
grid (cr,
(grid_t) { min = 0, max = width, space = major },
(grid_t) { min = 0, max = height, space = major });
set_line_width (cr, 1);
dots (cr,
(grid_t) { min = 0.5 + x_minor//2, max = width + 0.5, space = x_minor },
(grid_t) { min = 0.5 + y_minor//2, max = height + 0.5, space = y_minor },
major / 20);
write_to_png (cr, filename);
destroy (cr);
}
grid_png ("grid.png", 1000, 1000, 90, 18, 30);
|
