1 /*!
2 \file lib/display/icon.c
3
4 \brief Display Library - Plot icon
5
6 (C) 2001-2008, 2012 by the GRASS Development Team
7
8 This program is free software under the GNU General Public License
9 (>=v2). Read the file COPYING that comes with GRASS for details.
10
11 \author USA-CERL
12 */
13
14 #include <stdlib.h>
15 #include <math.h>
16 #include <grass/gis.h>
17 #include <grass/display.h>
18 #include <grass/glocale.h>
19
line(double m[2][3],double x0,double y0,double x1,double y1)20 static void line(double m[2][3], double x0, double y0, double x1, double y1)
21 {
22 double tx0 = m[0][0] * x0 + m[0][1] * y0 + m[0][2];
23 double ty0 = m[1][0] * x0 + m[1][1] * y0 + m[1][2];
24 double tx1 = m[0][0] * x1 + m[0][1] * y1 + m[0][2];
25 double ty1 = m[1][0] * x1 + m[1][1] * y1 + m[1][2];
26
27 D_line_abs(tx0, ty0, tx1, ty1);
28 }
29
30 /*!
31 \brief Plot icon
32
33 Supported types:
34 - G_ICON_CROSS
35 - G_ICON_BOX
36 - G_ICON_ARROW
37
38 \param xc,yc icon coordinates
39 \param type icon type
40 \param angle rotation angle [rad]
41 \param scale scale factor
42 */
D_plot_icon(double xc,double yc,int type,double angle,double scale)43 void D_plot_icon(double xc, double yc, int type, double angle, double scale)
44 {
45 static double old_a = 1e299, old_s = 0;
46 static double sin_a, cos_a;
47 static double m[2][3];
48
49 G_debug(2, "D_plot_icon(): xc=%g, yc=%g", xc, yc);
50
51 if (angle != old_a) {
52 sin_a = sin(angle);
53 cos_a = cos(angle);
54 }
55 if (angle != old_a || scale != old_s) {
56 m[0][0] = cos_a * scale;
57 m[0][1] = -sin_a * scale;
58 m[1][0] = sin_a * scale;
59 m[1][1] = cos_a * scale;
60 }
61 m[0][2] = xc;
62 m[1][2] = yc;
63
64 switch (type) {
65 case G_ICON_CROSS:
66 line(m, -0.5, 0.0, 0.5, 0.0);
67 line(m, 0.0, -0.5, 0.0, 0.5);
68 break;
69 case G_ICON_BOX:
70 line(m, -0.5, -0.5, 0.5, -0.5);
71 line(m, 0.5, -0.5, 0.5, 0.5);
72 line(m, 0.5, 0.5, -0.5, 0.5);
73 line(m, -0.5, 0.5, -0.5, -0.5);
74 break;
75 case G_ICON_ARROW:
76 line(m, -1, 0.5, 0, 0.0);
77 line(m, -1, -0.5, 0, 0.0);
78 break;
79 default:
80 G_warning(_("Unsupported icon %d"), type);
81 break;
82 }
83 }
84