1 /* $Id$Revision: */
2 /* vim:set shiftwidth=4 ts=8: */
3
4 /*************************************************************************
5 * Copyright (c) 2011 AT&T Intellectual Property
6 * All rights reserved. This program and the accompanying materials
7 * are made available under the terms of the Eclipse Public License v1.0
8 * which accompanies this distribution, and is available at
9 * http://www.eclipse.org/legal/epl-v10.html
10 *
11 * Contributors: See CVS logs. Details at http://www.graphviz.org/
12 *************************************************************************/
13
14 #include "general.h"
15 #include "colorutil.h"
16
r2hex(float r,char * h)17 static void r2hex(float r, char *h){
18 /* convert a number in [0,1] to 0 to 255 then to a hex */
19 static char hex[] = "0123456789abcdef";
20 int i = (int)(255*r+0.5);
21 int j = i%16;
22 int k = i/16;
23 h[0] = hex[k];
24 h[1] = hex[j];
25 }
26
rgb2hex(float r,float g,float b,char * cstring,char * opacity)27 void rgb2hex(float r, float g, float b, char *cstring, char *opacity){
28 cstring[0] = '#';
29 r2hex(r, &(cstring[1]));
30 r2hex(g, &(cstring[3]));
31 r2hex(b, &(cstring[5]));
32 //set to semitransparent for multiple sets vis
33 if (opacity && strlen(opacity) >= 2){
34 cstring[7] = opacity[0];
35 cstring[8] = opacity[1];
36 cstring[9]='\0';
37 } else {
38 cstring[7] = '\0';
39 }
40 }
41
Hue2RGB(real v1,real v2,real H)42 static real Hue2RGB(real v1, real v2, real H) {
43 if(H < 0.0) H += 1.0;
44 if(H > 1.0) H -= 1.0;
45 if((6.0*H) < 1.0) return (v1 + (v2 - v1) * 6.0 * H);
46 if((2.0*H) < 1.0) return v2;
47 if((3.0*H) < 2.0) return (v1 + (v2 - v1) * ((2.0/3.0) - H) * 6.0);
48 return v1;
49 }
50
51 char *hex[16]={"0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f"};
52
hue2rgb(real hue,char * color)53 char * hue2rgb(real hue, char *color){
54 real v1, v2, lightness = .5, saturation = 1;
55 int red, blue, green;
56
57 if(lightness < 0.5)
58 v2 = lightness * (1.0 + saturation);
59 else
60 v2 = (lightness + saturation) - (saturation * lightness);
61
62 v1 = 2.0 * lightness - v2;
63
64 red = (int)(255.0 * Hue2RGB(v1, v2, hue + (1.0/3.0)) + 0.5);
65 green = (int)(255.0 * Hue2RGB(v1, v2, hue) + 0.5);
66 blue = (int)(255.0 * Hue2RGB(v1, v2, hue - (1.0/3.0)) + 0.5);
67 color[0] = '#';
68 sprintf(color+1,"%s",hex[red/16]);
69 sprintf(color+2,"%s",hex[red%16]);
70 sprintf(color+3,"%s",hex[green/16]);
71 sprintf(color+4,"%s",hex[green%16]);
72 sprintf(color+5,"%s",hex[blue/16]);
73 sprintf(color+6,"%s",hex[blue%16]);
74 color[7] = '\0';
75 return color;
76 }
77
78
hue2rgb_real(real hue,real * color)79 void hue2rgb_real(real hue, real *color){
80 real v1, v2, lightness = .5, saturation = 1;
81 int red, blue, green;
82
83 if(lightness < 0.5)
84 v2 = lightness * (1.0 + saturation);
85 else
86 v2 = (lightness + saturation) - (saturation * lightness);
87
88 v1 = 2.0 * lightness - v2;
89
90 red = (int)(255.0 * Hue2RGB(v1, v2, hue + (1.0/3.0)) + 0.5);
91 green = (int)(255.0 * Hue2RGB(v1, v2, hue) + 0.5);
92 blue = (int)(255.0 * Hue2RGB(v1, v2, hue - (1.0/3.0)) + 0.5);
93
94
95 color[0] = red/255.;
96 color[1] = green/255.;
97 color[2] = blue/255.;
98
99 }
100