| Geant4 Cross Reference |
1 // Copyright (C) 2010, Guy Barrand. All rights
2 // See the file tools.license for terms.
3
4 #ifndef tools_hls
5 #define tools_hls
6
7 namespace tools {
8
9 //T is float or double.
10
11 template <class T>
12 inline T hls_to_rgb2(T rn1,T rn2,T huei) {
13 // taken from CERN-ROOT/TColor.
14 T hue = huei;
15 if (hue > 360) hue = hue - 360;
16 if (hue < 0) hue = hue + 360;
17 if (hue < 60 ) return rn1 + (rn2-rn1)*hue/60
18 if (hue < 180) return rn2;
19 if (hue < 240) return rn1 + (rn2-rn1)*(240-h
20 return rn1;
21 }
22
23 template <class T>
24 inline void hls_to_rgb(T hue,T light,T satur,T
25 // taken from CERN-ROOT/TColor.
26 // Static method to compute RGB from HLS. Th
27 // and h is between [0,360]. The returned r,
28
29 T rh, rl, rs, rm1, rm2;
30 rh = rl = rs = 0;
31
32 if (hue > 0) rh = hue;
33 if (rh > 360) rh = 360;
34
35 if (light > 0) rl = light;
36 if (rl > 1) rl = 1;
37
38 if (satur > 0) rs = satur;
39 if (rs > 1) rs = 1;
40
41 if (rl <= T(0.5)) {
42 rm2 = rl*(1 + rs);
43 } else {
44 rm2 = rl + rs - rl*rs;
45 }
46 rm1 = 2*rl - rm2;
47
48 if (!rs) { a_r = rl; a_g = rl; a_b = rl; ret
49 a_r = hls_to_rgb2(rm1, rm2, rh+120);
50 a_g = hls_to_rgb2(rm1, rm2, rh);
51 a_b = hls_to_rgb2(rm1, rm2, rh-120);
52 }
53
54 template <class T>
55 inline void rgb_to_hls(T rr,T gg,T bb,T& hue,T
56 // The r,g,b triplet is between
57 // [0,1], hue is between [0,360], light and
58
59 T rnorm, gnorm, bnorm, minval, maxval, msum,
60 minval = maxval = 0;
61 cr = cg = cb = 0;
62
63 if (rr > 0) cr = rr;
64 if (cr > 1) cr = 1;
65
66 if (gg > 0) cg = gg;
67 if (cg > 1) cg = 1;
68
69 if (bb > 0) cb = bb;
70 if (cb > 1) cb = 1;
71
72 minval = cr;
73 if (cg < minval) minval = cg;
74 if (cb < minval) minval = cb;
75 maxval = cr;
76 if (cg > maxval) maxval = cg;
77 if (cb > maxval) maxval = cb;
78
79 rnorm = gnorm = bnorm = 0;
80 mdiff = maxval - minval;
81 msum = maxval + minval;
82 light = T(0.5) * msum;
83 if (maxval != minval) {
84 rnorm = (maxval - cr)/mdiff;
85 gnorm = (maxval - cg)/mdiff;
86 bnorm = (maxval - cb)/mdiff;
87 } else {
88 satur = hue = 0;
89 return;
90 }
91
92 if (light < T(0.5))
93 satur = mdiff/msum;
94 else
95 satur = mdiff/(2 - msum);
96
97 if (cr == maxval)
98 hue = 60 * (6 + bnorm - gnorm);
99 else if (cg == maxval)
100 hue = 60 * (2 + rnorm - bnorm);
101 else
102 hue = 60 * (4 + gnorm - rnorm);
103
104 if (hue > 360)
105 hue = hue - 360;
106 }
107
108
109 }
110
111 #endif