1 /**
2 Colors.c
3 All sorts of operations on colors.
4
5 @author Tyron
6 */
7
8 static const RGBA_ALPHA = 0;
9 static const RGBA_RED = 1;
10 static const RGBA_GREEN = 2;
11 static const RGBA_BLUE = 3;
12
13 // documented in /docs/sdk/script/fn
HSL(int h,int s,int l)14 global func HSL(int h, int s, int l) { return HSL2RGB(RGB(h, s, l)); }
HSLa(int h,int s,int l,int a)15 global func HSLa(int h, int s, int l, int a) { return HSL2RGB(RGB(h, s, l)) ^ ~(a & 255) << 24; }
16
17 // documented in /docs/sdk/script/fn
RGB(int r,int g,int b)18 global func RGB(int r, int g, int b) { return (255 << 24) | (r & 255) << 16 | (g & 255) << 8 | (b & 255); }
RGBa(int r,int g,int b,int a)19 global func RGBa (int r, int g, int b, int a) { return (a & 255) << 24 | (r & 255) << 16 | (g & 255) << 8 | (b & 255); }
20
21 // documented in /docs/sdk/script/fn
GetRGBaValue(int val,int sel)22 global func GetRGBaValue(int val, int sel) { return val >> ((3 - sel) * 8) & 255; }
DoRGBaValue(int val,int chng,int sel)23 global func DoRGBaValue(int val, int chng, int sel) { return val + (chng << ((3 - sel) * 8)); }
24
25 // documented in /docs/sdk/script/fn
SetRGBaValue(int val,int newval,int sel)26 global func SetRGBaValue(int val, int newval, int sel)
27 {
28 // 'delete' old color
29 val = val & ~(255 << ((3 - sel) * 8));
30 // add new
31 return val | newval << ((3 - sel) * 8);
32 }
33
34 // documented in /docs/sdk/script/fn
SplitRGBaValue(int rgb)35 global func SplitRGBaValue(int rgb)
36 {
37 return {
38 R = GetRGBaValue(rgb, RGBA_RED),
39 G = GetRGBaValue(rgb, RGBA_GREEN),
40 B = GetRGBaValue(rgb, RGBA_BLUE),
41 Alpha = GetRGBaValue(rgb, RGBA_ALPHA)
42 };
43 }
44
45 // documented in /docs/sdk/script/fn
HSL2RGB(int hsl)46 global func HSL2RGB(int hsl)
47 {
48 var hue = GetRGBaValue(hsl, 1), sat = GetRGBaValue(hsl, 2), lightness = GetRGBaValue(hsl, 3);
49 var red, green, blue;
50 var var1, var2;
51
52 if (sat == 0)
53 {
54 red = green = blue = lightness;
55 }
56 else
57 {
58 if (lightness < 128)
59 var2 = lightness * (255 + sat) / 255;
60 else
61 var2 = lightness + sat - lightness * sat / 255;
62
63 var1 = 2 * lightness - var2;
64
65 red = Hue_2_RGB(var1, var2, hue + 85);
66 green = Hue_2_RGB(var1, var2, hue);
67 blue = Hue_2_RGB(var1, var2, hue - 85);
68 }
69
70 return RGB(red, green, blue);
71 }
72
Hue_2_RGB(int var1,int var2,int hue)73 global func Hue_2_RGB(int var1, int var2, int hue)
74 {
75 if (hue < 0)
76 hue += 255;
77 if (hue > 255)
78 hue -= 255;
79 if (6 * hue < 255)
80 return var1 + (var2 - var1) * 6 * hue / 255;
81 if (2 * hue < 255)
82 return var2;
83 if (3 * hue < 510)
84 return var1 + (var2 - var1) * ( 510 / 3 - hue ) * 6 / 255;
85 return var1;
86 }
87
88 // documented in /docs/sdk/script/fn
RGB2HSL(int rgb)89 global func RGB2HSL(int rgb)
90 {
91 var red = GetRGBaValue(rgb, RGBA_RED), green = GetRGBaValue(rgb, RGBA_GREEN), blue = GetRGBaValue(rgb, RGBA_BLUE);
92 var min_val = Min(red, Min(green, blue)), max_val = Max(red, Max(green, blue));
93 var diff_val = max_val - min_val;
94 var lightness = (max_val + min_val) / 2;
95 var hue, sat, diff_red, diff_green, diff_blue;
96
97 if (diff_val==0)
98 {
99 hue = 0;
100 sat = 0;
101 }
102 else
103 {
104 if (lightness < 128)
105 sat = 255 * diff_val / (max_val + min_val);
106 else
107 sat = 255 * diff_val / (510 - (max_val + min_val));
108
109 diff_red = ((255 * (max_val - red)) / 6 + (255 * diff_val) / 2) / diff_val;
110 diff_green = ((255 * (max_val - green)) / 6 + (255 * diff_val) / 2) / diff_val;
111 diff_blue = ((255 * (max_val - blue )) / 6 + (255 * diff_val) / 2) / diff_val;
112
113 if (red == max_val)
114 hue = diff_blue -diff_green;
115 else if (green == max_val)
116 hue = 255 / 3 + diff_red - diff_blue;
117 else if (blue == max_val)
118 hue = 510 / 3 + diff_green - diff_red;
119
120 if (hue < 0)
121 hue += 255;
122 if (hue > 255)
123 hue -= 255;
124 }
125
126 return RGB(hue, sat, lightness);
127 }
128