colour.c

   1 /* $OpenBSD$ */
   2
   3 /*
   4  * Copyright (c) 2008 Nicholas Marriott <nicm@users.sourceforge.net>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
  15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
  16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <sys/types.h>
  20
  21 #include <ctype.h>
  22 #include <math.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25
  26 #include "tmux.h"
  27
  28 /*
  29  * Colour to string conversion functions. Bit 8 of the colour means it is one
  30  * of the 256 colour palette.
  31  */
  32
  33 /* An RGB colour. */
  34 struct colour_rgb {
  35         u_char  r;
  36         u_char  g;
  37         u_char  b;
  38 };
  39
  40 /* 256 colour RGB table, generated on first use. */
  41 struct colour_rgb *colour_rgb_256;
  42
  43 void    colour_rgb_generate256(void);
  44 double  colour_rgb_distance(struct colour_rgb *, struct colour_rgb *);
  45 int     colour_rgb_find(struct colour_rgb *);
  46
  47 /* Generate 256 colour RGB table. */
  48 void
  49 colour_rgb_generate256(void)
  50 {
  51         struct colour_rgb       *rgb;
  52         u_int                    i, r, g, b;
  53
  54         /*
  55          * Allocate the table. The first 16 colours are often changed by users
  56          * and terminals so don't include them.
  57          */
  58         colour_rgb_256 = xcalloc(240, sizeof *colour_rgb_256);
  59
  60         /* Add the colours first. */
  61         r = g = b = 0;
  62         for (i = 240; i > 24; i--) {
  63                 rgb = &colour_rgb_256[240 - i];
  64
  65                 if (r != 0)
  66                         rgb->r = (r * 40) + 55;
  67                 if (g != 0)
  68                         rgb->g = (g * 40) + 55;
  69                 if (b != 0)
  70                         rgb->b = (b * 40) + 55;
  71
  72                 b++;
  73                 if (b > 5) {
  74                         b = 0;
  75                         g++;
  76                 }
  77                 if (g > 5) {
  78                         g = 0;
  79                         r++;
  80                 }
  81         }
  82
  83         /* Then add the greys. */
  84         for (i = 24; i > 0; i--) {
  85                 rgb = &colour_rgb_256[240 - i];
  86
  87                 rgb->r = 8 + (24 - i) * 10;
  88                 rgb->g = 8 + (24 - i) * 10;
  89                 rgb->b = 8 + (24 - i) * 10;
  90         }
  91 }
  92
  93 /* Get colour RGB distance. */
  94 double
  95 colour_rgb_distance(struct colour_rgb *rgb1, struct colour_rgb *rgb2)
  96 {
  97         int     r, g, b;
  98
  99         r = rgb1->r - rgb2->r;
 100         g = rgb1->g - rgb2->g;
 101         b = rgb1->b - rgb2->b;
 102         return (sqrt(r * r + g * g + b * b));
 103 }
 104
 105 /* Work out the nearest colour from the 256 colour set. */
 106 int
 107 colour_rgb_find(struct colour_rgb *rgb)
 108 {
 109         double  distance, lowest;
 110         u_int   colour, i;
 111
 112         if (colour_rgb_256 == NULL)
 113                 colour_rgb_generate256();
 114
 115         colour = 16;
 116         lowest = INFINITY;
 117         for (i = 0; i < 240; i++) {
 118                 distance = colour_rgb_distance(&colour_rgb_256[i], rgb);
 119                 if (distance < lowest) {
 120                         lowest = distance;
 121                         colour = 16 + i;
 122                 }
 123         }
 124         return (colour);
 125 }
 126
 127 /* Set grid cell foreground colour. */
 128 void
 129 colour_set_fg(struct grid_cell *gc, int c)
 130 {
 131         if (c & 0x100)
 132                 gc->flags |= GRID_FLAG_FG256;
 133         gc->fg = c;
 134 }
 135
 136 /* Set grid cell background colour. */
 137 void
 138 colour_set_bg(struct grid_cell *gc, int c)
 139 {
 140         if (c & 0x100)
 141                 gc->flags |= GRID_FLAG_BG256;
 142         gc->bg = c;
 143 }
 144
 145 /* Convert colour to a string. */
 146 const char *
 147 colour_tostring(int c)
 148 {
 149         static char     s[32];
 150
 151         if (c & 0x100) {
 152                 xsnprintf(s, sizeof s, "colour%u", c & ~0x100);
 153                 return (s);
 154         }
 155
 156         switch (c) {
 157         case 0:
 158                 return ("black");
 159         case 1:
 160                 return ("red");
 161         case 2:
 162                 return ("green");
 163         case 3:
 164                 return ("yellow");
 165         case 4:
 166                 return ("blue");
 167         case 5:
 168                 return ("magenta");
 169         case 6:
 170                 return ("cyan");
 171         case 7:
 172                 return ("white");
 173         case 8:
 174                 return ("default");
 175         }
 176         return (NULL);
 177 }
 178
 179 /* Convert colour from string. */
 180 int
 181 colour_fromstring(const char *s)
 182 {
 183         const char              *errstr;
 184         const char              *cp;
 185         struct colour_rgb        rgb;
 186         int                      n;
 187
 188         if (*s == '#' && strlen(s) == 7) {
 189                 for (cp = s + 1; isxdigit((u_char) *cp); cp++)
 190                         ;
 191                 if (*cp != '\0')
 192                         return (-1);
 193                 n = sscanf(s + 1, "%2hhx%2hhx%2hhx", &rgb.r, &rgb.g, &rgb.b);
 194                 if (n != 3)
 195                         return (-1);
 196                 return (colour_rgb_find(&rgb) | 0x100);
 197         }
 198
 199         if (strncasecmp(s, "colour", (sizeof "colour") - 1) == 0) {
 200                 n = strtonum(s + (sizeof "colour") - 1, 0, 255, &errstr);
 201                 if (errstr != NULL)
 202                         return (-1);
 203                 return (n | 0x100);
 204         }
 205
 206         if (strcasecmp(s, "black") == 0 || (s[0] == '0' && s[1] == '\0'))
 207                 return (0);
 208         if (strcasecmp(s, "red") == 0 || (s[0] == '1' && s[1] == '\0'))
 209                 return (1);
 210         if (strcasecmp(s, "green") == 0 || (s[0] == '2' && s[1] == '\0'))
 211                 return (2);
 212         if (strcasecmp(s, "yellow") == 0 || (s[0] == '3' && s[1] == '\0'))
 213                 return (3);
 214         if (strcasecmp(s, "blue") == 0 || (s[0] == '4' && s[1] == '\0'))
 215                 return (4);
 216         if (strcasecmp(s, "magenta") == 0 || (s[0] == '5' && s[1] == '\0'))
 217                 return (5);
 218         if (strcasecmp(s, "cyan") == 0 || (s[0] == '6' && s[1] == '\0'))
 219                 return (6);
 220         if (strcasecmp(s, "white") == 0 || (s[0] == '7' && s[1] == '\0'))
 221                 return (7);
 222         if (strcasecmp(s, "default") == 0 || (s[0] == '8' && s[1] == '\0'))
 223                 return (8);
 224         return (-1);
 225 }
 226
 227 /* Convert 256 colour palette to 16. */
 228 u_char
 229 colour_256to16(u_char c)
 230 {
 231         static const u_char table[256] = {
 232                  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
 233                  0,  4,  4,  4, 12, 12,  2,  6,  4,  4, 12, 12,  2,  2,  6,  4,
 234                 12, 12,  2,  2,  2,  6, 12, 12, 10, 10, 10, 10, 14, 12, 10, 10,
 235                 10, 10, 10, 14,  1,  5,  4,  4, 12, 12,  3,  8,  4,  4, 12, 12,
 236                  2,  2,  6,  4, 12, 12,  2,  2,  2,  6, 12, 12, 10, 10, 10, 10,
 237                 14, 12, 10, 10, 10, 10, 10, 14,  1,  1,  5,  4, 12, 12,  1,  1,
 238                  5,  4, 12, 12,  3,  3,  8,  4, 12, 12,  2,  2,  2,  6, 12, 12,
 239                 10, 10, 10, 10, 14, 12, 10, 10, 10, 10, 10, 14,  1,  1,  1,  5,
 240                 12, 12,  1,  1,  1,  5, 12, 12,  1,  1,  1,  5, 12, 12,  3,  3,
 241                  3,  7, 12, 12, 10, 10, 10, 10, 14, 12, 10, 10, 10, 10, 10, 14,
 242                  9,  9,  9,  9, 13, 12,  9,  9,  9,  9, 13, 12,  9,  9,  9,  9,
 243                 13, 12,  9,  9,  9,  9, 13, 12, 11, 11, 11, 11,  7, 12, 10, 10,
 244                 10, 10, 10, 14,  9,  9,  9,  9,  9, 13,  9,  9,  9,  9,  9, 13,
 245                  9,  9,  9,  9,  9, 13,  9,  9,  9,  9,  9, 13,  9,  9,  9,  9,
 246                  9, 13, 11, 11, 11, 11, 11, 15,  0,  0,  0,  0,  0,  0,  8,  8,
 247                  8,  8,  8,  8,  7,  7,  7,  7,  7,  7, 15, 15, 15, 15, 15, 15
 248         };
 249
 250         return (table[c]);
 251 }
 252
 253 /* Convert 256 colour palette to 88. */
 254 u_char
 255 colour_256to88(u_char c)
 256 {
 257         static const u_char table[256] = {
 258                  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
 259                 16, 17, 17, 18, 18, 19, 20, 21, 21, 22, 22, 23, 20, 21, 21, 22,
 260                 22, 23, 24, 25, 25, 26, 26, 27, 24, 25, 25, 26, 26, 27, 28, 29,
 261                 29, 30, 30, 31, 32, 33, 33, 34, 34, 35, 36, 37, 37, 38, 38, 39,
 262                 36, 37, 37, 38, 38, 39, 40, 41, 41, 42, 42, 43, 40, 41, 41, 42,
 263                 42, 43, 44, 45, 45, 46, 46, 47, 32, 33, 33, 34, 34, 35, 36, 37,
 264                 37, 38, 38, 39, 36, 37, 37, 38, 38, 39, 40, 41, 41, 42, 42, 43,
 265                 40, 41, 41, 42, 42, 43, 44, 45, 45, 46, 46, 47, 48, 49, 49, 50,
 266                 50, 51, 52, 53, 53, 54, 54, 55, 52, 53, 53, 54, 54, 55, 56, 57,
 267                 57, 58, 58, 59, 56, 57, 57, 58, 58, 59, 60, 61, 61, 62, 62, 63,
 268                 48, 49, 49, 50, 50, 51, 52, 53, 53, 54, 54, 55, 52, 53, 53, 54,
 269                 54, 55, 56, 57, 57, 58, 58, 59, 56, 57, 57, 58, 58, 59, 60, 61,
 270                 61, 62, 62, 63, 64, 65, 65, 66, 66, 67, 68, 69, 69, 70, 70, 71,
 271                 68, 69, 69, 70, 70, 71, 72, 73, 73, 74, 74, 75, 72, 73, 73, 74,
 272                 74, 75, 76, 77, 77, 78, 78, 79,  0,  0, 80, 80, 80, 81, 81, 81,
 273                 82, 82, 82, 83, 83, 83, 84, 84, 84, 85, 85, 85, 86, 86, 86, 87
 274         };
 275
 276         return (table[c]);
 277 }