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 <stdlib.h>
  23 #include <string.h>
  24
  25 #include "tmux.h"
  26
  27 /*
  28  * Colour to string conversion functions. Bit 8 of the colour means it is one
  29  * of the 256 colour palette.
  30  */
  31
  32 /* An RGB colour. */
  33 struct colour_rgb {
  34         u_char  r;
  35         u_char  g;
  36         u_char  b;
  37 };
  38
  39 /* 256 colour RGB table, generated on first use. */
  40 struct colour_rgb *colour_rgb_256;
  41
  42 void    colour_rgb_generate256(void);
  43 u_int   colour_rgb_distance(struct colour_rgb *, struct colour_rgb *);
  44 int     colour_rgb_find(struct colour_rgb *);
  45
  46 /* Generate 256 colour RGB table. */
  47 void
  48 colour_rgb_generate256(void)
  49 {
  50         struct colour_rgb       *rgb;
  51         u_int                    i, r, g, b;
  52
  53         /*
  54          * Allocate the table. The first 16 colours are often changed by users
  55          * and terminals so don't include them.
  56          */
  57         colour_rgb_256 = xcalloc(240, sizeof *colour_rgb_256);
  58
  59         /* Add the colours first. */
  60         r = g = b = 0;
  61         for (i = 240; i > 24; i--) {
  62                 rgb = &colour_rgb_256[240 - i];
  63
  64                 if (r != 0)
  65                         rgb->r = (r * 40) + 55;
  66                 if (g != 0)
  67                         rgb->g = (g * 40) + 55;
  68                 if (b != 0)
  69                         rgb->b = (b * 40) + 55;
  70
  71                 b++;
  72                 if (b > 5) {
  73                         b = 0;
  74                         g++;
  75                 }
  76                 if (g > 5) {
  77                         g = 0;
  78                         r++;
  79                 }
  80         }
  81
  82         /* Then add the greys. */
  83         for (i = 24; i > 0; i--) {
  84                 rgb = &colour_rgb_256[240 - i];
  85
  86                 rgb->r = 8 + (24 - i) * 10;
  87                 rgb->g = 8 + (24 - i) * 10;
  88                 rgb->b = 8 + (24 - i) * 10;
  89         }
  90 }
  91
  92 /* Get colour RGB distance. */
  93 u_int
  94 colour_rgb_distance(struct colour_rgb *rgb1, struct colour_rgb *rgb2)
  95 {
  96         int     r, g, b;
  97
  98         r = rgb1->r - rgb2->r;
  99         g = rgb1->g - rgb2->g;
 100         b = rgb1->b - rgb2->b;
 101         return (r * r + g * g + b * b);
 102 }
 103
 104 /* Work out the nearest colour from the 256 colour set. */
 105 int
 106 colour_rgb_find(struct colour_rgb *rgb)
 107 {
 108         u_int   distance, lowest, colour, i;
 109
 110         if (colour_rgb_256 == NULL)
 111                 colour_rgb_generate256();
 112
 113         colour = 16;
 114         lowest = UINT_MAX;
 115         for (i = 0; i < 240; i++) {
 116                 distance = colour_rgb_distance(&colour_rgb_256[i], rgb);
 117                 if (distance < lowest) {
 118                         lowest = distance;
 119                         colour = 16 + i;
 120                 }
 121         }
 122         return (colour);
 123 }
 124
 125 /* Set grid cell foreground colour. */
 126 void
 127 colour_set_fg(struct grid_cell *gc, int c)
 128 {
 129         if (c & 0x100)
 130                 gc->flags |= GRID_FLAG_FG256;
 131         gc->fg = c;
 132 }
 133
 134 /* Set grid cell background colour. */
 135 void
 136 colour_set_bg(struct grid_cell *gc, int c)
 137 {
 138         if (c & 0x100)
 139                 gc->flags |= GRID_FLAG_BG256;
 140         gc->bg = c;
 141 }
 142
 143 /* Convert colour to a string. */
 144 const char *
 145 colour_tostring(int c)
 146 {
 147         static char     s[32];
 148
 149         if (c & 0x100) {
 150                 xsnprintf(s, sizeof s, "colour%u", c & ~0x100);
 151                 return (s);
 152         }
 153
 154         switch (c) {
 155         case 0:
 156                 return ("black");
 157         case 1:
 158                 return ("red");
 159         case 2:
 160                 return ("green");
 161         case 3:
 162                 return ("yellow");
 163         case 4:
 164                 return ("blue");
 165         case 5:
 166                 return ("magenta");
 167         case 6:
 168                 return ("cyan");
 169         case 7:
 170                 return ("white");
 171         case 8:
 172                 return ("default");
 173         }
 174         return (NULL);
 175 }
 176
 177 /* Convert colour from string. */
 178 int
 179 colour_fromstring(const char *s)
 180 {
 181         const char              *errstr;
 182         const char              *cp;
 183         struct colour_rgb        rgb;
 184         int                      n;
 185
 186         if (*s == '#' && strlen(s) == 7) {
 187                 for (cp = s + 1; isxdigit((u_char) *cp); cp++)
 188                         ;
 189                 if (*cp != '\0')
 190                         return (-1);
 191                 n = sscanf(s + 1, "%2hhx%2hhx%2hhx", &rgb.r, &rgb.g, &rgb.b);
 192                 if (n != 3)
 193                         return (-1);
 194                 return (colour_rgb_find(&rgb) | 0x100);
 195         }
 196
 197         if (strncasecmp(s, "colour", (sizeof "colour") - 1) == 0) {
 198                 n = strtonum(s + (sizeof "colour") - 1, 0, 255, &errstr);
 199                 if (errstr != NULL)
 200                         return (-1);
 201                 return (n | 0x100);
 202         }
 203
 204         if (strcasecmp(s, "black") == 0 || (s[0] == '0' && s[1] == '\0'))
 205                 return (0);
 206         if (strcasecmp(s, "red") == 0 || (s[0] == '1' && s[1] == '\0'))
 207                 return (1);
 208         if (strcasecmp(s, "green") == 0 || (s[0] == '2' && s[1] == '\0'))
 209                 return (2);
 210         if (strcasecmp(s, "yellow") == 0 || (s[0] == '3' && s[1] == '\0'))
 211                 return (3);
 212         if (strcasecmp(s, "blue") == 0 || (s[0] == '4' && s[1] == '\0'))
 213                 return (4);
 214         if (strcasecmp(s, "magenta") == 0 || (s[0] == '5' && s[1] == '\0'))
 215                 return (5);
 216         if (strcasecmp(s, "cyan") == 0 || (s[0] == '6' && s[1] == '\0'))
 217                 return (6);
 218         if (strcasecmp(s, "white") == 0 || (s[0] == '7' && s[1] == '\0'))
 219                 return (7);
 220         if (strcasecmp(s, "default") == 0 || (s[0] == '8' && s[1] == '\0'))
 221                 return (8);
 222         return (-1);
 223 }
 224
 225 /* Convert 256 colour palette to 16. */
 226 u_char
 227 colour_256to16(u_char c)
 228 {
 229         static const u_char table[256] = {
 230                  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
 231                  0,  4,  4,  4, 12, 12,  2,  6,  4,  4, 12, 12,  2,  2,  6,  4,
 232                 12, 12,  2,  2,  2,  6, 12, 12, 10, 10, 10, 10, 14, 12, 10, 10,
 233                 10, 10, 10, 14,  1,  5,  4,  4, 12, 12,  3,  8,  4,  4, 12, 12,
 234                  2,  2,  6,  4, 12, 12,  2,  2,  2,  6, 12, 12, 10, 10, 10, 10,
 235                 14, 12, 10, 10, 10, 10, 10, 14,  1,  1,  5,  4, 12, 12,  1,  1,
 236                  5,  4, 12, 12,  3,  3,  8,  4, 12, 12,  2,  2,  2,  6, 12, 12,
 237                 10, 10, 10, 10, 14, 12, 10, 10, 10, 10, 10, 14,  1,  1,  1,  5,
 238                 12, 12,  1,  1,  1,  5, 12, 12,  1,  1,  1,  5, 12, 12,  3,  3,
 239                  3,  7, 12, 12, 10, 10, 10, 10, 14, 12, 10, 10, 10, 10, 10, 14,
 240                  9,  9,  9,  9, 13, 12,  9,  9,  9,  9, 13, 12,  9,  9,  9,  9,
 241                 13, 12,  9,  9,  9,  9, 13, 12, 11, 11, 11, 11,  7, 12, 10, 10,
 242                 10, 10, 10, 14,  9,  9,  9,  9,  9, 13,  9,  9,  9,  9,  9, 13,
 243                  9,  9,  9,  9,  9, 13,  9,  9,  9,  9,  9, 13,  9,  9,  9,  9,
 244                  9, 13, 11, 11, 11, 11, 11, 15,  0,  0,  0,  0,  0,  0,  8,  8,
 245                  8,  8,  8,  8,  7,  7,  7,  7,  7,  7, 15, 15, 15, 15, 15, 15
 246         };
 247
 248         return (table[c]);
 249 }
 250
 251 /* Convert 256 colour palette to 88. */
 252 u_char
 253 colour_256to88(u_char c)
 254 {
 255         static const u_char table[256] = {
 256                  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
 257                 16, 17, 17, 18, 18, 19, 20, 21, 21, 22, 22, 23, 20, 21, 21, 22,
 258                 22, 23, 24, 25, 25, 26, 26, 27, 24, 25, 25, 26, 26, 27, 28, 29,
 259                 29, 30, 30, 31, 32, 33, 33, 34, 34, 35, 36, 37, 37, 38, 38, 39,
 260                 36, 37, 37, 38, 38, 39, 40, 41, 41, 42, 42, 43, 40, 41, 41, 42,
 261                 42, 43, 44, 45, 45, 46, 46, 47, 32, 33, 33, 34, 34, 35, 36, 37,
 262                 37, 38, 38, 39, 36, 37, 37, 38, 38, 39, 40, 41, 41, 42, 42, 43,
 263                 40, 41, 41, 42, 42, 43, 44, 45, 45, 46, 46, 47, 48, 49, 49, 50,
 264                 50, 51, 52, 53, 53, 54, 54, 55, 52, 53, 53, 54, 54, 55, 56, 57,
 265                 57, 58, 58, 59, 56, 57, 57, 58, 58, 59, 60, 61, 61, 62, 62, 63,
 266                 48, 49, 49, 50, 50, 51, 52, 53, 53, 54, 54, 55, 52, 53, 53, 54,
 267                 54, 55, 56, 57, 57, 58, 58, 59, 56, 57, 57, 58, 58, 59, 60, 61,
 268                 61, 62, 62, 63, 64, 65, 65, 66, 66, 67, 68, 69, 69, 70, 70, 71,
 269                 68, 69, 69, 70, 70, 71, 72, 73, 73, 74, 74, 75, 72, 73, 73, 74,
 270                 74, 75, 76, 77, 77, 78, 78, 79,  0,  0, 80, 80, 80, 81, 81, 81,
 271                 82, 82, 82, 83, 83, 83, 84, 84, 84, 85, 85, 85, 86, 86, 86, 87
 272         };
 273
 274         return (table[c]);
 275 }