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         case 90:
 174                 return ("brightblack");
 175         case 91:
 176                 return ("brightred");
 177         case 92:
 178                 return ("brightgreen");
 179         case 93:
 180                 return ("brightyellow");
 181         case 94:
 182                 return ("brightblue");
 183         case 95:
 184                 return ("brightmagenta");
 185         case 96:
 186                 return ("brightcyan");
 187         case 97:
 188                 return ("brightwhite");
 189         }
 190         return (NULL);
 191 }
 192
 193 /* Convert colour from string. */
 194 int
 195 colour_fromstring(const char *s)
 196 {
 197         const char              *errstr;
 198         const char              *cp;
 199         struct colour_rgb        rgb;
 200         int                      n;
 201
 202         if (*s == '#' && strlen(s) == 7) {
 203                 for (cp = s + 1; isxdigit((u_char) *cp); cp++)
 204                         ;
 205                 if (*cp != '\0')
 206                         return (-1);
 207                 n = sscanf(s + 1, "%2hhx%2hhx%2hhx", &rgb.r, &rgb.g, &rgb.b);
 208                 if (n != 3)
 209                         return (-1);
 210                 return (colour_rgb_find(&rgb) | 0x100);
 211         }
 212
 213         if (strncasecmp(s, "colour", (sizeof "colour") - 1) == 0) {
 214                 n = strtonum(s + (sizeof "colour") - 1, 0, 255, &errstr);
 215                 if (errstr != NULL)
 216                         return (-1);
 217                 return (n | 0x100);
 218         }
 219
 220         if (strcasecmp(s, "black") == 0 || (s[0] == '0' && s[1] == '\0'))
 221                 return (0);
 222         if (strcasecmp(s, "red") == 0 || (s[0] == '1' && s[1] == '\0'))
 223                 return (1);
 224         if (strcasecmp(s, "green") == 0 || (s[0] == '2' && s[1] == '\0'))
 225                 return (2);
 226         if (strcasecmp(s, "yellow") == 0 || (s[0] == '3' && s[1] == '\0'))
 227                 return (3);
 228         if (strcasecmp(s, "blue") == 0 || (s[0] == '4' && s[1] == '\0'))
 229                 return (4);
 230         if (strcasecmp(s, "magenta") == 0 || (s[0] == '5' && s[1] == '\0'))
 231                 return (5);
 232         if (strcasecmp(s, "cyan") == 0 || (s[0] == '6' && s[1] == '\0'))
 233                 return (6);
 234         if (strcasecmp(s, "white") == 0 || (s[0] == '7' && s[1] == '\0'))
 235                 return (7);
 236         if (strcasecmp(s, "default") == 0 || (s[0] == '8' && s[1] == '\0'))
 237                 return (8);
 238         if (strcasecmp(s, "brightblack") == 0 ||
 239             (s[0] == '9' && s[1] == '0' && s[1] == '\0'))
 240                 return (90);
 241         if (strcasecmp(s, "brightred") == 0 ||
 242             (s[0] == '9' && s[1] == '1' && s[1] == '\0'))
 243                 return (91);
 244         if (strcasecmp(s, "brightgreen") == 0 ||
 245             (s[0] == '9' && s[1] == '2' && s[1] == '\0'))
 246                 return (92);
 247         if (strcasecmp(s, "brightyellow") == 0 ||
 248             (s[0] == '9' && s[1] == '3' && s[1] == '\0'))
 249                 return (93);
 250         if (strcasecmp(s, "brightblue") == 0 ||
 251             (s[0] == '9' && s[1] == '4' && s[1] == '\0'))
 252                 return (94);
 253         if (strcasecmp(s, "brightmagenta") == 0 ||
 254             (s[0] == '9' && s[1] == '5' && s[1] == '\0'))
 255                 return (95);
 256         if (strcasecmp(s, "brightcyan") == 0 ||
 257             (s[0] == '9' && s[1] == '6' && s[1] == '\0'))
 258                 return (96);
 259         if (strcasecmp(s, "brightwhite") == 0 ||
 260             (s[0] == '9' && s[1] == '7' && s[1] == '\0'))
 261                 return (97);
 262         return (-1);
 263 }
 264
 265 /* Convert 256 colour palette to 16. */
 266 u_char
 267 colour_256to16(u_char c)
 268 {
 269         static const u_char table[256] = {
 270                  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
 271                  0,  4,  4,  4, 12, 12,  2,  6,  4,  4, 12, 12,  2,  2,  6,  4,
 272                 12, 12,  2,  2,  2,  6, 12, 12, 10, 10, 10, 10, 14, 12, 10, 10,
 273                 10, 10, 10, 14,  1,  5,  4,  4, 12, 12,  3,  8,  4,  4, 12, 12,
 274                  2,  2,  6,  4, 12, 12,  2,  2,  2,  6, 12, 12, 10, 10, 10, 10,
 275                 14, 12, 10, 10, 10, 10, 10, 14,  1,  1,  5,  4, 12, 12,  1,  1,
 276                  5,  4, 12, 12,  3,  3,  8,  4, 12, 12,  2,  2,  2,  6, 12, 12,
 277                 10, 10, 10, 10, 14, 12, 10, 10, 10, 10, 10, 14,  1,  1,  1,  5,
 278                 12, 12,  1,  1,  1,  5, 12, 12,  1,  1,  1,  5, 12, 12,  3,  3,
 279                  3,  7, 12, 12, 10, 10, 10, 10, 14, 12, 10, 10, 10, 10, 10, 14,
 280                  9,  9,  9,  9, 13, 12,  9,  9,  9,  9, 13, 12,  9,  9,  9,  9,
 281                 13, 12,  9,  9,  9,  9, 13, 12, 11, 11, 11, 11,  7, 12, 10, 10,
 282                 10, 10, 10, 14,  9,  9,  9,  9,  9, 13,  9,  9,  9,  9,  9, 13,
 283                  9,  9,  9,  9,  9, 13,  9,  9,  9,  9,  9, 13,  9,  9,  9,  9,
 284                  9, 13, 11, 11, 11, 11, 11, 15,  0,  0,  0,  0,  0,  0,  8,  8,
 285                  8,  8,  8,  8,  7,  7,  7,  7,  7,  7, 15, 15, 15, 15, 15, 15
 286         };
 287
 288         return (table[c]);
 289 }