Annotation of embedaddon/tmux/colour.c, revision 1.1.1.1

1.1       misho       1: /* $OpenBSD$ */
                      2: 
                      3: /*
                      4:  * Copyright (c) 2008 Nicholas Marriott <nicholas.marriott@gmail.com>
                      5:  * Copyright (c) 2016 Avi Halachmi <avihpit@yahoo.com>
                      6:  *
                      7:  * Permission to use, copy, modify, and distribute this software for any
                      8:  * purpose with or without fee is hereby granted, provided that the above
                      9:  * copyright notice and this permission notice appear in all copies.
                     10:  *
                     11:  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
                     12:  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
                     13:  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
                     14:  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
                     15:  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
                     16:  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
                     17:  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
                     18:  */
                     19: 
                     20: #include <sys/types.h>
                     21: 
                     22: #include <ctype.h>
                     23: #include <stdlib.h>
                     24: #include <string.h>
                     25: 
                     26: #include "tmux.h"
                     27: 
                     28: static int
                     29: colour_dist_sq(int R, int G, int B, int r, int g, int b)
                     30: {
                     31:        return ((R - r) * (R - r) + (G - g) * (G - g) + (B - b) * (B - b));
                     32: }
                     33: 
                     34: static int
                     35: colour_to_6cube(int v)
                     36: {
                     37:        if (v < 48)
                     38:                return (0);
                     39:        if (v < 114)
                     40:                return (1);
                     41:        return ((v - 35) / 40);
                     42: }
                     43: 
                     44: /*
                     45:  * Convert an RGB triplet to the xterm(1) 256 colour palette.
                     46:  *
                     47:  * xterm provides a 6x6x6 colour cube (16 - 231) and 24 greys (232 - 255). We
                     48:  * map our RGB colour to the closest in the cube, also work out the closest
                     49:  * grey, and use the nearest of the two.
                     50:  *
                     51:  * Note that the xterm has much lower resolution for darker colours (they are
                     52:  * not evenly spread out), so our 6 levels are not evenly spread: 0x0, 0x5f
                     53:  * (95), 0x87 (135), 0xaf (175), 0xd7 (215) and 0xff (255). Greys are more
                     54:  * evenly spread (8, 18, 28 ... 238).
                     55:  */
                     56: int
                     57: colour_find_rgb(u_char r, u_char g, u_char b)
                     58: {
                     59:        static const int        q2c[6] = { 0x00, 0x5f, 0x87, 0xaf, 0xd7, 0xff };
                     60:        int                     qr, qg, qb, cr, cg, cb, d, idx;
                     61:        int                     grey_avg, grey_idx, grey;
                     62: 
                     63:        /* Map RGB to 6x6x6 cube. */
                     64:        qr = colour_to_6cube(r); cr = q2c[qr];
                     65:        qg = colour_to_6cube(g); cg = q2c[qg];
                     66:        qb = colour_to_6cube(b); cb = q2c[qb];
                     67: 
                     68:        /* If we have hit the colour exactly, return early. */
                     69:        if (cr == r && cg == g && cb == b)
                     70:                return ((16 + (36 * qr) + (6 * qg) + qb) | COLOUR_FLAG_256);
                     71: 
                     72:        /* Work out the closest grey (average of RGB). */
                     73:        grey_avg = (r + g + b) / 3;
                     74:        if (grey_avg > 238)
                     75:                grey_idx = 23;
                     76:        else
                     77:                grey_idx = (grey_avg - 3) / 10;
                     78:        grey = 8 + (10 * grey_idx);
                     79: 
                     80:        /* Is grey or 6x6x6 colour closest? */
                     81:        d = colour_dist_sq(cr, cg, cb, r, g, b);
                     82:        if (colour_dist_sq(grey, grey, grey, r, g, b) < d)
                     83:                idx = 232 + grey_idx;
                     84:        else
                     85:                idx = 16 + (36 * qr) + (6 * qg) + qb;
                     86:        return (idx | COLOUR_FLAG_256);
                     87: }
                     88: 
                     89: /* Join RGB into a colour. */
                     90: int
                     91: colour_join_rgb(u_char r, u_char g, u_char b)
                     92: {
                     93:        return ((((int)((r) & 0xff)) << 16) |
                     94:            (((int)((g) & 0xff)) << 8) |
                     95:            (((int)((b) & 0xff))) | COLOUR_FLAG_RGB);
                     96: }
                     97: 
                     98: /* Split colour into RGB. */
                     99: void
                    100: colour_split_rgb(int c, u_char *r, u_char *g, u_char *b)
                    101: {
                    102:        *r = (c >> 16) & 0xff;
                    103:        *g = (c >> 8) & 0xff;
                    104:        *b = c & 0xff;
                    105: }
                    106: 
                    107: /* Convert colour to a string. */
                    108: const char *
                    109: colour_tostring(int c)
                    110: {
                    111:        static char     s[32];
                    112:        u_char          r, g, b;
                    113: 
                    114:        if (c & COLOUR_FLAG_RGB) {
                    115:                colour_split_rgb(c, &r, &g, &b);
                    116:                xsnprintf(s, sizeof s, "#%02x%02x%02x", r, g, b);
                    117:                return (s);
                    118:        }
                    119: 
                    120:        if (c & COLOUR_FLAG_256) {
                    121:                xsnprintf(s, sizeof s, "colour%u", c & 0xff);
                    122:                return (s);
                    123:        }
                    124: 
                    125:        switch (c) {
                    126:        case 0:
                    127:                return ("black");
                    128:        case 1:
                    129:                return ("red");
                    130:        case 2:
                    131:                return ("green");
                    132:        case 3:
                    133:                return ("yellow");
                    134:        case 4:
                    135:                return ("blue");
                    136:        case 5:
                    137:                return ("magenta");
                    138:        case 6:
                    139:                return ("cyan");
                    140:        case 7:
                    141:                return ("white");
                    142:        case 8:
                    143:                return ("default");
                    144:        case 90:
                    145:                return ("brightblack");
                    146:        case 91:
                    147:                return ("brightred");
                    148:        case 92:
                    149:                return ("brightgreen");
                    150:        case 93:
                    151:                return ("brightyellow");
                    152:        case 94:
                    153:                return ("brightblue");
                    154:        case 95:
                    155:                return ("brightmagenta");
                    156:        case 96:
                    157:                return ("brightcyan");
                    158:        case 97:
                    159:                return ("brightwhite");
                    160:        }
                    161:        return (NULL);
                    162: }
                    163: 
                    164: /* Convert colour from string. */
                    165: int
                    166: colour_fromstring(const char *s)
                    167: {
                    168:        const char      *errstr;
                    169:        const char      *cp;
                    170:        int              n;
                    171:        u_char           r, g, b;
                    172: 
                    173:        if (*s == '#' && strlen(s) == 7) {
                    174:                for (cp = s + 1; isxdigit((u_char) *cp); cp++)
                    175:                        ;
                    176:                if (*cp != '\0')
                    177:                        return (-1);
                    178:                n = sscanf(s + 1, "%2hhx%2hhx%2hhx", &r, &g, &b);
                    179:                if (n != 3)
                    180:                        return (-1);
                    181:                return (colour_join_rgb(r, g, b));
                    182:        }
                    183: 
                    184:        if (strncasecmp(s, "colour", (sizeof "colour") - 1) == 0) {
                    185:                n = strtonum(s + (sizeof "colour") - 1, 0, 255, &errstr);
                    186:                if (errstr != NULL)
                    187:                        return (-1);
                    188:                return (n | COLOUR_FLAG_256);
                    189:        }
                    190: 
                    191:        if (strcasecmp(s, "black") == 0 || strcmp(s, "0") == 0)
                    192:                return (0);
                    193:        if (strcasecmp(s, "red") == 0 || strcmp(s, "1") == 0)
                    194:                return (1);
                    195:        if (strcasecmp(s, "green") == 0 || strcmp(s, "2") == 0)
                    196:                return (2);
                    197:        if (strcasecmp(s, "yellow") == 0 || strcmp(s, "3") == 0)
                    198:                return (3);
                    199:        if (strcasecmp(s, "blue") == 0 || strcmp(s, "4") == 0)
                    200:                return (4);
                    201:        if (strcasecmp(s, "magenta") == 0 || strcmp(s, "5") == 0)
                    202:                return (5);
                    203:        if (strcasecmp(s, "cyan") == 0 || strcmp(s, "6") == 0)
                    204:                return (6);
                    205:        if (strcasecmp(s, "white") == 0 || strcmp(s, "7") == 0)
                    206:                return (7);
                    207:        if (strcasecmp(s, "default") == 0 || strcmp(s, "8") == 0)
                    208:                return (8);
                    209:        if (strcasecmp(s, "brightblack") == 0 || strcmp(s, "90") == 0)
                    210:                return (90);
                    211:        if (strcasecmp(s, "brightred") == 0 || strcmp(s, "91") == 0)
                    212:                return (91);
                    213:        if (strcasecmp(s, "brightgreen") == 0 || strcmp(s, "92") == 0)
                    214:                return (92);
                    215:        if (strcasecmp(s, "brightyellow") == 0 || strcmp(s, "93") == 0)
                    216:                return (93);
                    217:        if (strcasecmp(s, "brightblue") == 0 || strcmp(s, "94") == 0)
                    218:                return (94);
                    219:        if (strcasecmp(s, "brightmagenta") == 0 || strcmp(s, "95") == 0)
                    220:                return (95);
                    221:        if (strcasecmp(s, "brightcyan") == 0 || strcmp(s, "96") == 0)
                    222:                return (96);
                    223:        if (strcasecmp(s, "brightwhite") == 0 || strcmp(s, "97") == 0)
                    224:                return (97);
                    225:        return (-1);
                    226: }
                    227: 
                    228: /* Convert 256 colour palette to 16. */
                    229: u_char
                    230: colour_256to16(u_char c)
                    231: {
                    232:        static const u_char table[256] = {
                    233:                 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
                    234:                 0,  4,  4,  4, 12, 12,  2,  6,  4,  4, 12, 12,  2,  2,  6,  4,
                    235:                12, 12,  2,  2,  2,  6, 12, 12, 10, 10, 10, 10, 14, 12, 10, 10,
                    236:                10, 10, 10, 14,  1,  5,  4,  4, 12, 12,  3,  8,  4,  4, 12, 12,
                    237:                 2,  2,  6,  4, 12, 12,  2,  2,  2,  6, 12, 12, 10, 10, 10, 10,
                    238:                14, 12, 10, 10, 10, 10, 10, 14,  1,  1,  5,  4, 12, 12,  1,  1,
                    239:                 5,  4, 12, 12,  3,  3,  8,  4, 12, 12,  2,  2,  2,  6, 12, 12,
                    240:                10, 10, 10, 10, 14, 12, 10, 10, 10, 10, 10, 14,  1,  1,  1,  5,
                    241:                12, 12,  1,  1,  1,  5, 12, 12,  1,  1,  1,  5, 12, 12,  3,  3,
                    242:                 3,  7, 12, 12, 10, 10, 10, 10, 14, 12, 10, 10, 10, 10, 10, 14,
                    243:                 9,  9,  9,  9, 13, 12,  9,  9,  9,  9, 13, 12,  9,  9,  9,  9,
                    244:                13, 12,  9,  9,  9,  9, 13, 12, 11, 11, 11, 11,  7, 12, 10, 10,
                    245:                10, 10, 10, 14,  9,  9,  9,  9,  9, 13,  9,  9,  9,  9,  9, 13,
                    246:                 9,  9,  9,  9,  9, 13,  9,  9,  9,  9,  9, 13,  9,  9,  9,  9,
                    247:                 9, 13, 11, 11, 11, 11, 11, 15,  0,  0,  0,  0,  0,  0,  8,  8,
                    248:                 8,  8,  8,  8,  7,  7,  7,  7,  7,  7, 15, 15, 15, 15, 15, 15
                    249:        };
                    250: 
                    251:        return (table[c]);
                    252: }

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