diff --git a/sys/teken/libteken/teken.3 b/sys/teken/libteken/teken.3 index 70bed07a57b5..b42405f07c0f 100644 --- a/sys/teken/libteken/teken.3 +++ b/sys/teken/libteken/teken.3 @@ -24,7 +24,7 @@ .\" .\" $FreeBSD$ .\" -.Dd May 9, 2011 +.Dd Mar 13, 2017 .Dt TEKEN 3 .Os .Sh NAME @@ -57,6 +57,8 @@ .Ft const char * .Fn teken_get_sequence "teken_t *t" "unsigned int id" .Ft teken_color_t +.Fn teken_256to16 "teken_color_t color" +.Ft teken_color_t .Fn teken_256to8 "teken_color_t color" .Ft void .Fn teken_get_defattr_cons25 "teken_t *t" "int *fg" "int *bg" @@ -163,10 +165,22 @@ This library also provides a set of functions that shouldn't be used in any modern applications. .Pp The +.Fn teken_256to16 +function converts an xterm-256 256-color code to an xterm 16-color code +whose color with default palettes is as similar as possible (not very +similar). +The lower 3 bits of the result are the ANSI color and the next lowest +bit is brightness. +Other layers (hardare and software) that only support 16 colors can use +this to avoid knowing the details of 256-color codes. +.Pp +The .Fn teken_256to8 -function converts a color code to one of the 8 primary colors, allowing -the terminal to be rendered on graphics hardware that only supports 8 or -16 colors (e.g. VGA). +function is similar to +.Fn teken_256to16 +except it converts to an ANSI 8-color code. +This is more accurate than discarding the brigtness bit in the result of +.Fn teken_256to16 . .Pp The .Fn teken_get_defattr_cons25 diff --git a/sys/teken/teken.c b/sys/teken/teken.c index 8834390dec49..6a9842d53848 100644 --- a/sys/teken/teken.c +++ b/sys/teken/teken.c @@ -452,55 +452,203 @@ teken_state_numbers(teken_t *t, teken_char_t c) return (0); } +#define k TC_BLACK +#define b TC_BLUE +#define y TC_BROWN +#define c TC_CYAN +#define g TC_GREEN +#define m TC_MAGENTA +#define r TC_RED +#define w TC_WHITE +#define K (TC_BLACK | TC_LIGHT) +#define B (TC_BLUE | TC_LIGHT) +#define Y (TC_BROWN | TC_LIGHT) +#define C (TC_CYAN | TC_LIGHT) +#define G (TC_GREEN | TC_LIGHT) +#define M (TC_MAGENTA | TC_LIGHT) +#define R (TC_RED | TC_LIGHT) +#define W (TC_WHITE | TC_LIGHT) + +/** + * The xterm-256 color map has steps of 0x28 (in the range 0-0xff), except + * for the first step which is 0x5f. Scale to the range 0-6 by dividing + * by 0x28 and rounding down. The range of 0-5 cannot represent the + * larger first step. + * + * This table is generated by the follow rules: + * - if all components are equal, the result is black for (0, 0, 0) and + * (2, 2, 2), else white; otherwise: + * - subtract the smallest component from all components + * - if this gives only one nonzero component, then that is the color + * - else if one component is 2 or more larger than the other nonzero one, + * then that component gives the color + * - else there are 2 nonzero components. The color is that of a small + * equal mixture of these components (cyan, yellow or magenta). E.g., + * (0, 5, 6) (Turquoise2) is a much purer cyan than (0, 2, 3) + * (DeepSkyBlue4), but we map both to cyan since we can't represent + * delicate shades of either blue or cyan and blue would be worse. + * Here it is important that components of 1 never occur. Blue would + * be twice as large as green in (0, 1, 2). + */ +static const teken_color_t teken_256to8tab[] = { + /* xterm-16+ 8 dark colors: */ + 0, r, g, y, b, m, c, w, + + /* xterm-16+ 8 light colors: */ + 0, R, G, Y, B, M, C, W, + + /* Red0 submap. */ + k, b, b, b, b, b, + g, c, c, b, b, b, + g, c, c, c, b, b, + g, g, c, c, c, b, + g, g, g, c, c, c, + g, g, g, g, c, c, + + /* Red2 submap. */ + r, m, m, b, b, b, + y, k, b, b, b, b, + y, g, c, c, b, b, + g, g, c, c, c, b, + g, g, g, c, c, c, + g, g, g, g, c, c, + + /* Red3 submap. */ + r, m, m, m, b, b, + y, r, m, m, b, b, + y, y, w, b, b, b, + y, y, g, c, c, b, + g, g, g, c, c, c, + g, g, g, g, c, c, + + /* Red4 submap. */ + r, r, m, m, m, b, + r, r, m, m, m, b, + y, y, r, m, m, b, + y, y, y, w, b, b, + y, y, y, g, c, c, + g, g, g, g, c, c, + + /* Red5 submap. */ + r, r, r, m, m, m, + r, r, r, m, m, m, + r, r, r, m, m, m, + y, y, y, r, m, m, + y, y, y, y, w, b, + y, y, y, y, g, c, + + /* Red6 submap. */ + r, r, r, r, m, m, + r, r, r, r, m, m, + r, r, r, r, m, m, + r, r, r, r, m, m, + y, y, y, y, r, m, + y, y, y, y, y, w, + + /* Grey submap. */ + k, k, k, k, k, k, + k, k, k, k, k, k, + w, w, w, w, w, w, + w, w, w, w, w, w, +}; + +/* + * This table is generated from the previous one by setting TC_LIGHT for + * entries whose luminosity in the xterm256 color map is 60% or larger. + * Thus the previous table is currently not really needed. It will be + * used for different fine tuning of the tables. + */ +static const teken_color_t teken_256to16tab[] = { + /* xterm-16+ 8 dark colors: */ + 0, r, g, y, b, m, c, w, + + /* xterm-16+ 8 light colors: */ + 0, R, G, Y, B, M, C, W, + + /* Red0 submap. */ + k, b, b, b, b, b, + g, c, c, b, b, b, + g, c, c, c, b, b, + g, g, c, c, c, b, + g, g, g, c, c, c, + g, g, g, g, c, c, + + /* Red2 submap. */ + r, m, m, b, b, b, + y, K, b, b, B, B, + y, g, c, c, B, B, + g, g, c, c, C, B, + g, G, G, C, C, C, + g, G, G, G, C, C, + + /* Red3 submap. */ + r, m, m, m, b, b, + y, r, m, m, B, B, + y, y, w, B, B, B, + y, y, G, C, C, B, + g, G, G, C, C, C, + g, G, G, G, C, C, + + /* Red4 submap. */ + r, r, m, m, m, b, + r, r, m, m, M, B, + y, y, R, M, M, B, + y, y, Y, W, B, B, + y, Y, Y, G, C, C, + g, G, G, G, C, C, + + /* Red5 submap. */ + r, r, r, m, m, m, + r, R, R, M, M, M, + r, R, R, M, M, M, + y, Y, Y, R, M, M, + y, Y, Y, Y, W, B, + y, Y, Y, Y, G, C, + + /* Red6 submap. */ + r, r, r, r, m, m, + r, R, R, R, M, M, + r, R, R, R, M, M, + r, R, R, R, M, M, + y, Y, Y, Y, R, M, + y, Y, Y, Y, Y, W, + + /* Grey submap. */ + k, k, k, k, k, k, + K, K, K, K, K, K, + w, w, w, w, w, w, + W, W, W, W, W, W, +}; + +#undef k +#undef b +#undef y +#undef c +#undef g +#undef m +#undef r +#undef w +#undef K +#undef B +#undef Y +#undef C +#undef G +#undef M +#undef R +#undef W + teken_color_t teken_256to8(teken_color_t c) { - unsigned int r, g, b; - if (c < 16) { - /* Traditional color indices. */ - return (c % 8); - } else if (c >= 244) { - /* Upper grayscale colors. */ - return (TC_WHITE); - } else if (c >= 232) { - /* Lower grayscale colors. */ - return (TC_BLACK); - } + return (teken_256to8tab[c % 256]); +} - /* Convert to RGB. */ - c -= 16; - b = c % 6; - g = (c / 6) % 6; - r = c / 36; +teken_color_t +teken_256to16(teken_color_t c) +{ - if (r < g) { - /* Possibly green. */ - if (g < b) - return (TC_BLUE); - else if (g > b) - return (TC_GREEN); - else - return (TC_CYAN); - } else if (r > g) { - /* Possibly red. */ - if (r < b) - return (TC_BLUE); - else if (r > b) - return (TC_RED); - else - return (TC_MAGENTA); - } else { - /* Possibly brown. */ - if (g < b) - return (TC_BLUE); - else if (g > b) - return (TC_BROWN); - else if (r < 3) - return (TC_BLACK); - else - return (TC_WHITE); - } + return (teken_256to16tab[c % 256]); } static const char * const special_strings_cons25[] = { diff --git a/sys/teken/teken.h b/sys/teken/teken.h index 27d1ce404740..7e3716bec55a 100644 --- a/sys/teken/teken.h +++ b/sys/teken/teken.h @@ -56,6 +56,7 @@ typedef unsigned char teken_color_t; #define TC_CYAN 6 #define TC_WHITE 7 #define TC_NCOLORS 8 +#define TC_LIGHT 8 /* ORed with the others. */ typedef struct { teken_unit_t tp_row; @@ -203,6 +204,7 @@ void teken_set_8bit(teken_t *); void teken_set_cons25(teken_t *); /* Color conversion. */ +teken_color_t teken_256to16(teken_color_t); teken_color_t teken_256to8(teken_color_t); #endif /* !_TEKEN_H_ */