Nelze vybrat více než 25 témat Téma musí začínat písmenem nebo číslem, může obsahovat pomlčky („-“) a může být dlouhé až 35 znaků.

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249
  1. /*
  2. * libcucul Canvas for ultrafast compositing of Unicode letters
  3. * Copyright (c) 2002-2006 Sam Hocevar <sam@zoy.org>
  4. * All Rights Reserved
  5. *
  6. * $Id$
  7. *
  8. * This library is free software; you can redistribute it and/or
  9. * modify it under the terms of the Do What The Fuck You Want To
  10. * Public License, Version 2, as published by Sam Hocevar. See
  11. * http://sam.zoy.org/wtfpl/COPYING for more details.
  12. */
  13. /*
  14. * This file contains functions for converting colour values between
  15. * various colourspaces.
  16. */
  17. #include "config.h"
  18. #include "common.h"
  19. #if defined(HAVE_ERRNO_H)
  20. # include <errno.h>
  21. #endif
  22. #include "cucul.h"
  23. #include "cucul_internals.h"
  24. static const uint16_t ansitab[16] =
  25. {
  26. 0xf000, 0xf008, 0xf080, 0xf088, 0xf800, 0xf808, 0xf880, 0xf888,
  27. 0xf444, 0xf44f, 0xf4f4, 0xf4ff, 0xff44, 0xff4f, 0xfff4, 0xffff,
  28. };
  29. /** \brief Set the default colour pair.
  30. *
  31. * This function sets the default ANSI colour pair. String functions such as
  32. * caca_printf() and graphical primitive functions such as caca_draw_line()
  33. * will use these colours.
  34. *
  35. * Color values are those defined in cucul.h, such as CUCUL_COLOR_RED
  36. * or CUCUL_COLOR_TRANSPARENT.
  37. *
  38. * If an error occurs, -1 is returned and \b errno is set accordingly:
  39. * - \c EINVAL At least one of the colour values is invalid.
  40. *
  41. * \param cv A handle to the libcucul canvas.
  42. * \param fg The requested foreground colour.
  43. * \param bg The requested background colour.
  44. * \return 0 in case of success, -1 if an error occurred.
  45. */
  46. int cucul_set_color(cucul_canvas_t *cv, unsigned char fg, unsigned char bg)
  47. {
  48. if(fg > 0x20 || bg > 0x20)
  49. {
  50. #if defined(HAVE_ERRNO_H)
  51. errno = EINVAL;
  52. #endif
  53. return -1;
  54. }
  55. cv->fgcolor = fg;
  56. cv->bgcolor = bg;
  57. return 0;
  58. }
  59. /** \brief Set the default colour pair (truecolor version).
  60. *
  61. * This function sets the default colour pair. String functions such as
  62. * caca_printf() and graphical primitive functions such as caca_draw_line()
  63. * will use these colours.
  64. *
  65. * Colors are 16-bit ARGB values, each component being coded on 4 bits. For
  66. * instance, 0xf088 is solid dark cyan (A=15 R=0 G=8 B=8), and 0x8fff is
  67. * white with 50% alpha (A=8 R=15 G=15 B=15).
  68. *
  69. * If an error occurs, -1 is returned and \b errno is set accordingly:
  70. * - \c EINVAL At least one of the colour values is invalid.
  71. *
  72. * \param cv A handle to the libcucul canvas.
  73. * \param fg The requested foreground colour.
  74. * \param bg The requested background colour.
  75. * \return 0 in case of success, -1 if an error occurred.
  76. */
  77. int cucul_set_truecolor(cucul_canvas_t *cv, unsigned int fg, unsigned int bg)
  78. {
  79. if(fg > 0xffff || bg > 0xffff)
  80. {
  81. #if defined(HAVE_ERRNO_H)
  82. errno = EINVAL;
  83. #endif
  84. return -1;
  85. }
  86. if(fg < 0x100)
  87. fg += 0x100;
  88. if(bg < 0x100)
  89. bg += 0x100;
  90. cv->fgcolor = fg;
  91. cv->bgcolor = bg;
  92. return 0;
  93. }
  94. /*
  95. * XXX: the following functions are local
  96. */
  97. static uint8_t nearest_ansi(uint16_t argb16, uint8_t def)
  98. {
  99. unsigned int i, best, dist;
  100. if(argb16 < CUCUL_COLOR_DEFAULT)
  101. return argb16;
  102. if(argb16 == CUCUL_COLOR_DEFAULT || argb16 == CUCUL_COLOR_TRANSPARENT)
  103. return def;
  104. if(argb16 < 0x5fff) /* too transparent, return default colour */
  105. return def;
  106. best = def;
  107. dist = 0xffff;
  108. for(i = 0; i < 16; i++)
  109. {
  110. unsigned int d = 0;
  111. int a, b;
  112. a = (ansitab[i] >> 8) & 0xf;
  113. b = (argb16 >> 8) & 0xf;
  114. d += (a - b) * (a - b);
  115. a = (ansitab[i] >> 4) & 0xf;
  116. b = (argb16 >> 4) & 0xf;
  117. d += (a - b) * (a - b);
  118. a = ansitab[i] & 0xf;
  119. b = argb16 & 0xf;
  120. d += (a - b) * (a - b);
  121. if(d < dist)
  122. {
  123. dist = d;
  124. best = i;
  125. }
  126. }
  127. return best;
  128. }
  129. uint8_t _cucul_argb32_to_ansi8(uint32_t ch)
  130. {
  131. uint16_t fg = ch & 0xffff;
  132. uint16_t bg = ch >> 16;
  133. return nearest_ansi(fg, CUCUL_COLOR_LIGHTGRAY)
  134. | (nearest_ansi(bg, CUCUL_COLOR_BLACK) << 4);
  135. }
  136. uint8_t _cucul_argb32_to_ansi4fg(uint32_t ch)
  137. {
  138. return nearest_ansi(ch & 0xffff, CUCUL_COLOR_LIGHTGRAY);
  139. }
  140. uint8_t _cucul_argb32_to_ansi4bg(uint32_t ch)
  141. {
  142. return nearest_ansi(ch >> 16, CUCUL_COLOR_BLACK);
  143. }
  144. uint16_t _cucul_argb32_to_rgb12fg(uint32_t ch)
  145. {
  146. uint16_t fg = ch & 0xffff;
  147. if(fg < CUCUL_COLOR_DEFAULT)
  148. return ansitab[fg] & 0x0fff;
  149. if(fg == CUCUL_COLOR_DEFAULT)
  150. return ansitab[CUCUL_COLOR_LIGHTGRAY] & 0x0fff;
  151. if(fg == CUCUL_COLOR_TRANSPARENT)
  152. return ansitab[CUCUL_COLOR_LIGHTGRAY] & 0x0fff;
  153. return fg & 0x0fff;
  154. }
  155. uint16_t _cucul_argb32_to_rgb12bg(uint32_t ch)
  156. {
  157. uint16_t bg = ch >> 16;
  158. if(bg < CUCUL_COLOR_DEFAULT)
  159. return ansitab[bg] & 0x0fff;
  160. if(bg == CUCUL_COLOR_DEFAULT)
  161. return ansitab[CUCUL_COLOR_BLACK] & 0x0fff;
  162. if(bg == CUCUL_COLOR_TRANSPARENT)
  163. return ansitab[CUCUL_COLOR_BLACK] & 0x0fff;
  164. return bg & 0x0fff;
  165. }
  166. #define RGB12TO24(i) \
  167. (((uint32_t)((i & 0xf00) >> 8) * 0x110000) \
  168. | ((uint32_t)((i & 0x0f0) >> 4) * 0x001100) \
  169. | ((uint32_t)(i & 0x00f) * 0x000011))
  170. uint32_t _cucul_argb32_to_rgb24fg(uint32_t ch)
  171. {
  172. return RGB12TO24(_cucul_argb32_to_rgb12fg(ch));
  173. }
  174. uint32_t _cucul_argb32_to_rgb24bg(uint32_t ch)
  175. {
  176. return RGB12TO24(_cucul_argb32_to_rgb12bg(ch));
  177. }
  178. void _cucul_argb32_to_argb4(uint32_t ch, uint8_t argb[8])
  179. {
  180. uint16_t fg = ch & 0xffff;
  181. uint16_t bg = ch >> 16;
  182. if(fg < CUCUL_COLOR_DEFAULT)
  183. fg = ansitab[fg];
  184. else if(fg == CUCUL_COLOR_DEFAULT)
  185. fg = ansitab[CUCUL_COLOR_LIGHTGRAY];
  186. else if(fg == CUCUL_COLOR_TRANSPARENT)
  187. fg = 0x0fff;
  188. if(bg < CUCUL_COLOR_DEFAULT)
  189. bg = ansitab[bg];
  190. else if(bg == CUCUL_COLOR_DEFAULT)
  191. bg = ansitab[CUCUL_COLOR_BLACK];
  192. else if(bg == CUCUL_COLOR_TRANSPARENT)
  193. bg = 0x0fff;
  194. argb[0] = bg >> 12;
  195. argb[1] = (bg >> 8) & 0xf;
  196. argb[2] = (bg >> 4) & 0xf;
  197. argb[3] = bg & 0xf;
  198. argb[4] = fg >> 12;
  199. argb[5] = (fg >> 8) & 0xf;
  200. argb[6] = (fg >> 4) & 0xf;
  201. argb[7] = fg & 0xf;
  202. }