source: libcaca/trunk/cucul/attr.c @ 2303

Last change on this file since 2303 was 2303, checked in by Sam Hocevar, 12 years ago
  • Changed most of the long ints in the API into C99 types. WARNING: this completely breaks compatibility with previous versions of libcaca on 64-bit systems.
  • Property svn:keywords set to Id
File size: 14.5 KB
Line 
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: attr.c 2303 2008-04-19 19:25:41Z sam $
7 *
8 *  This library is free software. It comes without any warranty, to
9 *  the extent permitted by applicable law. You can redistribute it
10 *  and/or modify it under the terms of the Do What The Fuck You Want
11 *  To Public License, Version 2, as published by Sam Hocevar. See
12 *  http://sam.zoy.org/wtfpl/COPYING for more details.
13 */
14
15/*
16 *  This file contains functions for attribute management and colourspace
17 *  conversions.
18 */
19
20#include "config.h"
21
22#include "cucul.h"
23#include "cucul_internals.h"
24
25static uint8_t nearest_ansi(uint16_t);
26
27/* RGB colours for the ANSI palette. There is no real standard, so we
28 * use the same values as gnome-terminal. The 7th colour (brown) is a bit
29 * special: 0xfa50 instead of 0xfaa0. */
30static const uint16_t ansitab16[16] =
31{
32    0xf000, 0xf00a, 0xf0a0, 0xf0aa, 0xfa00, 0xfa0a, 0xfa50, 0xfaaa,
33    0xf555, 0xf55f, 0xf5f5, 0xf5ff, 0xff55, 0xff5f, 0xfff5, 0xffff,
34};
35
36/* Same table, except on 14 bits (3-4-4-3) */
37static const uint16_t ansitab14[16] =
38{
39    0x3800, 0x3805, 0x3850, 0x3855, 0x3d00, 0x3d05, 0x3d28, 0x3d55,
40    0x3aaa, 0x3aaf, 0x3afa, 0x3aff, 0x3faa, 0x3faf, 0x3ffa, 0x3fff,
41};
42
43/** \brief Get the text attribute at the given coordinates.
44 *
45 *  Get the internal \e libcucul attribute value of the character at the
46 *  given coordinates. The attribute value has 32 significant bits,
47 *  organised as follows from MSB to LSB:
48 *  - 3 bits for the background alpha
49 *  - 4 bits for the background red component
50 *  - 4 bits for the background green component
51 *  - 3 bits for the background blue component
52 *  - 3 bits for the foreground alpha
53 *  - 4 bits for the foreground red component
54 *  - 4 bits for the foreground green component
55 *  - 3 bits for the foreground blue component
56 *  - 4 bits for the bold, italics, underline and blink flags
57 *
58 *  If the coordinates are outside the canvas boundaries, the current
59 *  attribute is returned.
60 *
61 *  This function never fails.
62 *
63 *  \param cv A handle to the libcucul canvas.
64 *  \param x X coordinate.
65 *  \param y Y coordinate.
66 *  \return The requested attribute.
67 */
68uint32_t cucul_get_attr(cucul_canvas_t const *cv, int x, int y)
69{
70    if(x < 0 || x >= (int)cv->width || y < 0 || y >= (int)cv->height)
71        return cv->curattr;
72
73    return cv->attrs[x + y * cv->width];
74}
75
76/** \brief Set the default character attribute.
77 *
78 *  Set the default character attribute for drawing. Attributes define
79 *  foreground and background colour, transparency, bold, italics and
80 *  underline styles, as well as blink. String functions such as
81 *  caca_printf() and graphical primitive functions such as caca_draw_line()
82 *  will use this attribute.
83 *
84 *  The value of \e attr is either:
85 *  - a 32-bit integer as returned by cucul_get_attr(), in which case it
86 *    also contains colour information,
87 *  - a combination (bitwise OR) of style values (\e CUCUL_UNDERLINE,
88 *    \e CUCUL_BLINK, \e CUCUL_BOLD and \e CUCUL_ITALICS), in which case
89 *    setting the attribute does not modify the current colour information.
90 *
91 *  To retrieve the current attribute value, use cucul_get_attr(-1,-1).
92 *
93 *  This function never fails.
94 *
95 *  \param cv A handle to the libcucul canvas.
96 *  \param attr The requested attribute value.
97 *  \return This function always returns 0.
98 */
99int cucul_set_attr(cucul_canvas_t *cv, uint32_t attr)
100{
101    if(attr < 0x00000010)
102        attr = (cv->curattr & 0xfffffff0) | attr;
103
104    cv->curattr = attr;
105
106    return 0;
107}
108
109/** \brief Set the character attribute at the given coordinates.
110 *
111 *  Set the character attribute, without changing the character's value. If
112 *  the character at the given coordinates is a fullwidth character, both
113 *  cells' attributes are replaced.
114 *
115 *  The value of \e attr is either:
116 *  - a 32-bit integer as returned by cucul_get_attr(), in which case it
117 *    also contains colour information,
118 *  - a combination (bitwise OR) of style values (\e CUCUL_UNDERLINE,
119 *    \e CUCUL_BLINK, \e CUCUL_BOLD and \e CUCUL_ITALICS), in which case
120 *    setting the attribute does not modify the current colour information.
121 *
122 *  This function never fails.
123 *
124 *  \param cv A handle to the libcucul canvas.
125 *  \param x X coordinate.
126 *  \param y Y coordinate.
127 *  \param attr The requested attribute value.
128 *  \return This function always returns 0.
129 */
130int cucul_put_attr(cucul_canvas_t *cv, int x, int y, uint32_t attr)
131{
132    uint32_t *curattr, *curchar;
133
134    if(x < 0 || x >= (int)cv->width || y < 0 || y >= (int)cv->height)
135        return 0;
136
137    curchar = cv->chars + x + y * cv->width;
138    curattr = cv->attrs + x + y * cv->width;
139
140    if(attr < 0x00000010)
141        curattr[0] = (curattr[0] & 0xfffffff0) | attr;
142    else
143        curattr[0] = attr;
144
145    if(x && curchar[0] == CUCUL_MAGIC_FULLWIDTH)
146        curattr[-1] = curattr[0];
147    else if(x + 1 < (int)cv->width && curchar[1] == CUCUL_MAGIC_FULLWIDTH)
148        curattr[1] = curattr[0];
149
150    return 0;
151}
152
153/** \brief Set the default colour pair for text (ANSI version).
154 *
155 *  Set the default ANSI colour pair for text drawing. String functions such
156 *  as caca_printf() and graphical primitive functions such as caca_draw_line()
157 *  will use these attributes.
158 *
159 *  Color values are those defined in cucul.h, such as CUCUL_RED
160 *  or CUCUL_TRANSPARENT.
161 *
162 *  If an error occurs, 0 is returned and \b errno is set accordingly:
163 *  - \c EINVAL At least one of the colour values is invalid.
164 *
165 *  \param cv A handle to the libcucul canvas.
166 *  \param fg The requested ANSI foreground colour.
167 *  \param bg The requested ANSI background colour.
168 *  \return 0 in case of success, -1 if an error occurred.
169 */
170int cucul_set_color_ansi(cucul_canvas_t *cv, uint8_t fg, uint8_t bg)
171{
172    uint32_t attr;
173
174    if(fg > 0x20 || bg > 0x20)
175    {
176        seterrno(EINVAL);
177        return -1;
178    }
179
180    attr = ((uint32_t)(bg | 0x40) << 18) | ((uint32_t)(fg | 0x40) << 4);
181    cv->curattr = (cv->curattr & 0x0000000f) | attr;
182
183    return 0;
184}
185
186/** \brief Set the default colour pair for text (truecolor version).
187 *
188 *  Set the default ARGB colour pair for text drawing. String functions such
189 *  as caca_printf() and graphical primitive functions such as caca_draw_line()
190 *  will use these attributes.
191 *
192 *  Colors are 16-bit ARGB values, each component being coded on 4 bits. For
193 *  instance, 0xf088 is solid dark cyan (A=15 R=0 G=8 B=8), and 0x8fff is
194 *  white with 50% alpha (A=8 R=15 G=15 B=15).
195 *
196 *  This function never fails.
197 *
198 *  \param cv A handle to the libcucul canvas.
199 *  \param fg The requested ARGB foreground colour.
200 *  \param bg The requested ARGB background colour.
201 *  \return This function always returns 0.
202 */
203int cucul_set_color_argb(cucul_canvas_t *cv, uint16_t fg, uint16_t bg)
204{
205    uint32_t attr;
206
207    if(fg < 0x100)
208        fg += 0x100;
209
210    if(bg < 0x100)
211        bg += 0x100;
212
213    fg = ((fg >> 1) & 0x7ff) | ((fg >> 13) << 11);
214    bg = ((bg >> 1) & 0x7ff) | ((bg >> 13) << 11);
215
216    attr = ((uint32_t)bg << 18) | ((uint32_t)fg << 4);
217    cv->curattr = (cv->curattr & 0x0000000f) | attr;
218
219    return 0;
220}
221
222/** \brief Get DOS ANSI information from attribute.
223 *
224 *  Get the ANSI colour pair for a given attribute. The returned value is
225 *  an 8-bit value whose higher 4 bits are the background colour and lower
226 *  4 bits are the foreground colour.
227 *
228 *  If the attribute has ARGB colours, the nearest colour is used. Special
229 *  attributes such as \e CUCUL_DEFAULT and \e CUCUL_TRANSPARENT are not
230 *  handled and are both replaced with \e CUCUL_LIGHTGRAY for the foreground
231 *  colour and \e CUCUL_BLACK for the background colour.
232 *
233 *  This function never fails. If the attribute value is outside the expected
234 *  32-bit range, higher order bits are simply ignored.
235 *
236 *  \param attr The requested attribute value.
237 *  \return The corresponding DOS ANSI value.
238 */
239uint8_t cucul_attr_to_ansi(uint32_t attr)
240{
241    uint8_t fg = nearest_ansi((attr >> 4) & 0x3fff);
242    uint8_t bg = nearest_ansi(attr >> 18);
243
244    return (fg < 0x10 ? fg : CUCUL_LIGHTGRAY)
245            | ((bg < 0x10 ? bg : CUCUL_BLACK) << 4);
246}
247
248/** \brief Get ANSI foreground information from attribute.
249 *
250 *  Get the ANSI foreground colour value for a given attribute. The returned
251 *  value is either one of the \e CUCUL_RED, \e CUCUL_BLACK etc. predefined
252 *  colours, or the special value \e CUCUL_DEFAULT meaning the media's
253 *  default foreground value, or the special value \e CUCUL_TRANSPARENT.
254 *
255 *  If the attribute has ARGB colours, the nearest colour is returned.
256 *
257 *  This function never fails. If the attribute value is outside the expected
258 *  32-bit range, higher order bits are simply ignored.
259 *
260 *  \param attr The requested attribute value.
261 *  \return The corresponding ANSI foreground value.
262 */
263uint8_t cucul_attr_to_ansi_fg(uint32_t attr)
264{
265    return nearest_ansi(((uint16_t)attr >> 4) & 0x3fff);
266}
267
268/** \brief Get ANSI background information from attribute.
269 *
270 *  Get the ANSI background colour value for a given attribute. The returned
271 *  value is either one of the \e CUCUL_RED, \e CUCUL_BLACK etc. predefined
272 *  colours, or the special value \e CUCUL_DEFAULT meaning the media's
273 *  default background value, or the special value \e CUCUL_TRANSPARENT.
274 *
275 *  If the attribute has ARGB colours, the nearest colour is returned.
276 *
277 *  This function never fails. If the attribute value is outside the expected
278 *  32-bit range, higher order bits are simply ignored.
279 *
280 *  \param attr The requested attribute value.
281 *  \return The corresponding ANSI background value.
282 */
283uint8_t cucul_attr_to_ansi_bg(uint32_t attr)
284{
285    return nearest_ansi(attr >> 18);
286}
287
288/** \brief Get 12-bit RGB foreground information from attribute.
289 *
290 *  Get the 12-bit foreground colour value for a given attribute. The returned
291 *  value is a native-endian encoded integer with each red, green and blue
292 *  values encoded on 8 bits in the following order:
293 *   - 8-11 most significant bits: red
294 *   - 4-7 most significant bits: green
295 *   - least significant bits: blue
296 *
297 *  This function never fails. If the attribute value is outside the expected
298 *  32-bit range, higher order bits are simply ignored.
299 *
300 *  \param attr The requested attribute value.
301 *  \return The corresponding 12-bit RGB foreground value.
302 */
303uint16_t cucul_attr_to_rgb12_fg(uint32_t attr)
304{
305    uint16_t fg = (attr >> 4) & 0x3fff;
306
307    if(fg < (0x10 | 0x40))
308        return ansitab16[fg ^ 0x40] & 0x0fff;
309
310    if(fg == (CUCUL_DEFAULT | 0x40))
311        return ansitab16[CUCUL_LIGHTGRAY] & 0x0fff;
312
313    if(fg == (CUCUL_TRANSPARENT | 0x40))
314        return ansitab16[CUCUL_LIGHTGRAY] & 0x0fff;
315
316    return (fg << 1) & 0x0fff;
317}
318
319/** \brief Get 12-bit RGB background information from attribute.
320 *
321 *  Get the 12-bit background colour value for a given attribute. The returned
322 *  value is a native-endian encoded integer with each red, green and blue
323 *  values encoded on 8 bits in the following order:
324 *   - 8-11 most significant bits: red
325 *   - 4-7 most significant bits: green
326 *   - least significant bits: blue
327 *
328 *  This function never fails. If the attribute value is outside the expected
329 *  32-bit range, higher order bits are simply ignored.
330 *
331 *  \param attr The requested attribute value.
332 *  \return The corresponding 12-bit RGB background value.
333 */
334uint16_t cucul_attr_to_rgb12_bg(uint32_t attr)
335{
336    uint16_t bg = attr >> 18;
337
338    if(bg < (0x10 | 0x40))
339        return ansitab16[bg ^ 0x40] & 0x0fff;
340
341    if(bg == (CUCUL_DEFAULT | 0x40))
342        return ansitab16[CUCUL_BLACK] & 0x0fff;
343
344    if(bg == (CUCUL_TRANSPARENT | 0x40))
345        return ansitab16[CUCUL_BLACK] & 0x0fff;
346
347    return (bg << 1) & 0x0fff;
348}
349
350/** \brief Get 64-bit ARGB information from attribute.
351 *
352 *  Get the 64-bit colour and alpha values for a given attribute. The values
353 *  are written as 8-bit integers in the \e argb array in the following order:
354 *   - \e argb[0]: background alpha value
355 *   - \e argb[1]: background red value
356 *   - \e argb[2]: background green value
357 *   - \e argb[3]: background blue value
358 *   - \e argb[4]: foreground alpha value
359 *   - \e argb[5]: foreground red value
360 *   - \e argb[6]: foreground green value
361 *   - \e argb[7]: foreground blue value
362 *
363 *  This function never fails. If the attribute value is outside the expected
364 *  32-bit range, higher order bits are simply ignored.
365 *
366 *  \param attr The requested attribute value.
367 *  \param argb An array of 8-bit integers.
368 */
369void cucul_attr_to_argb64(uint32_t attr, uint8_t argb[8])
370{
371    uint16_t fg = (attr >> 4) & 0x3fff;
372    uint16_t bg = attr >> 18;
373
374    if(bg < (0x10 | 0x40))
375        bg = ansitab16[bg ^ 0x40];
376    else if(bg == (CUCUL_DEFAULT | 0x40))
377        bg = ansitab16[CUCUL_BLACK];
378    else if(bg == (CUCUL_TRANSPARENT | 0x40))
379        bg = 0x0fff;
380    else
381        bg = ((bg << 2) & 0xf000) | ((bg << 1) & 0x0fff);
382
383    argb[0] = bg >> 12;
384    argb[1] = (bg >> 8) & 0xf;
385    argb[2] = (bg >> 4) & 0xf;
386    argb[3] = bg & 0xf;
387
388    if(fg < (0x10 | 0x40))
389        fg = ansitab16[fg ^ 0x40];
390    else if(fg == (CUCUL_DEFAULT | 0x40))
391        fg = ansitab16[CUCUL_LIGHTGRAY];
392    else if(fg == (CUCUL_TRANSPARENT | 0x40))
393        fg = 0x0fff;
394    else
395        fg = ((fg << 2) & 0xf000) | ((fg << 1) & 0x0fff);
396
397    argb[4] = fg >> 12;
398    argb[5] = (fg >> 8) & 0xf;
399    argb[6] = (fg >> 4) & 0xf;
400    argb[7] = fg & 0xf;
401}
402
403/*
404 * XXX: the following functions are local
405 */
406
407static uint8_t nearest_ansi(uint16_t argb14)
408{
409    unsigned int i, best, dist;
410
411    if(argb14 < (0x10 | 0x40))
412        return argb14 ^ 0x40;
413
414    if(argb14 == (CUCUL_DEFAULT | 0x40) || argb14 == (CUCUL_TRANSPARENT | 0x40))
415        return argb14 ^ 0x40;
416
417    if(argb14 < 0x0fff) /* too transparent */
418        return CUCUL_TRANSPARENT;
419
420    best = CUCUL_DEFAULT;
421    dist = 0x3fff;
422    for(i = 0; i < 16; i++)
423    {
424        unsigned int d = 0;
425        int a, b;
426
427        a = (ansitab14[i] >> 7) & 0xf;
428        b = (argb14 >> 7) & 0xf;
429        d += (a - b) * (a - b);
430
431        a = (ansitab14[i] >> 3) & 0xf;
432        b = (argb14 >> 3) & 0xf;
433        d += (a - b) * (a - b);
434
435        a = (ansitab14[i] << 1) & 0xf;
436        b = (argb14 << 1) & 0xf;
437        d += (a - b) * (a - b);
438
439        if(d < dist)
440        {
441            dist = d;
442            best = i;
443        }
444    }
445
446    return best;
447}
448
449#define RGB12TO24(i) \
450   (((uint32_t)((i & 0xf00) >> 8) * 0x110000) \
451  | ((uint32_t)((i & 0x0f0) >> 4) * 0x001100) \
452  | ((uint32_t)(i & 0x00f) * 0x000011))
453
454uint32_t _cucul_attr_to_rgb24fg(uint32_t attr)
455{
456    return RGB12TO24(cucul_attr_to_rgb12_fg(attr));
457}
458
459uint32_t _cucul_attr_to_rgb24bg(uint32_t attr)
460{
461    return RGB12TO24(cucul_attr_to_rgb12_bg(attr));
462}
463
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