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

Last change on this file since 2303 was 2303, checked in by Sam Hocevar, 15 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: 15.9 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: font.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 font handling functions.
17 */
18
19#include "config.h"
20
21#if !defined(__KERNEL__)
22#   if defined(HAVE_ENDIAN_H)
23#       include <endian.h>
24#   endif
25#   include <stdio.h>
26#   include <stdlib.h>
27#   include <string.h>
28#endif
29
30#include "cucul.h"
31#include "cucul_internals.h"
32
33/* Internal fonts */
34#include "mono9.data"
35#include "monobold12.data"
36
37/* Helper structures for font loading */
38#if !defined(_DOXYGEN_SKIP_ME)
39struct font_header
40{
41    uint32_t control_size, data_size;
42    uint16_t version, blocks;
43    uint32_t glyphs;
44    uint16_t bpp, width, height, maxwidth, maxheight, flags;
45};
46
47struct block_info
48{
49    uint32_t start, stop, index;
50};
51
52struct glyph_info
53{
54    uint16_t width, height;
55    uint32_t data_offset;
56};
57
58struct cucul_font
59{
60    struct font_header header;
61
62    struct block_info *block_list;
63    uint32_t *user_block_list;
64    struct glyph_info *glyph_list;
65    uint8_t *font_data;
66
67    uint8_t *private;
68};
69#endif
70
71#define DECLARE_UNPACKGLYPH(bpp) \
72    static inline void \
73      unpack_glyph ## bpp(uint8_t *glyph, uint8_t *packed_data, \
74                          unsigned int n) \
75{ \
76    unsigned int i; \
77    \
78    for(i = 0; i < n; i++) \
79    { \
80        uint8_t pixel = packed_data[i / (8 / bpp)]; \
81        pixel >>= bpp * ((8 / bpp) - 1 - (i % (8 / bpp))); \
82        pixel %= (1 << bpp); \
83        pixel *= 0xff / ((1 << bpp) - 1); \
84        *glyph++ = pixel; \
85    } \
86}
87
88DECLARE_UNPACKGLYPH(4)
89DECLARE_UNPACKGLYPH(2)
90DECLARE_UNPACKGLYPH(1)
91
92/** \brief Load a font from memory for future use.
93 *
94 *  This function loads a font and returns a handle to its internal
95 *  structure. The handle can then be used with cucul_render_canvas()
96 *  for bitmap output.
97 *
98 *  Internal fonts can also be loaded: if \c size is set to 0, \c data must
99 *  be a string containing the internal font name.
100 *
101 *  If \c size is non-zero, the \c size bytes of memory at address \c data
102 *  are loaded as a font. This memory are must not be freed by the calling
103 *  program until the font handle has been freed with cucul_free_font().
104 *
105 *  If an error occurs, NULL is returned and \b errno is set accordingly:
106 *  - \c ENOENT Requested built-in font does not exist.
107 *  - \c EINVAL Invalid font data in memory area.
108 *  - \c ENOMEM Not enough memory to allocate font structure.
109 *
110 *  \param data The memory area containing the font or its name.
111 *  \param size The size of the memory area, or 0 if the font name is given.
112 *  \return A font handle or NULL in case of error.
113 */
114cucul_font_t *cucul_load_font(void const *data, unsigned int size)
115{
116    cucul_font_t *f;
117    unsigned int i;
118
119    if(size == 0)
120    {
121        if(!strcasecmp(data, "Monospace 9"))
122            return cucul_load_font((char *)&mono9_data, mono9_size);
123        if(!strcasecmp(data, "Monospace Bold 12"))
124            return cucul_load_font((char *)&monobold12_data, monobold12_size);
125
126        seterrno(ENOENT);
127        return NULL;
128    }
129
130    if(size < sizeof(struct font_header))
131    {
132        debug("font error: data size %i < header size %i",
133              size, (int)sizeof(struct font_header));
134        seterrno(EINVAL);
135        return NULL;
136    }
137
138    f = malloc(sizeof(cucul_font_t));
139    if(!f)
140    {
141        seterrno(ENOMEM);
142        return NULL;
143    }
144
145    f->private = (void *)(uintptr_t)data;
146
147    memcpy(&f->header, f->private + 4, sizeof(struct font_header));
148    f->header.control_size = hton32(f->header.control_size);
149    f->header.data_size = hton32(f->header.data_size);
150    f->header.version = hton16(f->header.version);
151    f->header.blocks = hton16(f->header.blocks);
152    f->header.glyphs = hton32(f->header.glyphs);
153    f->header.bpp = hton16(f->header.bpp);
154    f->header.width = hton16(f->header.width);
155    f->header.height = hton16(f->header.height);
156    f->header.maxwidth = hton16(f->header.maxwidth);
157    f->header.maxheight = hton16(f->header.maxheight);
158    f->header.flags = hton16(f->header.flags);
159
160    if(size != 4 + f->header.control_size + f->header.data_size
161        || (f->header.bpp != 8 && f->header.bpp != 4 &&
162            f->header.bpp != 2 && f->header.bpp != 1)
163        || (f->header.flags & 1) == 0)
164    {
165#if defined DEBUG
166        if(size != 4 + f->header.control_size + f->header.data_size)
167            debug("font error: data size %i < expected size %i",
168                  size, 4 + f->header.control_size + f->header.data_size);
169        else if(f->header.bpp != 8 && f->header.bpp != 4 &&
170                f->header.bpp != 2 && f->header.bpp != 1)
171            debug("font error: invalid bpp %i", f->header.bpp);
172        else if((f->header.flags & 1) == 0)
173            debug("font error: invalid flags %.04x", f->header.flags);
174#endif
175        free(f);
176        seterrno(EINVAL);
177        return NULL;
178    }
179
180    f->block_list = malloc(f->header.blocks * sizeof(struct block_info));
181    if(!f->block_list)
182    {
183        free(f);
184        seterrno(ENOMEM);
185        return NULL;
186    }
187
188    f->user_block_list = malloc((f->header.blocks + 1)
189                                  * 2 * sizeof(uint32_t));
190    if(!f->user_block_list)
191    {
192        free(f->block_list);
193        free(f);
194        seterrno(ENOMEM);
195        return NULL;
196    }
197
198    memcpy(f->block_list,
199           f->private + 4 + sizeof(struct font_header),
200           f->header.blocks * sizeof(struct block_info));
201    for(i = 0; i < f->header.blocks; i++)
202    {
203        f->block_list[i].start = hton32(f->block_list[i].start);
204        f->block_list[i].stop = hton32(f->block_list[i].stop);
205        f->block_list[i].index = hton32(f->block_list[i].index);
206
207        if(f->block_list[i].start > f->block_list[i].stop
208            || (i > 0 && f->block_list[i].start < f->block_list[i - 1].stop)
209            || f->block_list[i].index >= f->header.glyphs)
210        {
211#if defined DEBUG
212            if(f->block_list[i].start > f->block_list[i].stop)
213                debug("font error: block %i has start %i > stop %i",
214                      i, f->block_list[i].start, f->block_list[i].stop);
215            else if(i > 0 && f->block_list[i].start < f->block_list[i - 1].stop)
216                debug("font error: block %i has start %i < previous stop %i",
217                      f->block_list[i].start, f->block_list[i - 1].stop);
218            else if(f->block_list[i].index >= f->header.glyphs)
219                debug("font error: block %i has index >= glyph count %i",
220                      f->block_list[i].index, f->header.glyphs);
221#endif
222            free(f->user_block_list);
223            free(f->block_list);
224            free(f);
225            seterrno(EINVAL);
226            return NULL;
227        }
228
229        f->user_block_list[i * 2] = f->block_list[i].start;
230        f->user_block_list[i * 2 + 1] = f->block_list[i].stop;
231    }
232
233    f->user_block_list[i * 2] = 0;
234    f->user_block_list[i * 2 + 1] = 0;
235
236    f->glyph_list = malloc(f->header.glyphs * sizeof(struct glyph_info));
237    if(!f->glyph_list)
238    {
239        free(f->user_block_list);
240        free(f->block_list);
241        free(f);
242        seterrno(ENOMEM);
243        return NULL;
244    }
245
246    memcpy(f->glyph_list,
247           f->private + 4 + sizeof(struct font_header)
248                + f->header.blocks * sizeof(struct block_info),
249           f->header.glyphs * sizeof(struct glyph_info));
250    for(i = 0; i < f->header.glyphs; i++)
251    {
252        f->glyph_list[i].width = hton16(f->glyph_list[i].width);
253        f->glyph_list[i].height = hton16(f->glyph_list[i].height);
254        f->glyph_list[i].data_offset = hton32(f->glyph_list[i].data_offset);
255
256        if(f->glyph_list[i].data_offset >= f->header.data_size
257            || f->glyph_list[i].data_offset
258                + (f->glyph_list[i].width * f->glyph_list[i].height *
259                   f->header.bpp + 7) / 8 > f->header.data_size
260            || f->glyph_list[i].width > f->header.maxwidth
261            || f->glyph_list[i].height > f->header.maxheight)
262        {
263#if defined DEBUG
264            if(f->glyph_list[i].data_offset >= f->header.data_size)
265                debug("font error: glyph %i has data start %i > "
266                      "data end %i",
267                      f->glyph_list[i].data_offset, f->header.data_size);
268            else if(f->glyph_list[i].data_offset
269                     + (f->glyph_list[i].width * f->glyph_list[i].height *
270                        f->header.bpp + 7) / 8 > f->header.data_size)
271                debug("font error: glyph %i has data end %i > "
272                      "data end %i", f->glyph_list[i].data_offset
273                       + (f->glyph_list[i].width * f->glyph_list[i].height *
274                          f->header.bpp + 7) / 8, f->header.data_size);
275            else if(f->glyph_list[i].width > f->header.maxwidth)
276                debug("font error: glyph %i has width %i > max width %i",
277                      f->glyph_list[i].width, f->header.maxwidth);
278            else if(f->glyph_list[i].height > f->header.maxheight)
279                debug("font error: glyph %i has height %i > max height %i",
280                      f->glyph_list[i].height, f->header.maxheight);
281#endif
282            free(f->glyph_list);
283            free(f->user_block_list);
284            free(f->block_list);
285            free(f);
286            seterrno(EINVAL);
287            return NULL;
288        }
289    }
290
291    f->font_data = f->private + 4 + f->header.control_size;
292
293    return f;
294}
295
296/** \brief Get available builtin fonts
297 *
298 *  Return a list of available builtin fonts. The list is a NULL-terminated
299 *  array of strings.
300 *
301 *  This function never fails.
302 *
303 *  \return An array of strings.
304 */
305char const * const * cucul_get_font_list(void)
306{
307    static char const * const list[] =
308    {
309        "Monospace 9",
310        "Monospace Bold 12",
311        NULL
312    };
313
314    return list;
315}
316
317/** \brief Get a font's standard glyph width.
318 *
319 *  Return the standard value for the current font's glyphs. Most glyphs in
320 *  the font will have this width, except fullwidth characters.
321 *
322 *  This function never fails.
323 *
324 *  \param f The font, as returned by cucul_load_font()
325 *  \return The standard glyph width.
326 */
327unsigned int cucul_get_font_width(cucul_font_t const *f)
328{
329    return f->header.width;
330}
331
332/** \brief Get a font's standard glyph height.
333 *
334 *  Returns the standard value for the current font's glyphs. Most glyphs in
335 *  the font will have this height.
336 *
337 *  This function never fails.
338 *
339 *  \param f The font, as returned by cucul_load_font()
340 *  \return The standard glyph height.
341 */
342unsigned int cucul_get_font_height(cucul_font_t const *f)
343{
344    return f->header.height;
345}
346
347/** \brief Get a font's list of supported glyphs.
348 *
349 *  This function returns the list of Unicode blocks supported by the
350 *  given font. The list is a zero-terminated list of indices. Here is
351 *  an example:
352 *
353 *  \code
354 *  {
355 *     0x0000, 0x0080,   // Basic latin: A, B, C, a, b, c
356 *     0x0080, 0x0100,   // Latin-1 supplement: "A, 'e, ^u
357 *     0x0530, 0x0590,   // Armenian
358 *     0x0000, 0x0000,   // END
359 *  };
360 *  \endcode
361 *
362 *  This function never fails.
363 *
364 *  \param f The font, as returned by cucul_load_font()
365 *  \return The list of Unicode blocks supported by the font.
366 */
367uint32_t const *cucul_get_font_blocks(cucul_font_t const *f)
368{
369    return (uint32_t const *)f->user_block_list;
370}
371
372/** \brief Free a font structure.
373 *
374 *  This function frees all data allocated by cucul_load_font(). The
375 *  font structure is no longer usable by other libcucul functions. Once
376 *  this function has returned, the memory area that was given to
377 *  cucul_load_font() can be freed.
378 *
379 *  This function never fails.
380 *
381 *  \param f The font, as returned by cucul_load_font()
382 *  \return This function always returns 0.
383 */
384int cucul_free_font(cucul_font_t *f)
385{
386    free(f->glyph_list);
387    free(f->user_block_list);
388    free(f->block_list);
389    free(f);
390
391    return 0;
392}
393
394/** \brief Render the canvas onto an image buffer.
395 *
396 *  This function renders the given canvas on an image buffer using a specific
397 *  font. The pixel format is fixed (32-bit ARGB, 8 bits for each component).
398 *
399 *  The required image width can be computed using
400 *  cucul_get_canvas_width() and cucul_get_font_width(). The required
401 *  height can be computed using cucul_get_canvas_height() and
402 *  cucul_get_font_height().
403 *
404 *  Glyphs that do not fit in the image buffer are currently not rendered at
405 *  all. They may be cropped instead in future versions.
406 *
407 *  This function never fails.
408 *
409 *  \param cv The canvas to render
410 *  \param f The font, as returned by cucul_load_font()
411 *  \param buf The image buffer
412 *  \param width The width (in pixels) of the image buffer
413 *  \param height The height (in pixels) of the image buffer
414 *  \param pitch The pitch (in bytes) of an image buffer line.
415 *  \return This function always returns 0.
416 */
417int cucul_render_canvas(cucul_canvas_t const *cv, cucul_font_t const *f,
418                        void *buf, unsigned int width,
419                        unsigned int height, unsigned int pitch)
420{
421    uint8_t *glyph = NULL;
422    unsigned int x, y, xmax, ymax;
423
424    if(f->header.bpp != 8)
425        glyph = malloc(f->header.width * 2 * f->header.height);
426
427    if(width < cv->width * f->header.width)
428        xmax = width / f->header.width;
429    else
430        xmax = cv->width;
431
432    if(height < cv->height * f->header.height)
433        ymax = height / f->header.height;
434    else
435        ymax = cv->height;
436
437    for(y = 0; y < ymax; y++)
438    {
439        for(x = 0; x < xmax; x++)
440        {
441            uint8_t argb[8];
442            unsigned int starty = y * f->header.height;
443            unsigned int startx = x * f->header.width;
444            uint32_t ch = cv->chars[y * cv->width + x];
445            uint32_t attr = cv->attrs[y * cv->width + x];
446            unsigned int b, i, j;
447            struct glyph_info *g;
448
449            /* Find the Unicode block where our glyph lies */
450            for(b = 0; b < f->header.blocks; b++)
451            {
452                if(ch < f->block_list[b].start)
453                {
454                    b = f->header.blocks;
455                    break;
456                }
457
458                if(ch < f->block_list[b].stop)
459                    break;
460            }
461
462            /* Glyph not in font? Skip it. */
463            if(b == f->header.blocks)
464                continue;
465
466            g = &f->glyph_list[f->block_list[b].index
467                                + ch - f->block_list[b].start];
468
469            cucul_attr_to_argb64(attr, argb);
470
471            /* Step 1: unpack glyph */
472            switch(f->header.bpp)
473            {
474            case 8:
475                glyph = f->font_data + g->data_offset;
476                break;
477            case 4:
478                unpack_glyph4(glyph, f->font_data + g->data_offset,
479                              g->width * g->height);
480                break;
481            case 2:
482                unpack_glyph2(glyph, f->font_data + g->data_offset,
483                              g->width * g->height);
484                break;
485            case 1:
486                unpack_glyph1(glyph, f->font_data + g->data_offset,
487                              g->width * g->height);
488                break;
489            }
490
491            /* Step 2: render glyph using colour attribute */
492            for(j = 0; j < g->height; j++)
493            {
494                uint8_t *line = buf;
495                line += (starty + j) * pitch + 4 * startx;
496
497                for(i = 0; i < g->width; i++)
498                {
499                    uint8_t *pixel = line + 4 * i;
500                    uint32_t p, q, t;
501
502                    p = glyph[j * g->width + i];
503                    q = 0xff - p;
504
505                    for(t = 0; t < 4; t++)
506                        pixel[t] = (((q * argb[t]) + (p * argb[4 + t])) / 0xf);
507                }
508            }
509        }
510    }
511
512    if(f->header.bpp != 8)
513        free(glyph);
514
515    return 0;
516}
517
Note: See TracBrowser for help on using the repository browser.