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[reactos.git] / lib / 3rdparty / freetype / src / sfnt / ttsbit.c
1 /***************************************************************************/
2 /* */
3 /* ttsbit.c */
4 /* */
5 /* TrueType and OpenType embedded bitmap support (body). */
6 /* */
7 /* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 by */
8 /* David Turner, Robert Wilhelm, and Werner Lemberg. */
9 /* */
10 /* This file is part of the FreeType project, and may only be used, */
11 /* modified, and distributed under the terms of the FreeType project */
12 /* license, LICENSE.TXT. By continuing to use, modify, or distribute */
13 /* this file you indicate that you have read the license and */
14 /* understand and accept it fully. */
15 /* */
16 /***************************************************************************/
17
18 #include <ft2build.h>
19 #include FT_INTERNAL_DEBUG_H
20 #include FT_INTERNAL_STREAM_H
21 #include FT_TRUETYPE_TAGS_H
22
23 /*
24 * Alas, the memory-optimized sbit loader can't be used when implementing
25 * the `old internals' hack
26 */
27 #ifndef FT_CONFIG_OPTION_OLD_INTERNALS
28
29 #include "ttsbit0.c"
30
31 #else /* FT_CONFIG_OPTION_OLD_INTERNALS */
32
33 #include <ft2build.h>
34 #include FT_INTERNAL_DEBUG_H
35 #include FT_INTERNAL_STREAM_H
36 #include FT_TRUETYPE_TAGS_H
37 #include "ttsbit.h"
38
39 #include "sferrors.h"
40
41
42 /*************************************************************************/
43 /* */
44 /* The macro FT_COMPONENT is used in trace mode. It is an implicit */
45 /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */
46 /* messages during execution. */
47 /* */
48 #undef FT_COMPONENT
49 #define FT_COMPONENT trace_ttsbit
50
51
52 /*************************************************************************/
53 /* */
54 /* <Function> */
55 /* blit_sbit */
56 /* */
57 /* <Description> */
58 /* Blits a bitmap from an input stream into a given target. Supports */
59 /* x and y offsets as well as byte padded lines. */
60 /* */
61 /* <Input> */
62 /* target :: The target bitmap/pixmap. */
63 /* */
64 /* source :: The input packed bitmap data. */
65 /* */
66 /* line_bits :: The number of bits per line. */
67 /* */
68 /* byte_padded :: A flag which is true if lines are byte-padded. */
69 /* */
70 /* x_offset :: The horizontal offset. */
71 /* */
72 /* y_offset :: The vertical offset. */
73 /* */
74 /* <Note> */
75 /* IMPORTANT: The x and y offsets are relative to the top corner of */
76 /* the target bitmap (unlike the normal TrueType */
77 /* convention). A positive y offset indicates a downwards */
78 /* direction! */
79 /* */
80 static void
81 blit_sbit( FT_Bitmap* target,
82 FT_Byte* source,
83 FT_Int line_bits,
84 FT_Bool byte_padded,
85 FT_Int x_offset,
86 FT_Int y_offset,
87 FT_Int source_height )
88 {
89 FT_Byte* line_buff;
90 FT_Int line_incr;
91 FT_Int height;
92
93 FT_UShort acc;
94 FT_UInt loaded;
95
96
97 /* first of all, compute starting write position */
98 line_incr = target->pitch;
99 line_buff = target->buffer;
100
101 if ( line_incr < 0 )
102 line_buff -= line_incr * ( target->rows - 1 );
103
104 line_buff += ( x_offset >> 3 ) + y_offset * line_incr;
105
106 /***********************************************************************/
107 /* */
108 /* We use the extra-classic `accumulator' trick to extract the bits */
109 /* from the source byte stream. */
110 /* */
111 /* Namely, the variable `acc' is a 16-bit accumulator containing the */
112 /* last `loaded' bits from the input stream. The bits are shifted to */
113 /* the upmost position in `acc'. */
114 /* */
115 /***********************************************************************/
116
117 acc = 0; /* clear accumulator */
118 loaded = 0; /* no bits were loaded */
119
120 for ( height = source_height; height > 0; height-- )
121 {
122 FT_Byte* cur = line_buff; /* current write cursor */
123 FT_Int count = line_bits; /* # of bits to extract per line */
124 FT_Byte shift = (FT_Byte)( x_offset & 7 ); /* current write shift */
125 FT_Byte space = (FT_Byte)( 8 - shift );
126
127
128 /* first of all, read individual source bytes */
129 if ( count >= 8 )
130 {
131 count -= 8;
132 {
133 do
134 {
135 FT_Byte val;
136
137
138 /* ensure that there are at least 8 bits in the accumulator */
139 if ( loaded < 8 )
140 {
141 acc |= (FT_UShort)((FT_UShort)*source++ << ( 8 - loaded ));
142 loaded += 8;
143 }
144
145 /* now write one byte */
146 val = (FT_Byte)( acc >> 8 );
147 if ( shift )
148 {
149 cur[0] |= (FT_Byte)( val >> shift );
150 cur[1] |= (FT_Byte)( val << space );
151 }
152 else
153 cur[0] |= val;
154
155 cur++;
156 acc <<= 8; /* remove bits from accumulator */
157 loaded -= 8;
158 count -= 8;
159
160 } while ( count >= 0 );
161 }
162
163 /* restore `count' to correct value */
164 count += 8;
165 }
166
167 /* now write remaining bits (count < 8) */
168 if ( count > 0 )
169 {
170 FT_Byte val;
171
172
173 /* ensure that there are at least `count' bits in the accumulator */
174 if ( (FT_Int)loaded < count )
175 {
176 acc |= (FT_UShort)((FT_UShort)*source++ << ( 8 - loaded ));
177 loaded += 8;
178 }
179
180 /* now write remaining bits */
181 val = (FT_Byte)( ( (FT_Byte)( acc >> 8 ) ) & ~( 0xFF >> count ) );
182 cur[0] |= (FT_Byte)( val >> shift );
183
184 if ( count > space )
185 cur[1] |= (FT_Byte)( val << space );
186
187 acc <<= count;
188 loaded -= count;
189 }
190
191 /* now, skip to next line */
192 if ( byte_padded )
193 {
194 acc = 0;
195 loaded = 0; /* clear accumulator on byte-padded lines */
196 }
197
198 line_buff += line_incr;
199 }
200 }
201
202
203 static const FT_Frame_Field sbit_metrics_fields[] =
204 {
205 #undef FT_STRUCTURE
206 #define FT_STRUCTURE TT_SBit_MetricsRec
207
208 FT_FRAME_START( 8 ),
209 FT_FRAME_BYTE( height ),
210 FT_FRAME_BYTE( width ),
211
212 FT_FRAME_CHAR( horiBearingX ),
213 FT_FRAME_CHAR( horiBearingY ),
214 FT_FRAME_BYTE( horiAdvance ),
215
216 FT_FRAME_CHAR( vertBearingX ),
217 FT_FRAME_CHAR( vertBearingY ),
218 FT_FRAME_BYTE( vertAdvance ),
219 FT_FRAME_END
220 };
221
222
223 /*************************************************************************/
224 /* */
225 /* <Function> */
226 /* Load_SBit_Const_Metrics */
227 /* */
228 /* <Description> */
229 /* Loads the metrics for `EBLC' index tables format 2 and 5. */
230 /* */
231 /* <Input> */
232 /* range :: The target range. */
233 /* */
234 /* stream :: The input stream. */
235 /* */
236 /* <Return> */
237 /* FreeType error code. 0 means success. */
238 /* */
239 static FT_Error
240 Load_SBit_Const_Metrics( TT_SBit_Range range,
241 FT_Stream stream )
242 {
243 FT_Error error;
244
245
246 if ( FT_READ_ULONG( range->image_size ) )
247 return error;
248
249 return FT_STREAM_READ_FIELDS( sbit_metrics_fields, &range->metrics );
250 }
251
252
253 /*************************************************************************/
254 /* */
255 /* <Function> */
256 /* Load_SBit_Range_Codes */
257 /* */
258 /* <Description> */
259 /* Loads the range codes for `EBLC' index tables format 4 and 5. */
260 /* */
261 /* <Input> */
262 /* range :: The target range. */
263 /* */
264 /* stream :: The input stream. */
265 /* */
266 /* load_offsets :: A flag whether to load the glyph offset table. */
267 /* */
268 /* <Return> */
269 /* FreeType error code. 0 means success. */
270 /* */
271 static FT_Error
272 Load_SBit_Range_Codes( TT_SBit_Range range,
273 FT_Stream stream,
274 FT_Bool load_offsets )
275 {
276 FT_Error error;
277 FT_ULong count, n, size;
278 FT_Memory memory = stream->memory;
279
280
281 if ( FT_READ_ULONG( count ) )
282 goto Exit;
283
284 range->num_glyphs = count;
285
286 /* Allocate glyph offsets table if needed */
287 if ( load_offsets )
288 {
289 if ( FT_NEW_ARRAY( range->glyph_offsets, count ) )
290 goto Exit;
291
292 size = count * 4L;
293 }
294 else
295 size = count * 2L;
296
297 /* Allocate glyph codes table and access frame */
298 if ( FT_NEW_ARRAY ( range->glyph_codes, count ) ||
299 FT_FRAME_ENTER( size ) )
300 goto Exit;
301
302 for ( n = 0; n < count; n++ )
303 {
304 range->glyph_codes[n] = FT_GET_USHORT();
305
306 if ( load_offsets )
307 range->glyph_offsets[n] = (FT_ULong)range->image_offset +
308 FT_GET_USHORT();
309 }
310
311 FT_FRAME_EXIT();
312
313 Exit:
314 return error;
315 }
316
317
318 /*************************************************************************/
319 /* */
320 /* <Function> */
321 /* Load_SBit_Range */
322 /* */
323 /* <Description> */
324 /* Loads a given `EBLC' index/range table. */
325 /* */
326 /* <Input> */
327 /* range :: The target range. */
328 /* */
329 /* stream :: The input stream. */
330 /* */
331 /* <Return> */
332 /* FreeType error code. 0 means success. */
333 /* */
334 static FT_Error
335 Load_SBit_Range( TT_SBit_Range range,
336 FT_Stream stream )
337 {
338 FT_Error error;
339 FT_Memory memory = stream->memory;
340
341
342 switch( range->index_format )
343 {
344 case 1: /* variable metrics with 4-byte offsets */
345 case 3: /* variable metrics with 2-byte offsets */
346 {
347 FT_ULong num_glyphs, n;
348 FT_Int size_elem;
349 FT_Bool large = FT_BOOL( range->index_format == 1 );
350
351
352
353 if ( range->last_glyph < range->first_glyph )
354 {
355 error = SFNT_Err_Invalid_File_Format;
356 goto Exit;
357 }
358
359 num_glyphs = range->last_glyph - range->first_glyph + 1L;
360 range->num_glyphs = num_glyphs;
361 num_glyphs++; /* XXX: BEWARE - see spec */
362
363 size_elem = large ? 4 : 2;
364
365 if ( FT_NEW_ARRAY( range->glyph_offsets, num_glyphs ) ||
366 FT_FRAME_ENTER( num_glyphs * size_elem ) )
367 goto Exit;
368
369 for ( n = 0; n < num_glyphs; n++ )
370 range->glyph_offsets[n] = (FT_ULong)( range->image_offset +
371 ( large ? FT_GET_ULONG()
372 : FT_GET_USHORT() ) );
373 FT_FRAME_EXIT();
374 }
375 break;
376
377 case 2: /* all glyphs have identical metrics */
378 error = Load_SBit_Const_Metrics( range, stream );
379 break;
380
381 case 4:
382 error = Load_SBit_Range_Codes( range, stream, 1 );
383 break;
384
385 case 5:
386 error = Load_SBit_Const_Metrics( range, stream );
387 if ( !error )
388 error = Load_SBit_Range_Codes( range, stream, 0 );
389 break;
390
391 default:
392 error = SFNT_Err_Invalid_File_Format;
393 }
394
395 Exit:
396 return error;
397 }
398
399
400 /*************************************************************************/
401 /* */
402 /* <Function> */
403 /* tt_face_load_eblc */
404 /* */
405 /* <Description> */
406 /* Loads the table of embedded bitmap sizes for this face. */
407 /* */
408 /* <Input> */
409 /* face :: The target face object. */
410 /* */
411 /* stream :: The input stream. */
412 /* */
413 /* <Return> */
414 /* FreeType error code. 0 means success. */
415 /* */
416 FT_LOCAL_DEF( FT_Error )
417 tt_face_load_eblc( TT_Face face,
418 FT_Stream stream )
419 {
420 FT_Error error = 0;
421 FT_Memory memory = stream->memory;
422 FT_Fixed version;
423 FT_ULong num_strikes;
424 FT_ULong table_base;
425
426 static const FT_Frame_Field sbit_line_metrics_fields[] =
427 {
428 #undef FT_STRUCTURE
429 #define FT_STRUCTURE TT_SBit_LineMetricsRec
430
431 /* no FT_FRAME_START */
432 FT_FRAME_CHAR( ascender ),
433 FT_FRAME_CHAR( descender ),
434 FT_FRAME_BYTE( max_width ),
435
436 FT_FRAME_CHAR( caret_slope_numerator ),
437 FT_FRAME_CHAR( caret_slope_denominator ),
438 FT_FRAME_CHAR( caret_offset ),
439
440 FT_FRAME_CHAR( min_origin_SB ),
441 FT_FRAME_CHAR( min_advance_SB ),
442 FT_FRAME_CHAR( max_before_BL ),
443 FT_FRAME_CHAR( min_after_BL ),
444 FT_FRAME_CHAR( pads[0] ),
445 FT_FRAME_CHAR( pads[1] ),
446 FT_FRAME_END
447 };
448
449 static const FT_Frame_Field strike_start_fields[] =
450 {
451 #undef FT_STRUCTURE
452 #define FT_STRUCTURE TT_SBit_StrikeRec
453
454 /* no FT_FRAME_START */
455 FT_FRAME_ULONG( ranges_offset ),
456 FT_FRAME_SKIP_LONG,
457 FT_FRAME_ULONG( num_ranges ),
458 FT_FRAME_ULONG( color_ref ),
459 FT_FRAME_END
460 };
461
462 static const FT_Frame_Field strike_end_fields[] =
463 {
464 /* no FT_FRAME_START */
465 FT_FRAME_USHORT( start_glyph ),
466 FT_FRAME_USHORT( end_glyph ),
467 FT_FRAME_BYTE ( x_ppem ),
468 FT_FRAME_BYTE ( y_ppem ),
469 FT_FRAME_BYTE ( bit_depth ),
470 FT_FRAME_CHAR ( flags ),
471 FT_FRAME_END
472 };
473
474
475 face->num_sbit_strikes = 0;
476
477 /* this table is optional */
478 error = face->goto_table( face, TTAG_EBLC, stream, 0 );
479 if ( error )
480 error = face->goto_table( face, TTAG_bloc, stream, 0 );
481 if ( error )
482 goto Exit;
483
484 table_base = FT_STREAM_POS();
485 if ( FT_FRAME_ENTER( 8L ) )
486 goto Exit;
487
488 version = FT_GET_LONG();
489 num_strikes = FT_GET_ULONG();
490
491 FT_FRAME_EXIT();
492
493 /* check version number and strike count */
494 if ( version != 0x00020000L ||
495 num_strikes >= 0x10000L )
496 {
497 FT_ERROR(( "tt_face_load_sbit_strikes: invalid table version\n" ));
498 error = SFNT_Err_Invalid_File_Format;
499
500 goto Exit;
501 }
502
503 /* allocate the strikes table */
504 if ( FT_NEW_ARRAY( face->sbit_strikes, num_strikes ) )
505 goto Exit;
506
507 face->num_sbit_strikes = num_strikes;
508
509 /* now read each strike table separately */
510 {
511 TT_SBit_Strike strike = face->sbit_strikes;
512 FT_ULong count = num_strikes;
513
514
515 if ( FT_FRAME_ENTER( 48L * num_strikes ) )
516 goto Exit;
517
518 while ( count > 0 )
519 {
520 if ( FT_STREAM_READ_FIELDS( strike_start_fields, strike ) ||
521 FT_STREAM_READ_FIELDS( sbit_line_metrics_fields, &strike->hori ) ||
522 FT_STREAM_READ_FIELDS( sbit_line_metrics_fields, &strike->vert ) ||
523 FT_STREAM_READ_FIELDS( strike_end_fields, strike ) )
524 break;
525
526 count--;
527 strike++;
528 }
529
530 FT_FRAME_EXIT();
531 }
532
533 /* allocate the index ranges for each strike table */
534 {
535 TT_SBit_Strike strike = face->sbit_strikes;
536 FT_ULong count = num_strikes;
537
538
539 while ( count > 0 )
540 {
541 TT_SBit_Range range;
542 FT_ULong count2 = strike->num_ranges;
543
544
545 /* read each range */
546 if ( FT_STREAM_SEEK( table_base + strike->ranges_offset ) ||
547 FT_FRAME_ENTER( strike->num_ranges * 8L ) )
548 goto Exit;
549
550 if ( FT_NEW_ARRAY( strike->sbit_ranges, strike->num_ranges ) )
551 goto Exit;
552
553 range = strike->sbit_ranges;
554 while ( count2 > 0 )
555 {
556 range->first_glyph = FT_GET_USHORT();
557 range->last_glyph = FT_GET_USHORT();
558 range->table_offset = table_base + strike->ranges_offset +
559 FT_GET_ULONG();
560 count2--;
561 range++;
562 }
563
564 FT_FRAME_EXIT();
565
566 /* Now, read each index table */
567 count2 = strike->num_ranges;
568 range = strike->sbit_ranges;
569 while ( count2 > 0 )
570 {
571 /* Read the header */
572 if ( FT_STREAM_SEEK( range->table_offset ) ||
573 FT_FRAME_ENTER( 8L ) )
574 goto Exit;
575
576 range->index_format = FT_GET_USHORT();
577 range->image_format = FT_GET_USHORT();
578 range->image_offset = FT_GET_ULONG();
579
580 FT_FRAME_EXIT();
581
582 error = Load_SBit_Range( range, stream );
583 if ( error )
584 goto Exit;
585
586 count2--;
587 range++;
588 }
589
590 count--;
591 strike++;
592 }
593 }
594
595 Exit:
596 return error;
597 }
598
599
600 /*************************************************************************/
601 /* */
602 /* <Function> */
603 /* tt_face_free_eblc */
604 /* */
605 /* <Description> */
606 /* Releases the embedded bitmap tables. */
607 /* */
608 /* <Input> */
609 /* face :: The target face object. */
610 /* */
611 FT_LOCAL_DEF( void )
612 tt_face_free_eblc( TT_Face face )
613 {
614 FT_Memory memory = face->root.memory;
615 TT_SBit_Strike strike = face->sbit_strikes;
616 TT_SBit_Strike strike_limit = strike + face->num_sbit_strikes;
617
618
619 if ( strike )
620 {
621 for ( ; strike < strike_limit; strike++ )
622 {
623 TT_SBit_Range range = strike->sbit_ranges;
624 TT_SBit_Range range_limit = range + strike->num_ranges;
625
626
627 if ( range )
628 {
629 for ( ; range < range_limit; range++ )
630 {
631 /* release the glyph offsets and codes tables */
632 /* where appropriate */
633 FT_FREE( range->glyph_offsets );
634 FT_FREE( range->glyph_codes );
635 }
636 }
637 FT_FREE( strike->sbit_ranges );
638 strike->num_ranges = 0;
639 }
640 FT_FREE( face->sbit_strikes );
641 }
642 face->num_sbit_strikes = 0;
643 }
644
645
646 FT_LOCAL_DEF( FT_Error )
647 tt_face_set_sbit_strike( TT_Face face,
648 FT_Size_Request req,
649 FT_ULong* astrike_index )
650 {
651 return FT_Match_Size( (FT_Face)face, req, 0, astrike_index );
652 }
653
654
655 FT_LOCAL_DEF( FT_Error )
656 tt_face_load_strike_metrics( TT_Face face,
657 FT_ULong strike_index,
658 FT_Size_Metrics* metrics )
659 {
660 TT_SBit_Strike strike;
661
662
663 if ( strike_index >= face->num_sbit_strikes )
664 return SFNT_Err_Invalid_Argument;
665
666 strike = face->sbit_strikes + strike_index;
667
668 metrics->x_ppem = strike->x_ppem;
669 metrics->y_ppem = strike->y_ppem;
670
671 metrics->ascender = strike->hori.ascender << 6;
672 metrics->descender = strike->hori.descender << 6;
673
674 /* XXX: Is this correct? */
675 metrics->max_advance = ( strike->hori.min_origin_SB +
676 strike->hori.max_width +
677 strike->hori.min_advance_SB ) << 6;
678
679 metrics->height = metrics->ascender - metrics->descender;
680
681 return SFNT_Err_Ok;
682 }
683
684
685 /*************************************************************************/
686 /* */
687 /* <Function> */
688 /* find_sbit_range */
689 /* */
690 /* <Description> */
691 /* Scans a given strike's ranges and return, for a given glyph */
692 /* index, the corresponding sbit range, and `EBDT' offset. */
693 /* */
694 /* <Input> */
695 /* glyph_index :: The glyph index. */
696 /* */
697 /* strike :: The source/current sbit strike. */
698 /* */
699 /* <Output> */
700 /* arange :: The sbit range containing the glyph index. */
701 /* */
702 /* aglyph_offset :: The offset of the glyph data in `EBDT' table. */
703 /* */
704 /* <Return> */
705 /* FreeType error code. 0 means the glyph index was found. */
706 /* */
707 static FT_Error
708 find_sbit_range( FT_UInt glyph_index,
709 TT_SBit_Strike strike,
710 TT_SBit_Range *arange,
711 FT_ULong *aglyph_offset )
712 {
713 TT_SBit_RangeRec *range, *range_limit;
714
715
716 /* check whether the glyph index is within this strike's */
717 /* glyph range */
718 if ( glyph_index < (FT_UInt)strike->start_glyph ||
719 glyph_index > (FT_UInt)strike->end_glyph )
720 goto Fail;
721
722 /* scan all ranges in strike */
723 range = strike->sbit_ranges;
724 range_limit = range + strike->num_ranges;
725 if ( !range )
726 goto Fail;
727
728 for ( ; range < range_limit; range++ )
729 {
730 if ( glyph_index >= (FT_UInt)range->first_glyph &&
731 glyph_index <= (FT_UInt)range->last_glyph )
732 {
733 FT_UShort delta = (FT_UShort)( glyph_index - range->first_glyph );
734
735
736 switch ( range->index_format )
737 {
738 case 1:
739 case 3:
740 *aglyph_offset = range->glyph_offsets[delta];
741 break;
742
743 case 2:
744 *aglyph_offset = range->image_offset +
745 range->image_size * delta;
746 break;
747
748 case 4:
749 case 5:
750 {
751 FT_ULong n;
752
753
754 for ( n = 0; n < range->num_glyphs; n++ )
755 {
756 if ( (FT_UInt)range->glyph_codes[n] == glyph_index )
757 {
758 if ( range->index_format == 4 )
759 *aglyph_offset = range->glyph_offsets[n];
760 else
761 *aglyph_offset = range->image_offset +
762 n * range->image_size;
763 goto Found;
764 }
765 }
766 }
767
768 /* fall-through */
769 default:
770 goto Fail;
771 }
772
773 Found:
774 /* return successfully! */
775 *arange = range;
776 return SFNT_Err_Ok;
777 }
778 }
779
780 Fail:
781 *arange = 0;
782 *aglyph_offset = 0;
783
784 return SFNT_Err_Invalid_Argument;
785 }
786
787
788 /*************************************************************************/
789 /* */
790 /* <Function> */
791 /* tt_find_sbit_image */
792 /* */
793 /* <Description> */
794 /* Checks whether an embedded bitmap (an `sbit') exists for a given */
795 /* glyph, at a given strike. */
796 /* */
797 /* <Input> */
798 /* face :: The target face object. */
799 /* */
800 /* glyph_index :: The glyph index. */
801 /* */
802 /* strike_index :: The current strike index. */
803 /* */
804 /* <Output> */
805 /* arange :: The SBit range containing the glyph index. */
806 /* */
807 /* astrike :: The SBit strike containing the glyph index. */
808 /* */
809 /* aglyph_offset :: The offset of the glyph data in `EBDT' table. */
810 /* */
811 /* <Return> */
812 /* FreeType error code. 0 means success. Returns */
813 /* SFNT_Err_Invalid_Argument if no sbit exists for the requested */
814 /* glyph. */
815 /* */
816 FT_LOCAL( FT_Error )
817 tt_find_sbit_image( TT_Face face,
818 FT_UInt glyph_index,
819 FT_ULong strike_index,
820 TT_SBit_Range *arange,
821 TT_SBit_Strike *astrike,
822 FT_ULong *aglyph_offset )
823 {
824 FT_Error error;
825 TT_SBit_Strike strike;
826
827
828 if ( !face->sbit_strikes ||
829 ( face->num_sbit_strikes <= strike_index ) )
830 goto Fail;
831
832 strike = &face->sbit_strikes[strike_index];
833
834 error = find_sbit_range( glyph_index, strike,
835 arange, aglyph_offset );
836 if ( error )
837 goto Fail;
838
839 *astrike = strike;
840
841 return SFNT_Err_Ok;
842
843 Fail:
844 /* no embedded bitmap for this glyph in face */
845 *arange = 0;
846 *astrike = 0;
847 *aglyph_offset = 0;
848
849 return SFNT_Err_Invalid_Argument;
850 }
851
852
853 /*************************************************************************/
854 /* */
855 /* <Function> */
856 /* tt_load_sbit_metrics */
857 /* */
858 /* <Description> */
859 /* Gets the big metrics for a given SBit. */
860 /* */
861 /* <Input> */
862 /* stream :: The input stream. */
863 /* */
864 /* range :: The SBit range containing the glyph. */
865 /* */
866 /* <Output> */
867 /* big_metrics :: A big SBit metrics structure for the glyph. */
868 /* */
869 /* <Return> */
870 /* FreeType error code. 0 means success. */
871 /* */
872 /* <Note> */
873 /* The stream cursor must be positioned at the glyph's offset within */
874 /* the `EBDT' table before the call. */
875 /* */
876 /* If the image format uses variable metrics, the stream cursor is */
877 /* positioned just after the metrics header in the `EBDT' table on */
878 /* function exit. */
879 /* */
880 FT_LOCAL( FT_Error )
881 tt_load_sbit_metrics( FT_Stream stream,
882 TT_SBit_Range range,
883 TT_SBit_Metrics metrics )
884 {
885 FT_Error error = SFNT_Err_Ok;
886
887
888 switch ( range->image_format )
889 {
890 case 1:
891 case 2:
892 case 8:
893 /* variable small metrics */
894 {
895 TT_SBit_SmallMetricsRec smetrics;
896
897 static const FT_Frame_Field sbit_small_metrics_fields[] =
898 {
899 #undef FT_STRUCTURE
900 #define FT_STRUCTURE TT_SBit_SmallMetricsRec
901
902 FT_FRAME_START( 5 ),
903 FT_FRAME_BYTE( height ),
904 FT_FRAME_BYTE( width ),
905 FT_FRAME_CHAR( bearingX ),
906 FT_FRAME_CHAR( bearingY ),
907 FT_FRAME_BYTE( advance ),
908 FT_FRAME_END
909 };
910
911
912 /* read small metrics */
913 if ( FT_STREAM_READ_FIELDS( sbit_small_metrics_fields, &smetrics ) )
914 goto Exit;
915
916 /* convert it to a big metrics */
917 metrics->height = smetrics.height;
918 metrics->width = smetrics.width;
919 metrics->horiBearingX = smetrics.bearingX;
920 metrics->horiBearingY = smetrics.bearingY;
921 metrics->horiAdvance = smetrics.advance;
922
923 /* these metrics are made up at a higher level when */
924 /* needed. */
925 metrics->vertBearingX = 0;
926 metrics->vertBearingY = 0;
927 metrics->vertAdvance = 0;
928 }
929 break;
930
931 case 6:
932 case 7:
933 case 9:
934 /* variable big metrics */
935 if ( FT_STREAM_READ_FIELDS( sbit_metrics_fields, metrics ) )
936 goto Exit;
937 break;
938
939 case 5:
940 default: /* constant metrics */
941 if ( range->index_format == 2 || range->index_format == 5 )
942 *metrics = range->metrics;
943 else
944 return SFNT_Err_Invalid_File_Format;
945 }
946
947 Exit:
948 return error;
949 }
950
951
952 /*************************************************************************/
953 /* */
954 /* <Function> */
955 /* crop_bitmap */
956 /* */
957 /* <Description> */
958 /* Crops a bitmap to its tightest bounding box, and adjusts its */
959 /* metrics. */
960 /* */
961 /* <InOut> */
962 /* map :: The bitmap. */
963 /* */
964 /* metrics :: The corresponding metrics structure. */
965 /* */
966 static void
967 crop_bitmap( FT_Bitmap* map,
968 TT_SBit_Metrics metrics )
969 {
970 /***********************************************************************/
971 /* */
972 /* In this situation, some bounding boxes of embedded bitmaps are too */
973 /* large. We need to crop it to a reasonable size. */
974 /* */
975 /* --------- */
976 /* | | ----- */
977 /* | *** | |***| */
978 /* | * | | * | */
979 /* | * | ------> | * | */
980 /* | * | | * | */
981 /* | * | | * | */
982 /* | *** | |***| */
983 /* --------- ----- */
984 /* */
985 /***********************************************************************/
986
987 FT_Int rows, count;
988 FT_Long line_len;
989 FT_Byte* line;
990
991
992 /***********************************************************************/
993 /* */
994 /* first of all, check the top-most lines of the bitmap, and remove */
995 /* them if they're empty. */
996 /* */
997 {
998 line = (FT_Byte*)map->buffer;
999 rows = map->rows;
1000 line_len = map->pitch;
1001
1002
1003 for ( count = 0; count < rows; count++ )
1004 {
1005 FT_Byte* cur = line;
1006 FT_Byte* limit = line + line_len;
1007
1008
1009 for ( ; cur < limit; cur++ )
1010 if ( cur[0] )
1011 goto Found_Top;
1012
1013 /* the current line was empty - skip to next one */
1014 line = limit;
1015 }
1016
1017 Found_Top:
1018 /* check that we have at least one filled line */
1019 if ( count >= rows )
1020 goto Empty_Bitmap;
1021
1022 /* now, crop the empty upper lines */
1023 if ( count > 0 )
1024 {
1025 line = (FT_Byte*)map->buffer;
1026
1027 FT_MEM_MOVE( line, line + count * line_len,
1028 ( rows - count ) * line_len );
1029
1030 metrics->height = (FT_Byte)( metrics->height - count );
1031 metrics->horiBearingY = (FT_Char)( metrics->horiBearingY - count );
1032 metrics->vertBearingY = (FT_Char)( metrics->vertBearingY - count );
1033
1034 map->rows -= count;
1035 rows -= count;
1036 }
1037 }
1038
1039 /***********************************************************************/
1040 /* */
1041 /* second, crop the lower lines */
1042 /* */
1043 {
1044 line = (FT_Byte*)map->buffer + ( rows - 1 ) * line_len;
1045
1046 for ( count = 0; count < rows; count++ )
1047 {
1048 FT_Byte* cur = line;
1049 FT_Byte* limit = line + line_len;
1050
1051
1052 for ( ; cur < limit; cur++ )
1053 if ( cur[0] )
1054 goto Found_Bottom;
1055
1056 /* the current line was empty - skip to previous one */
1057 line -= line_len;
1058 }
1059
1060 Found_Bottom:
1061 if ( count > 0 )
1062 {
1063 metrics->height = (FT_Byte)( metrics->height - count );
1064 rows -= count;
1065 map->rows -= count;
1066 }
1067 }
1068
1069 /***********************************************************************/
1070 /* */
1071 /* third, get rid of the space on the left side of the glyph */
1072 /* */
1073 do
1074 {
1075 FT_Byte* limit;
1076
1077
1078 line = (FT_Byte*)map->buffer;
1079 limit = line + rows * line_len;
1080
1081 for ( ; line < limit; line += line_len )
1082 if ( line[0] & 0x80 )
1083 goto Found_Left;
1084
1085 /* shift the whole glyph one pixel to the left */
1086 line = (FT_Byte*)map->buffer;
1087 limit = line + rows * line_len;
1088
1089 for ( ; line < limit; line += line_len )
1090 {
1091 FT_Int n, width = map->width;
1092 FT_Byte old;
1093 FT_Byte* cur = line;
1094
1095
1096 old = (FT_Byte)(cur[0] << 1);
1097 for ( n = 8; n < width; n += 8 )
1098 {
1099 FT_Byte val;
1100
1101
1102 val = cur[1];
1103 cur[0] = (FT_Byte)( old | ( val >> 7 ) );
1104 old = (FT_Byte)( val << 1 );
1105 cur++;
1106 }
1107 cur[0] = old;
1108 }
1109
1110 map->width--;
1111 metrics->horiBearingX++;
1112 metrics->vertBearingX++;
1113 metrics->width--;
1114
1115 } while ( map->width > 0 );
1116
1117 Found_Left:
1118
1119 /***********************************************************************/
1120 /* */
1121 /* finally, crop the bitmap width to get rid of the space on the right */
1122 /* side of the glyph. */
1123 /* */
1124 do
1125 {
1126 FT_Int right = map->width - 1;
1127 FT_Byte* limit;
1128 FT_Byte mask;
1129
1130
1131 line = (FT_Byte*)map->buffer + ( right >> 3 );
1132 limit = line + rows * line_len;
1133 mask = (FT_Byte)( 0x80 >> ( right & 7 ) );
1134
1135 for ( ; line < limit; line += line_len )
1136 if ( line[0] & mask )
1137 goto Found_Right;
1138
1139 /* crop the whole glyph to the right */
1140 map->width--;
1141 metrics->width--;
1142
1143 } while ( map->width > 0 );
1144
1145 Found_Right:
1146 /* all right, the bitmap was cropped */
1147 return;
1148
1149 Empty_Bitmap:
1150 map->width = 0;
1151 map->rows = 0;
1152 map->pitch = 0;
1153 map->pixel_mode = FT_PIXEL_MODE_MONO;
1154 }
1155
1156
1157 static FT_Error
1158 Load_SBit_Single( FT_Bitmap* map,
1159 FT_Int x_offset,
1160 FT_Int y_offset,
1161 FT_Int pix_bits,
1162 FT_UShort image_format,
1163 TT_SBit_Metrics metrics,
1164 FT_Stream stream )
1165 {
1166 FT_Error error;
1167
1168
1169 /* check that the source bitmap fits into the target pixmap */
1170 if ( x_offset < 0 || x_offset + metrics->width > map->width ||
1171 y_offset < 0 || y_offset + metrics->height > map->rows )
1172 {
1173 error = SFNT_Err_Invalid_Argument;
1174
1175 goto Exit;
1176 }
1177
1178 {
1179 FT_Int glyph_width = metrics->width;
1180 FT_Int glyph_height = metrics->height;
1181 FT_Int glyph_size;
1182 FT_Int line_bits = pix_bits * glyph_width;
1183 FT_Bool pad_bytes = 0;
1184
1185
1186 /* compute size of glyph image */
1187 switch ( image_format )
1188 {
1189 case 1: /* byte-padded formats */
1190 case 6:
1191 {
1192 FT_Int line_length;
1193
1194
1195 switch ( pix_bits )
1196 {
1197 case 1:
1198 line_length = ( glyph_width + 7 ) >> 3;
1199 break;
1200 case 2:
1201 line_length = ( glyph_width + 3 ) >> 2;
1202 break;
1203 case 4:
1204 line_length = ( glyph_width + 1 ) >> 1;
1205 break;
1206 default:
1207 line_length = glyph_width;
1208 }
1209
1210 glyph_size = glyph_height * line_length;
1211 pad_bytes = 1;
1212 }
1213 break;
1214
1215 case 2:
1216 case 5:
1217 case 7:
1218 line_bits = glyph_width * pix_bits;
1219 glyph_size = ( glyph_height * line_bits + 7 ) >> 3;
1220 break;
1221
1222 default: /* invalid format */
1223 return SFNT_Err_Invalid_File_Format;
1224 }
1225
1226 /* Now read data and draw glyph into target pixmap */
1227 if ( FT_FRAME_ENTER( glyph_size ) )
1228 goto Exit;
1229
1230 /* don't forget to multiply `x_offset' by `map->pix_bits' as */
1231 /* the sbit blitter doesn't make a difference between pixmap */
1232 /* depths. */
1233 blit_sbit( map, (FT_Byte*)stream->cursor, line_bits, pad_bytes,
1234 x_offset * pix_bits, y_offset, metrics->height );
1235
1236 FT_FRAME_EXIT();
1237 }
1238
1239 Exit:
1240 return error;
1241 }
1242
1243
1244 static FT_Error
1245 Load_SBit_Image( TT_SBit_Strike strike,
1246 TT_SBit_Range range,
1247 FT_ULong ebdt_pos,
1248 FT_ULong glyph_offset,
1249 FT_GlyphSlot slot,
1250 FT_Int x_offset,
1251 FT_Int y_offset,
1252 FT_Stream stream,
1253 TT_SBit_Metrics metrics,
1254 FT_Int depth )
1255 {
1256 FT_Memory memory = stream->memory;
1257 FT_Bitmap* map = &slot->bitmap;
1258 FT_Error error;
1259
1260
1261 /* place stream at beginning of glyph data and read metrics */
1262 if ( FT_STREAM_SEEK( ebdt_pos + glyph_offset ) )
1263 goto Exit;
1264
1265 error = tt_load_sbit_metrics( stream, range, metrics );
1266 if ( error )
1267 goto Exit;
1268
1269 /* This function is recursive. At the top-level call, we */
1270 /* compute the dimensions of the higher-level glyph to */
1271 /* allocate the final pixmap buffer. */
1272 if ( depth == 0 )
1273 {
1274 FT_Long size;
1275
1276
1277 map->width = metrics->width;
1278 map->rows = metrics->height;
1279
1280 switch ( strike->bit_depth )
1281 {
1282 case 1:
1283 map->pixel_mode = FT_PIXEL_MODE_MONO;
1284 map->pitch = ( map->width + 7 ) >> 3;
1285 break;
1286
1287 case 2:
1288 map->pixel_mode = FT_PIXEL_MODE_GRAY2;
1289 map->pitch = ( map->width + 3 ) >> 2;
1290 break;
1291
1292 case 4:
1293 map->pixel_mode = FT_PIXEL_MODE_GRAY4;
1294 map->pitch = ( map->width + 1 ) >> 1;
1295 break;
1296
1297 case 8:
1298 map->pixel_mode = FT_PIXEL_MODE_GRAY;
1299 map->pitch = map->width;
1300 break;
1301
1302 default:
1303 return SFNT_Err_Invalid_File_Format;
1304 }
1305
1306 size = map->rows * map->pitch;
1307
1308 /* check that there is no empty image */
1309 if ( size == 0 )
1310 goto Exit; /* exit successfully! */
1311
1312 error = ft_glyphslot_alloc_bitmap( slot, size );
1313 if (error)
1314 goto Exit;
1315 }
1316
1317 switch ( range->image_format )
1318 {
1319 case 1: /* single sbit image - load it */
1320 case 2:
1321 case 5:
1322 case 6:
1323 case 7:
1324 return Load_SBit_Single( map, x_offset, y_offset, strike->bit_depth,
1325 range->image_format, metrics, stream );
1326
1327 case 8: /* compound format */
1328 if ( FT_STREAM_SKIP( 1L ) )
1329 {
1330 error = SFNT_Err_Invalid_Stream_Skip;
1331 goto Exit;
1332 }
1333 /* fallthrough */
1334
1335 case 9:
1336 break;
1337
1338 default: /* invalid image format */
1339 return SFNT_Err_Invalid_File_Format;
1340 }
1341
1342 /* All right, we have a compound format. First of all, read */
1343 /* the array of elements. */
1344 {
1345 TT_SBit_Component components;
1346 TT_SBit_Component comp;
1347 FT_UShort num_components, count;
1348
1349
1350 if ( FT_READ_USHORT( num_components ) ||
1351 FT_NEW_ARRAY( components, num_components ) )
1352 goto Exit;
1353
1354 count = num_components;
1355
1356 if ( FT_FRAME_ENTER( 4L * num_components ) )
1357 goto Fail_Memory;
1358
1359 for ( comp = components; count > 0; count--, comp++ )
1360 {
1361 comp->glyph_code = FT_GET_USHORT();
1362 comp->x_offset = FT_GET_CHAR();
1363 comp->y_offset = FT_GET_CHAR();
1364 }
1365
1366 FT_FRAME_EXIT();
1367
1368 /* Now recursively load each element glyph */
1369 count = num_components;
1370 comp = components;
1371 for ( ; count > 0; count--, comp++ )
1372 {
1373 TT_SBit_Range elem_range;
1374 TT_SBit_MetricsRec elem_metrics;
1375 FT_ULong elem_offset;
1376
1377
1378 /* find the range for this element */
1379 error = find_sbit_range( comp->glyph_code,
1380 strike,
1381 &elem_range,
1382 &elem_offset );
1383 if ( error )
1384 goto Fail_Memory;
1385
1386 /* now load the element, recursively */
1387 error = Load_SBit_Image( strike,
1388 elem_range,
1389 ebdt_pos,
1390 elem_offset,
1391 slot,
1392 x_offset + comp->x_offset,
1393 y_offset + comp->y_offset,
1394 stream,
1395 &elem_metrics,
1396 depth + 1 );
1397 if ( error )
1398 goto Fail_Memory;
1399 }
1400
1401 Fail_Memory:
1402 FT_FREE( components );
1403 }
1404
1405 Exit:
1406 return error;
1407 }
1408
1409
1410 /*************************************************************************/
1411 /* */
1412 /* <Function> */
1413 /* tt_face_load_sbit_image */
1414 /* */
1415 /* <Description> */
1416 /* Loads a given glyph sbit image from the font resource. This also */
1417 /* returns its metrics. */
1418 /* */
1419 /* <Input> */
1420 /* face :: The target face object. */
1421 /* */
1422 /* strike_index :: The current strike index. */
1423 /* */
1424 /* glyph_index :: The current glyph index. */
1425 /* */
1426 /* load_flags :: The glyph load flags (the code checks for the flag */
1427 /* FT_LOAD_CROP_BITMAP). */
1428 /* */
1429 /* stream :: The input stream. */
1430 /* */
1431 /* <Output> */
1432 /* map :: The target pixmap. */
1433 /* */
1434 /* metrics :: A big sbit metrics structure for the glyph image. */
1435 /* */
1436 /* <Return> */
1437 /* FreeType error code. 0 means success. Returns an error if no */
1438 /* glyph sbit exists for the index. */
1439 /* */
1440 /* <Note> */
1441 /* The `map.buffer' field is always freed before the glyph is loaded. */
1442 /* */
1443 FT_LOCAL_DEF( FT_Error )
1444 tt_face_load_sbit_image( TT_Face face,
1445 FT_ULong strike_index,
1446 FT_UInt glyph_index,
1447 FT_UInt load_flags,
1448 FT_Stream stream,
1449 FT_Bitmap *map,
1450 TT_SBit_MetricsRec *metrics )
1451 {
1452 FT_Error error;
1453 FT_ULong ebdt_pos, glyph_offset;
1454
1455 TT_SBit_Strike strike;
1456 TT_SBit_Range range;
1457
1458
1459 /* Check whether there is a glyph sbit for the current index */
1460 error = tt_find_sbit_image( face, glyph_index, strike_index,
1461 &range, &strike, &glyph_offset );
1462 if ( error )
1463 goto Exit;
1464
1465 /* now, find the location of the `EBDT' table in */
1466 /* the font file */
1467 error = face->goto_table( face, TTAG_EBDT, stream, 0 );
1468 if ( error )
1469 error = face->goto_table( face, TTAG_bdat, stream, 0 );
1470 if ( error )
1471 goto Exit;
1472
1473 ebdt_pos = FT_STREAM_POS();
1474
1475 error = Load_SBit_Image( strike, range, ebdt_pos, glyph_offset,
1476 face->root.glyph, 0, 0, stream, metrics, 0 );
1477 if ( error )
1478 goto Exit;
1479
1480 /* setup vertical metrics if needed */
1481 if ( strike->flags & 1 )
1482 {
1483 /* in case of a horizontal strike only */
1484 FT_Int advance;
1485
1486
1487 advance = strike->hori.ascender - strike->hori.descender;
1488
1489 /* some heuristic values */
1490
1491 metrics->vertBearingX = (FT_Char)(-metrics->width / 2 );
1492 metrics->vertBearingY = (FT_Char)( ( advance - metrics->height ) / 2 );
1493 metrics->vertAdvance = (FT_Char)( advance * 12 / 10 );
1494 }
1495
1496 /* Crop the bitmap now, unless specified otherwise */
1497 if ( load_flags & FT_LOAD_CROP_BITMAP )
1498 crop_bitmap( map, metrics );
1499
1500 Exit:
1501 return error;
1502 }
1503
1504 #endif /* FT_CONFIG_OPTION_OLD_INTERNALS */
1505
1506
1507 /* END */
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