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[reactos.git] / reactos / 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, */
8 /* 2010 by */
9 /* David Turner, Robert Wilhelm, and Werner Lemberg. */
10 /* */
11 /* This file is part of the FreeType project, and may only be used, */
12 /* modified, and distributed under the terms of the FreeType project */
13 /* license, LICENSE.TXT. By continuing to use, modify, or distribute */
14 /* this file you indicate that you have read the license and */
15 /* understand and accept it fully. */
16 /* */
17 /***************************************************************************/
18
19 #include <ft2build.h>
20 #include FT_INTERNAL_DEBUG_H
21 #include FT_INTERNAL_STREAM_H
22 #include FT_TRUETYPE_TAGS_H
23
24 /*
25 * Alas, the memory-optimized sbit loader can't be used when implementing
26 * the `old internals' hack
27 */
28 #ifndef FT_CONFIG_OPTION_OLD_INTERNALS
29
30 #include "ttsbit0.c"
31
32 #else /* FT_CONFIG_OPTION_OLD_INTERNALS */
33
34 #include <ft2build.h>
35 #include FT_INTERNAL_DEBUG_H
36 #include FT_INTERNAL_STREAM_H
37 #include FT_TRUETYPE_TAGS_H
38 #include "ttsbit.h"
39
40 #include "sferrors.h"
41
42
43 /*************************************************************************/
44 /* */
45 /* The macro FT_COMPONENT is used in trace mode. It is an implicit */
46 /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */
47 /* messages during execution. */
48 /* */
49 #undef FT_COMPONENT
50 #define FT_COMPONENT trace_ttsbit
51
52
53 /*************************************************************************/
54 /* */
55 /* <Function> */
56 /* blit_sbit */
57 /* */
58 /* <Description> */
59 /* Blits a bitmap from an input stream into a given target. Supports */
60 /* x and y offsets as well as byte padded lines. */
61 /* */
62 /* <Input> */
63 /* target :: The target bitmap/pixmap. */
64 /* */
65 /* source :: The input packed bitmap data. */
66 /* */
67 /* line_bits :: The number of bits per line. */
68 /* */
69 /* byte_padded :: A flag which is true if lines are byte-padded. */
70 /* */
71 /* x_offset :: The horizontal offset. */
72 /* */
73 /* y_offset :: The vertical offset. */
74 /* */
75 /* <Note> */
76 /* IMPORTANT: The x and y offsets are relative to the top corner of */
77 /* the target bitmap (unlike the normal TrueType */
78 /* convention). A positive y offset indicates a downwards */
79 /* direction! */
80 /* */
81 static void
82 blit_sbit( FT_Bitmap* target,
83 FT_Byte* source,
84 FT_Int line_bits,
85 FT_Bool byte_padded,
86 FT_Int x_offset,
87 FT_Int y_offset,
88 FT_Int source_height )
89 {
90 FT_Byte* line_buff;
91 FT_Int line_incr;
92 FT_Int height;
93
94 FT_UShort acc;
95 FT_UInt loaded;
96
97
98 /* first of all, compute starting write position */
99 line_incr = target->pitch;
100 line_buff = target->buffer;
101
102 if ( line_incr < 0 )
103 line_buff -= line_incr * ( target->rows - 1 );
104
105 line_buff += ( x_offset >> 3 ) + y_offset * line_incr;
106
107 /***********************************************************************/
108 /* */
109 /* We use the extra-classic `accumulator' trick to extract the bits */
110 /* from the source byte stream. */
111 /* */
112 /* Namely, the variable `acc' is a 16-bit accumulator containing the */
113 /* last `loaded' bits from the input stream. The bits are shifted to */
114 /* the upmost position in `acc'. */
115 /* */
116 /***********************************************************************/
117
118 acc = 0; /* clear accumulator */
119 loaded = 0; /* no bits were loaded */
120
121 for ( height = source_height; height > 0; height-- )
122 {
123 FT_Byte* cur = line_buff; /* current write cursor */
124 FT_Int count = line_bits; /* # of bits to extract per line */
125 FT_Byte shift = (FT_Byte)( x_offset & 7 ); /* current write shift */
126 FT_Byte space = (FT_Byte)( 8 - shift );
127
128
129 /* first of all, read individual source bytes */
130 if ( count >= 8 )
131 {
132 count -= 8;
133 {
134 do
135 {
136 FT_Byte val;
137
138
139 /* ensure that there are at least 8 bits in the accumulator */
140 if ( loaded < 8 )
141 {
142 acc |= (FT_UShort)((FT_UShort)*source++ << ( 8 - loaded ));
143 loaded += 8;
144 }
145
146 /* now write one byte */
147 val = (FT_Byte)( acc >> 8 );
148 if ( shift )
149 {
150 cur[0] |= (FT_Byte)( val >> shift );
151 cur[1] |= (FT_Byte)( val << space );
152 }
153 else
154 cur[0] |= val;
155
156 cur++;
157 acc <<= 8; /* remove bits from accumulator */
158 loaded -= 8;
159 count -= 8;
160
161 } while ( count >= 0 );
162 }
163
164 /* restore `count' to correct value */
165 count += 8;
166 }
167
168 /* now write remaining bits (count < 8) */
169 if ( count > 0 )
170 {
171 FT_Byte val;
172
173
174 /* ensure that there are at least `count' bits in the accumulator */
175 if ( (FT_Int)loaded < count )
176 {
177 acc |= (FT_UShort)((FT_UShort)*source++ << ( 8 - loaded ));
178 loaded += 8;
179 }
180
181 /* now write remaining bits */
182 val = (FT_Byte)( ( (FT_Byte)( acc >> 8 ) ) & ~( 0xFF >> count ) );
183 cur[0] |= (FT_Byte)( val >> shift );
184
185 if ( count > space )
186 cur[1] |= (FT_Byte)( val << space );
187
188 acc <<= count;
189 loaded -= count;
190 }
191
192 /* now, skip to next line */
193 if ( byte_padded )
194 {
195 acc = 0;
196 loaded = 0; /* clear accumulator on byte-padded lines */
197 }
198
199 line_buff += line_incr;
200 }
201 }
202
203
204 static const FT_Frame_Field sbit_metrics_fields[] =
205 {
206 #undef FT_STRUCTURE
207 #define FT_STRUCTURE TT_SBit_MetricsRec
208
209 FT_FRAME_START( 8 ),
210 FT_FRAME_BYTE( height ),
211 FT_FRAME_BYTE( width ),
212
213 FT_FRAME_CHAR( horiBearingX ),
214 FT_FRAME_CHAR( horiBearingY ),
215 FT_FRAME_BYTE( horiAdvance ),
216
217 FT_FRAME_CHAR( vertBearingX ),
218 FT_FRAME_CHAR( vertBearingY ),
219 FT_FRAME_BYTE( vertAdvance ),
220 FT_FRAME_END
221 };
222
223
224 /*************************************************************************/
225 /* */
226 /* <Function> */
227 /* Load_SBit_Const_Metrics */
228 /* */
229 /* <Description> */
230 /* Loads the metrics for `EBLC' index tables format 2 and 5. */
231 /* */
232 /* <Input> */
233 /* range :: The target range. */
234 /* */
235 /* stream :: The input stream. */
236 /* */
237 /* <Return> */
238 /* FreeType error code. 0 means success. */
239 /* */
240 static FT_Error
241 Load_SBit_Const_Metrics( TT_SBit_Range range,
242 FT_Stream stream )
243 {
244 FT_Error error;
245
246
247 if ( FT_READ_ULONG( range->image_size ) )
248 return error;
249
250 return FT_STREAM_READ_FIELDS( sbit_metrics_fields, &range->metrics );
251 }
252
253
254 /*************************************************************************/
255 /* */
256 /* <Function> */
257 /* Load_SBit_Range_Codes */
258 /* */
259 /* <Description> */
260 /* Loads the range codes for `EBLC' index tables format 4 and 5. */
261 /* */
262 /* <Input> */
263 /* range :: The target range. */
264 /* */
265 /* stream :: The input stream. */
266 /* */
267 /* load_offsets :: A flag whether to load the glyph offset table. */
268 /* */
269 /* <Return> */
270 /* FreeType error code. 0 means success. */
271 /* */
272 static FT_Error
273 Load_SBit_Range_Codes( TT_SBit_Range range,
274 FT_Stream stream,
275 FT_Bool load_offsets )
276 {
277 FT_Error error;
278 FT_ULong count, n, size;
279 FT_Memory memory = stream->memory;
280
281
282 if ( FT_READ_ULONG( count ) )
283 goto Exit;
284
285 range->num_glyphs = count;
286
287 /* Allocate glyph offsets table if needed */
288 if ( load_offsets )
289 {
290 if ( FT_NEW_ARRAY( range->glyph_offsets, count ) )
291 goto Exit;
292
293 size = count * 4L;
294 }
295 else
296 size = count * 2L;
297
298 /* Allocate glyph codes table and access frame */
299 if ( FT_NEW_ARRAY ( range->glyph_codes, count ) ||
300 FT_FRAME_ENTER( size ) )
301 goto Exit;
302
303 for ( n = 0; n < count; n++ )
304 {
305 range->glyph_codes[n] = FT_GET_USHORT();
306
307 if ( load_offsets )
308 range->glyph_offsets[n] = (FT_ULong)range->image_offset +
309 FT_GET_USHORT();
310 }
311
312 FT_FRAME_EXIT();
313
314 Exit:
315 return error;
316 }
317
318
319 /*************************************************************************/
320 /* */
321 /* <Function> */
322 /* Load_SBit_Range */
323 /* */
324 /* <Description> */
325 /* Loads a given `EBLC' index/range table. */
326 /* */
327 /* <Input> */
328 /* range :: The target range. */
329 /* */
330 /* stream :: The input stream. */
331 /* */
332 /* <Return> */
333 /* FreeType error code. 0 means success. */
334 /* */
335 static FT_Error
336 Load_SBit_Range( TT_SBit_Range range,
337 FT_Stream stream )
338 {
339 FT_Error error;
340 FT_Memory memory = stream->memory;
341
342
343 switch( range->index_format )
344 {
345 case 1: /* variable metrics with 4-byte offsets */
346 case 3: /* variable metrics with 2-byte offsets */
347 {
348 FT_ULong num_glyphs, n;
349 FT_Int size_elem;
350 FT_Bool large = FT_BOOL( range->index_format == 1 );
351
352
353
354 if ( range->last_glyph < range->first_glyph )
355 {
356 error = SFNT_Err_Invalid_File_Format;
357 goto Exit;
358 }
359
360 num_glyphs = range->last_glyph - range->first_glyph + 1L;
361 range->num_glyphs = num_glyphs;
362 num_glyphs++; /* XXX: BEWARE - see spec */
363
364 size_elem = large ? 4 : 2;
365
366 if ( FT_NEW_ARRAY( range->glyph_offsets, num_glyphs ) ||
367 FT_FRAME_ENTER( num_glyphs * size_elem ) )
368 goto Exit;
369
370 for ( n = 0; n < num_glyphs; n++ )
371 range->glyph_offsets[n] = (FT_ULong)( range->image_offset +
372 ( large ? FT_GET_ULONG()
373 : FT_GET_USHORT() ) );
374 FT_FRAME_EXIT();
375 }
376 break;
377
378 case 2: /* all glyphs have identical metrics */
379 error = Load_SBit_Const_Metrics( range, stream );
380 break;
381
382 case 4:
383 error = Load_SBit_Range_Codes( range, stream, 1 );
384 break;
385
386 case 5:
387 error = Load_SBit_Const_Metrics( range, stream );
388 if ( !error )
389 error = Load_SBit_Range_Codes( range, stream, 0 );
390 break;
391
392 default:
393 error = SFNT_Err_Invalid_File_Format;
394 }
395
396 Exit:
397 return error;
398 }
399
400
401 /*************************************************************************/
402 /* */
403 /* <Function> */
404 /* tt_face_load_eblc */
405 /* */
406 /* <Description> */
407 /* Loads the table of embedded bitmap sizes for this face. */
408 /* */
409 /* <Input> */
410 /* face :: The target face object. */
411 /* */
412 /* stream :: The input stream. */
413 /* */
414 /* <Return> */
415 /* FreeType error code. 0 means success. */
416 /* */
417 FT_LOCAL_DEF( FT_Error )
418 tt_face_load_eblc( TT_Face face,
419 FT_Stream stream )
420 {
421 FT_Error error = SFNT_Err_Ok;
422 FT_Memory memory = stream->memory;
423 FT_Fixed version;
424 FT_ULong num_strikes;
425 FT_ULong table_base;
426
427 static const FT_Frame_Field sbit_line_metrics_fields[] =
428 {
429 #undef FT_STRUCTURE
430 #define FT_STRUCTURE TT_SBit_LineMetricsRec
431
432 /* no FT_FRAME_START */
433 FT_FRAME_CHAR( ascender ),
434 FT_FRAME_CHAR( descender ),
435 FT_FRAME_BYTE( max_width ),
436
437 FT_FRAME_CHAR( caret_slope_numerator ),
438 FT_FRAME_CHAR( caret_slope_denominator ),
439 FT_FRAME_CHAR( caret_offset ),
440
441 FT_FRAME_CHAR( min_origin_SB ),
442 FT_FRAME_CHAR( min_advance_SB ),
443 FT_FRAME_CHAR( max_before_BL ),
444 FT_FRAME_CHAR( min_after_BL ),
445 FT_FRAME_CHAR( pads[0] ),
446 FT_FRAME_CHAR( pads[1] ),
447 FT_FRAME_END
448 };
449
450 static const FT_Frame_Field strike_start_fields[] =
451 {
452 #undef FT_STRUCTURE
453 #define FT_STRUCTURE TT_SBit_StrikeRec
454
455 /* no FT_FRAME_START */
456 FT_FRAME_ULONG( ranges_offset ),
457 FT_FRAME_SKIP_LONG,
458 FT_FRAME_ULONG( num_ranges ),
459 FT_FRAME_ULONG( color_ref ),
460 FT_FRAME_END
461 };
462
463 static const FT_Frame_Field strike_end_fields[] =
464 {
465 /* no FT_FRAME_START */
466 FT_FRAME_USHORT( start_glyph ),
467 FT_FRAME_USHORT( end_glyph ),
468 FT_FRAME_BYTE ( x_ppem ),
469 FT_FRAME_BYTE ( y_ppem ),
470 FT_FRAME_BYTE ( bit_depth ),
471 FT_FRAME_CHAR ( flags ),
472 FT_FRAME_END
473 };
474
475
476 face->num_sbit_strikes = 0;
477
478 /* this table is optional */
479 error = face->goto_table( face, TTAG_EBLC, stream, 0 );
480 if ( error )
481 error = face->goto_table( face, TTAG_bloc, stream, 0 );
482 if ( error )
483 goto Exit;
484
485 table_base = FT_STREAM_POS();
486 if ( FT_FRAME_ENTER( 8L ) )
487 goto Exit;
488
489 version = FT_GET_LONG();
490 num_strikes = FT_GET_ULONG();
491
492 FT_FRAME_EXIT();
493
494 /* check version number and strike count */
495 if ( version != 0x00020000L ||
496 num_strikes >= 0x10000L )
497 {
498 FT_ERROR(( "tt_face_load_sbit_strikes: invalid table version\n" ));
499 error = SFNT_Err_Invalid_File_Format;
500
501 goto Exit;
502 }
503
504 /* allocate the strikes table */
505 if ( FT_NEW_ARRAY( face->sbit_strikes, num_strikes ) )
506 goto Exit;
507
508 face->num_sbit_strikes = num_strikes;
509
510 /* now read each strike table separately */
511 {
512 TT_SBit_Strike strike = face->sbit_strikes;
513 FT_ULong count = num_strikes;
514
515
516 if ( FT_FRAME_ENTER( 48L * num_strikes ) )
517 goto Exit;
518
519 while ( count > 0 )
520 {
521 if ( FT_STREAM_READ_FIELDS( strike_start_fields, strike ) ||
522 FT_STREAM_READ_FIELDS( sbit_line_metrics_fields, &strike->hori ) ||
523 FT_STREAM_READ_FIELDS( sbit_line_metrics_fields, &strike->vert ) ||
524 FT_STREAM_READ_FIELDS( strike_end_fields, strike ) )
525 break;
526
527 count--;
528 strike++;
529 }
530
531 FT_FRAME_EXIT();
532 }
533
534 /* allocate the index ranges for each strike table */
535 {
536 TT_SBit_Strike strike = face->sbit_strikes;
537 FT_ULong count = num_strikes;
538
539
540 while ( count > 0 )
541 {
542 TT_SBit_Range range;
543 FT_ULong count2 = strike->num_ranges;
544
545
546 /* read each range */
547 if ( FT_STREAM_SEEK( table_base + strike->ranges_offset ) ||
548 FT_FRAME_ENTER( strike->num_ranges * 8L ) )
549 goto Exit;
550
551 if ( FT_NEW_ARRAY( strike->sbit_ranges, strike->num_ranges ) )
552 goto Exit;
553
554 range = strike->sbit_ranges;
555 while ( count2 > 0 )
556 {
557 range->first_glyph = FT_GET_USHORT();
558 range->last_glyph = FT_GET_USHORT();
559 range->table_offset = table_base + strike->ranges_offset +
560 FT_GET_ULONG();
561 count2--;
562 range++;
563 }
564
565 FT_FRAME_EXIT();
566
567 /* Now, read each index table */
568 count2 = strike->num_ranges;
569 range = strike->sbit_ranges;
570 while ( count2 > 0 )
571 {
572 /* Read the header */
573 if ( FT_STREAM_SEEK( range->table_offset ) ||
574 FT_FRAME_ENTER( 8L ) )
575 goto Exit;
576
577 range->index_format = FT_GET_USHORT();
578 range->image_format = FT_GET_USHORT();
579 range->image_offset = FT_GET_ULONG();
580
581 FT_FRAME_EXIT();
582
583 error = Load_SBit_Range( range, stream );
584 if ( error )
585 goto Exit;
586
587 count2--;
588 range++;
589 }
590
591 count--;
592 strike++;
593 }
594 }
595
596 Exit:
597 return error;
598 }
599
600
601 /*************************************************************************/
602 /* */
603 /* <Function> */
604 /* tt_face_free_eblc */
605 /* */
606 /* <Description> */
607 /* Releases the embedded bitmap tables. */
608 /* */
609 /* <Input> */
610 /* face :: The target face object. */
611 /* */
612 FT_LOCAL_DEF( void )
613 tt_face_free_eblc( TT_Face face )
614 {
615 FT_Memory memory = face->root.memory;
616 TT_SBit_Strike strike = face->sbit_strikes;
617 TT_SBit_Strike strike_limit = strike + face->num_sbit_strikes;
618
619
620 if ( strike )
621 {
622 for ( ; strike < strike_limit; strike++ )
623 {
624 TT_SBit_Range range = strike->sbit_ranges;
625 TT_SBit_Range range_limit = range + strike->num_ranges;
626
627
628 if ( range )
629 {
630 for ( ; range < range_limit; range++ )
631 {
632 /* release the glyph offsets and codes tables */
633 /* where appropriate */
634 FT_FREE( range->glyph_offsets );
635 FT_FREE( range->glyph_codes );
636 }
637 }
638 FT_FREE( strike->sbit_ranges );
639 strike->num_ranges = 0;
640 }
641 FT_FREE( face->sbit_strikes );
642 }
643 face->num_sbit_strikes = 0;
644 }
645
646
647 FT_LOCAL_DEF( FT_Error )
648 tt_face_set_sbit_strike( TT_Face face,
649 FT_Size_Request req,
650 FT_ULong* astrike_index )
651 {
652 return FT_Match_Size( (FT_Face)face, req, 0, astrike_index );
653 }
654
655
656 FT_LOCAL_DEF( FT_Error )
657 tt_face_load_strike_metrics( TT_Face face,
658 FT_ULong strike_index,
659 FT_Size_Metrics* metrics )
660 {
661 TT_SBit_Strike strike;
662
663
664 if ( strike_index >= face->num_sbit_strikes )
665 return SFNT_Err_Invalid_Argument;
666
667 strike = face->sbit_strikes + strike_index;
668
669 metrics->x_ppem = strike->x_ppem;
670 metrics->y_ppem = strike->y_ppem;
671
672 metrics->ascender = strike->hori.ascender << 6;
673 metrics->descender = strike->hori.descender << 6;
674
675 /* XXX: Is this correct? */
676 metrics->max_advance = ( strike->hori.min_origin_SB +
677 strike->hori.max_width +
678 strike->hori.min_advance_SB ) << 6;
679
680 metrics->height = metrics->ascender - metrics->descender;
681
682 return SFNT_Err_Ok;
683 }
684
685
686 /*************************************************************************/
687 /* */
688 /* <Function> */
689 /* find_sbit_range */
690 /* */
691 /* <Description> */
692 /* Scans a given strike's ranges and return, for a given glyph */
693 /* index, the corresponding sbit range, and `EBDT' offset. */
694 /* */
695 /* <Input> */
696 /* glyph_index :: The glyph index. */
697 /* */
698 /* strike :: The source/current sbit strike. */
699 /* */
700 /* <Output> */
701 /* arange :: The sbit range containing the glyph index. */
702 /* */
703 /* aglyph_offset :: The offset of the glyph data in `EBDT' table. */
704 /* */
705 /* <Return> */
706 /* FreeType error code. 0 means the glyph index was found. */
707 /* */
708 static FT_Error
709 find_sbit_range( FT_UInt glyph_index,
710 TT_SBit_Strike strike,
711 TT_SBit_Range *arange,
712 FT_ULong *aglyph_offset )
713 {
714 TT_SBit_RangeRec *range, *range_limit;
715
716
717 /* check whether the glyph index is within this strike's */
718 /* glyph range */
719 if ( glyph_index < (FT_UInt)strike->start_glyph ||
720 glyph_index > (FT_UInt)strike->end_glyph )
721 goto Fail;
722
723 /* scan all ranges in strike */
724 range = strike->sbit_ranges;
725 range_limit = range + strike->num_ranges;
726 if ( !range )
727 goto Fail;
728
729 for ( ; range < range_limit; range++ )
730 {
731 if ( glyph_index >= (FT_UInt)range->first_glyph &&
732 glyph_index <= (FT_UInt)range->last_glyph )
733 {
734 FT_UShort delta = (FT_UShort)( glyph_index - range->first_glyph );
735
736
737 switch ( range->index_format )
738 {
739 case 1:
740 case 3:
741 *aglyph_offset = range->glyph_offsets[delta];
742 break;
743
744 case 2:
745 *aglyph_offset = range->image_offset +
746 range->image_size * delta;
747 break;
748
749 case 4:
750 case 5:
751 {
752 FT_ULong n;
753
754
755 for ( n = 0; n < range->num_glyphs; n++ )
756 {
757 if ( (FT_UInt)range->glyph_codes[n] == glyph_index )
758 {
759 if ( range->index_format == 4 )
760 *aglyph_offset = range->glyph_offsets[n];
761 else
762 *aglyph_offset = range->image_offset +
763 n * range->image_size;
764 goto Found;
765 }
766 }
767 }
768
769 /* fall-through */
770 default:
771 goto Fail;
772 }
773
774 Found:
775 /* return successfully! */
776 *arange = range;
777 return SFNT_Err_Ok;
778 }
779 }
780
781 Fail:
782 *arange = 0;
783 *aglyph_offset = 0;
784
785 return SFNT_Err_Invalid_Argument;
786 }
787
788
789 /*************************************************************************/
790 /* */
791 /* <Function> */
792 /* tt_find_sbit_image */
793 /* */
794 /* <Description> */
795 /* Checks whether an embedded bitmap (an `sbit') exists for a given */
796 /* glyph, at a given strike. */
797 /* */
798 /* <Input> */
799 /* face :: The target face object. */
800 /* */
801 /* glyph_index :: The glyph index. */
802 /* */
803 /* strike_index :: The current strike index. */
804 /* */
805 /* <Output> */
806 /* arange :: The SBit range containing the glyph index. */
807 /* */
808 /* astrike :: The SBit strike containing the glyph index. */
809 /* */
810 /* aglyph_offset :: The offset of the glyph data in `EBDT' table. */
811 /* */
812 /* <Return> */
813 /* FreeType error code. 0 means success. Returns */
814 /* SFNT_Err_Invalid_Argument if no sbit exists for the requested */
815 /* glyph. */
816 /* */
817 FT_LOCAL( FT_Error )
818 tt_find_sbit_image( TT_Face face,
819 FT_UInt glyph_index,
820 FT_ULong strike_index,
821 TT_SBit_Range *arange,
822 TT_SBit_Strike *astrike,
823 FT_ULong *aglyph_offset )
824 {
825 FT_Error error;
826 TT_SBit_Strike strike;
827
828
829 if ( !face->sbit_strikes ||
830 ( face->num_sbit_strikes <= strike_index ) )
831 goto Fail;
832
833 strike = &face->sbit_strikes[strike_index];
834
835 error = find_sbit_range( glyph_index, strike,
836 arange, aglyph_offset );
837 if ( error )
838 goto Fail;
839
840 *astrike = strike;
841
842 return SFNT_Err_Ok;
843
844 Fail:
845 /* no embedded bitmap for this glyph in face */
846 *arange = 0;
847 *astrike = 0;
848 *aglyph_offset = 0;
849
850 return SFNT_Err_Invalid_Argument;
851 }
852
853
854 /*************************************************************************/
855 /* */
856 /* <Function> */
857 /* tt_load_sbit_metrics */
858 /* */
859 /* <Description> */
860 /* Gets the big metrics for a given SBit. */
861 /* */
862 /* <Input> */
863 /* stream :: The input stream. */
864 /* */
865 /* range :: The SBit range containing the glyph. */
866 /* */
867 /* <Output> */
868 /* big_metrics :: A big SBit metrics structure for the glyph. */
869 /* */
870 /* <Return> */
871 /* FreeType error code. 0 means success. */
872 /* */
873 /* <Note> */
874 /* The stream cursor must be positioned at the glyph's offset within */
875 /* the `EBDT' table before the call. */
876 /* */
877 /* If the image format uses variable metrics, the stream cursor is */
878 /* positioned just after the metrics header in the `EBDT' table on */
879 /* function exit. */
880 /* */
881 FT_LOCAL( FT_Error )
882 tt_load_sbit_metrics( FT_Stream stream,
883 TT_SBit_Range range,
884 TT_SBit_Metrics metrics )
885 {
886 FT_Error error = SFNT_Err_Ok;
887
888
889 switch ( range->image_format )
890 {
891 case 1:
892 case 2:
893 case 8:
894 /* variable small metrics */
895 {
896 TT_SBit_SmallMetricsRec smetrics;
897
898 static const FT_Frame_Field sbit_small_metrics_fields[] =
899 {
900 #undef FT_STRUCTURE
901 #define FT_STRUCTURE TT_SBit_SmallMetricsRec
902
903 FT_FRAME_START( 5 ),
904 FT_FRAME_BYTE( height ),
905 FT_FRAME_BYTE( width ),
906 FT_FRAME_CHAR( bearingX ),
907 FT_FRAME_CHAR( bearingY ),
908 FT_FRAME_BYTE( advance ),
909 FT_FRAME_END
910 };
911
912
913 /* read small metrics */
914 if ( FT_STREAM_READ_FIELDS( sbit_small_metrics_fields, &smetrics ) )
915 goto Exit;
916
917 /* convert it to a big metrics */
918 metrics->height = smetrics.height;
919 metrics->width = smetrics.width;
920 metrics->horiBearingX = smetrics.bearingX;
921 metrics->horiBearingY = smetrics.bearingY;
922 metrics->horiAdvance = smetrics.advance;
923
924 /* these metrics are made up at a higher level when */
925 /* needed. */
926 metrics->vertBearingX = 0;
927 metrics->vertBearingY = 0;
928 metrics->vertAdvance = 0;
929 }
930 break;
931
932 case 6:
933 case 7:
934 case 9:
935 /* variable big metrics */
936 if ( FT_STREAM_READ_FIELDS( sbit_metrics_fields, metrics ) )
937 goto Exit;
938 break;
939
940 case 5:
941 default: /* constant metrics */
942 if ( range->index_format == 2 || range->index_format == 5 )
943 *metrics = range->metrics;
944 else
945 return SFNT_Err_Invalid_File_Format;
946 }
947
948 Exit:
949 return error;
950 }
951
952
953 /*************************************************************************/
954 /* */
955 /* <Function> */
956 /* crop_bitmap */
957 /* */
958 /* <Description> */
959 /* Crops a bitmap to its tightest bounding box, and adjusts its */
960 /* metrics. */
961 /* */
962 /* <InOut> */
963 /* map :: The bitmap. */
964 /* */
965 /* metrics :: The corresponding metrics structure. */
966 /* */
967 static void
968 crop_bitmap( FT_Bitmap* map,
969 TT_SBit_Metrics metrics )
970 {
971 /***********************************************************************/
972 /* */
973 /* In this situation, some bounding boxes of embedded bitmaps are too */
974 /* large. We need to crop it to a reasonable size. */
975 /* */
976 /* --------- */
977 /* | | ----- */
978 /* | *** | |***| */
979 /* | * | | * | */
980 /* | * | ------> | * | */
981 /* | * | | * | */
982 /* | * | | * | */
983 /* | *** | |***| */
984 /* --------- ----- */
985 /* */
986 /***********************************************************************/
987
988 FT_Int rows, count;
989 FT_Long line_len;
990 FT_Byte* line;
991
992
993 /***********************************************************************/
994 /* */
995 /* first of all, check the top-most lines of the bitmap, and remove */
996 /* them if they're empty. */
997 /* */
998 {
999 line = (FT_Byte*)map->buffer;
1000 rows = map->rows;
1001 line_len = map->pitch;
1002
1003
1004 for ( count = 0; count < rows; count++ )
1005 {
1006 FT_Byte* cur = line;
1007 FT_Byte* limit = line + line_len;
1008
1009
1010 for ( ; cur < limit; cur++ )
1011 if ( cur[0] )
1012 goto Found_Top;
1013
1014 /* the current line was empty - skip to next one */
1015 line = limit;
1016 }
1017
1018 Found_Top:
1019 /* check that we have at least one filled line */
1020 if ( count >= rows )
1021 goto Empty_Bitmap;
1022
1023 /* now, crop the empty upper lines */
1024 if ( count > 0 )
1025 {
1026 line = (FT_Byte*)map->buffer;
1027
1028 FT_MEM_MOVE( line, line + count * line_len,
1029 ( rows - count ) * line_len );
1030
1031 metrics->height = (FT_Byte)( metrics->height - count );
1032 metrics->horiBearingY = (FT_Char)( metrics->horiBearingY - count );
1033 metrics->vertBearingY = (FT_Char)( metrics->vertBearingY - count );
1034
1035 map->rows -= count;
1036 rows -= count;
1037 }
1038 }
1039
1040 /***********************************************************************/
1041 /* */
1042 /* second, crop the lower lines */
1043 /* */
1044 {
1045 line = (FT_Byte*)map->buffer + ( rows - 1 ) * line_len;
1046
1047 for ( count = 0; count < rows; count++ )
1048 {
1049 FT_Byte* cur = line;
1050 FT_Byte* limit = line + line_len;
1051
1052
1053 for ( ; cur < limit; cur++ )
1054 if ( cur[0] )
1055 goto Found_Bottom;
1056
1057 /* the current line was empty - skip to previous one */
1058 line -= line_len;
1059 }
1060
1061 Found_Bottom:
1062 if ( count > 0 )
1063 {
1064 metrics->height = (FT_Byte)( metrics->height - count );
1065 rows -= count;
1066 map->rows -= count;
1067 }
1068 }
1069
1070 /***********************************************************************/
1071 /* */
1072 /* third, get rid of the space on the left side of the glyph */
1073 /* */
1074 do
1075 {
1076 FT_Byte* limit;
1077
1078
1079 line = (FT_Byte*)map->buffer;
1080 limit = line + rows * line_len;
1081
1082 for ( ; line < limit; line += line_len )
1083 if ( line[0] & 0x80 )
1084 goto Found_Left;
1085
1086 /* shift the whole glyph one pixel to the left */
1087 line = (FT_Byte*)map->buffer;
1088 limit = line + rows * line_len;
1089
1090 for ( ; line < limit; line += line_len )
1091 {
1092 FT_Int n, width = map->width;
1093 FT_Byte old;
1094 FT_Byte* cur = line;
1095
1096
1097 old = (FT_Byte)(cur[0] << 1);
1098 for ( n = 8; n < width; n += 8 )
1099 {
1100 FT_Byte val;
1101
1102
1103 val = cur[1];
1104 cur[0] = (FT_Byte)( old | ( val >> 7 ) );
1105 old = (FT_Byte)( val << 1 );
1106 cur++;
1107 }
1108 cur[0] = old;
1109 }
1110
1111 map->width--;
1112 metrics->horiBearingX++;
1113 metrics->vertBearingX++;
1114 metrics->width--;
1115
1116 } while ( map->width > 0 );
1117
1118 Found_Left:
1119
1120 /***********************************************************************/
1121 /* */
1122 /* finally, crop the bitmap width to get rid of the space on the right */
1123 /* side of the glyph. */
1124 /* */
1125 do
1126 {
1127 FT_Int right = map->width - 1;
1128 FT_Byte* limit;
1129 FT_Byte mask;
1130
1131
1132 line = (FT_Byte*)map->buffer + ( right >> 3 );
1133 limit = line + rows * line_len;
1134 mask = (FT_Byte)( 0x80 >> ( right & 7 ) );
1135
1136 for ( ; line < limit; line += line_len )
1137 if ( line[0] & mask )
1138 goto Found_Right;
1139
1140 /* crop the whole glyph to the right */
1141 map->width--;
1142 metrics->width--;
1143
1144 } while ( map->width > 0 );
1145
1146 Found_Right:
1147 /* all right, the bitmap was cropped */
1148 return;
1149
1150 Empty_Bitmap:
1151 map->width = 0;
1152 map->rows = 0;
1153 map->pitch = 0;
1154 map->pixel_mode = FT_PIXEL_MODE_MONO;
1155 }
1156
1157
1158 static FT_Error
1159 Load_SBit_Single( FT_Bitmap* map,
1160 FT_Int x_offset,
1161 FT_Int y_offset,
1162 FT_Int pix_bits,
1163 FT_UShort image_format,
1164 TT_SBit_Metrics metrics,
1165 FT_Stream stream )
1166 {
1167 FT_Error error;
1168
1169
1170 /* check that the source bitmap fits into the target pixmap */
1171 if ( x_offset < 0 || x_offset + metrics->width > map->width ||
1172 y_offset < 0 || y_offset + metrics->height > map->rows )
1173 {
1174 error = SFNT_Err_Invalid_Argument;
1175
1176 goto Exit;
1177 }
1178
1179 {
1180 FT_Int glyph_width = metrics->width;
1181 FT_Int glyph_height = metrics->height;
1182 FT_Int glyph_size;
1183 FT_Int line_bits = pix_bits * glyph_width;
1184 FT_Bool pad_bytes = 0;
1185
1186
1187 /* compute size of glyph image */
1188 switch ( image_format )
1189 {
1190 case 1: /* byte-padded formats */
1191 case 6:
1192 {
1193 FT_Int line_length;
1194
1195
1196 switch ( pix_bits )
1197 {
1198 case 1:
1199 line_length = ( glyph_width + 7 ) >> 3;
1200 break;
1201 case 2:
1202 line_length = ( glyph_width + 3 ) >> 2;
1203 break;
1204 case 4:
1205 line_length = ( glyph_width + 1 ) >> 1;
1206 break;
1207 default:
1208 line_length = glyph_width;
1209 }
1210
1211 glyph_size = glyph_height * line_length;
1212 pad_bytes = 1;
1213 }
1214 break;
1215
1216 case 2:
1217 case 5:
1218 case 7:
1219 line_bits = glyph_width * pix_bits;
1220 glyph_size = ( glyph_height * line_bits + 7 ) >> 3;
1221 break;
1222
1223 default: /* invalid format */
1224 return SFNT_Err_Invalid_File_Format;
1225 }
1226
1227 /* Now read data and draw glyph into target pixmap */
1228 if ( FT_FRAME_ENTER( glyph_size ) )
1229 goto Exit;
1230
1231 /* don't forget to multiply `x_offset' by `map->pix_bits' as */
1232 /* the sbit blitter doesn't make a difference between pixmap */
1233 /* depths. */
1234 blit_sbit( map, (FT_Byte*)stream->cursor, line_bits, pad_bytes,
1235 x_offset * pix_bits, y_offset, metrics->height );
1236
1237 FT_FRAME_EXIT();
1238 }
1239
1240 Exit:
1241 return error;
1242 }
1243
1244
1245 static FT_Error
1246 Load_SBit_Image( TT_SBit_Strike strike,
1247 TT_SBit_Range range,
1248 FT_ULong ebdt_pos,
1249 FT_ULong glyph_offset,
1250 FT_GlyphSlot slot,
1251 FT_Int x_offset,
1252 FT_Int y_offset,
1253 FT_Stream stream,
1254 TT_SBit_Metrics metrics,
1255 FT_Int depth )
1256 {
1257 FT_Memory memory = stream->memory;
1258 FT_Bitmap* map = &slot->bitmap;
1259 FT_Error error;
1260
1261
1262 /* place stream at beginning of glyph data and read metrics */
1263 if ( FT_STREAM_SEEK( ebdt_pos + glyph_offset ) )
1264 goto Exit;
1265
1266 error = tt_load_sbit_metrics( stream, range, metrics );
1267 if ( error )
1268 goto Exit;
1269
1270 /* This function is recursive. At the top-level call, we */
1271 /* compute the dimensions of the higher-level glyph to */
1272 /* allocate the final pixmap buffer. */
1273 if ( depth == 0 )
1274 {
1275 FT_Long size;
1276
1277
1278 map->width = metrics->width;
1279 map->rows = metrics->height;
1280
1281 switch ( strike->bit_depth )
1282 {
1283 case 1:
1284 map->pixel_mode = FT_PIXEL_MODE_MONO;
1285 map->pitch = ( map->width + 7 ) >> 3;
1286 break;
1287
1288 case 2:
1289 map->pixel_mode = FT_PIXEL_MODE_GRAY2;
1290 map->pitch = ( map->width + 3 ) >> 2;
1291 break;
1292
1293 case 4:
1294 map->pixel_mode = FT_PIXEL_MODE_GRAY4;
1295 map->pitch = ( map->width + 1 ) >> 1;
1296 break;
1297
1298 case 8:
1299 map->pixel_mode = FT_PIXEL_MODE_GRAY;
1300 map->pitch = map->width;
1301 break;
1302
1303 default:
1304 return SFNT_Err_Invalid_File_Format;
1305 }
1306
1307 size = map->rows * map->pitch;
1308
1309 /* check that there is no empty image */
1310 if ( size == 0 )
1311 goto Exit; /* exit successfully! */
1312
1313 error = ft_glyphslot_alloc_bitmap( slot, size );
1314 if (error)
1315 goto Exit;
1316 }
1317
1318 switch ( range->image_format )
1319 {
1320 case 1: /* single sbit image - load it */
1321 case 2:
1322 case 5:
1323 case 6:
1324 case 7:
1325 return Load_SBit_Single( map, x_offset, y_offset, strike->bit_depth,
1326 range->image_format, metrics, stream );
1327
1328 case 8: /* compound format */
1329 if ( FT_STREAM_SKIP( 1L ) )
1330 {
1331 error = SFNT_Err_Invalid_Stream_Skip;
1332 goto Exit;
1333 }
1334 /* fallthrough */
1335
1336 case 9:
1337 break;
1338
1339 default: /* invalid image format */
1340 return SFNT_Err_Invalid_File_Format;
1341 }
1342
1343 /* All right, we have a compound format. First of all, read */
1344 /* the array of elements. */
1345 {
1346 TT_SBit_Component components;
1347 TT_SBit_Component comp;
1348 FT_UShort num_components, count;
1349
1350
1351 if ( FT_READ_USHORT( num_components ) ||
1352 FT_NEW_ARRAY( components, num_components ) )
1353 goto Exit;
1354
1355 count = num_components;
1356
1357 if ( FT_FRAME_ENTER( 4L * num_components ) )
1358 goto Fail_Memory;
1359
1360 for ( comp = components; count > 0; count--, comp++ )
1361 {
1362 comp->glyph_code = FT_GET_USHORT();
1363 comp->x_offset = FT_GET_CHAR();
1364 comp->y_offset = FT_GET_CHAR();
1365 }
1366
1367 FT_FRAME_EXIT();
1368
1369 /* Now recursively load each element glyph */
1370 count = num_components;
1371 comp = components;
1372 for ( ; count > 0; count--, comp++ )
1373 {
1374 TT_SBit_Range elem_range;
1375 TT_SBit_MetricsRec elem_metrics;
1376 FT_ULong elem_offset;
1377
1378
1379 /* find the range for this element */
1380 error = find_sbit_range( comp->glyph_code,
1381 strike,
1382 &elem_range,
1383 &elem_offset );
1384 if ( error )
1385 goto Fail_Memory;
1386
1387 /* now load the element, recursively */
1388 error = Load_SBit_Image( strike,
1389 elem_range,
1390 ebdt_pos,
1391 elem_offset,
1392 slot,
1393 x_offset + comp->x_offset,
1394 y_offset + comp->y_offset,
1395 stream,
1396 &elem_metrics,
1397 depth + 1 );
1398 if ( error )
1399 goto Fail_Memory;
1400 }
1401
1402 Fail_Memory:
1403 FT_FREE( components );
1404 }
1405
1406 Exit:
1407 return error;
1408 }
1409
1410
1411 /*************************************************************************/
1412 /* */
1413 /* <Function> */
1414 /* tt_face_load_sbit_image */
1415 /* */
1416 /* <Description> */
1417 /* Loads a given glyph sbit image from the font resource. This also */
1418 /* returns its metrics. */
1419 /* */
1420 /* <Input> */
1421 /* face :: The target face object. */
1422 /* */
1423 /* strike_index :: The current strike index. */
1424 /* */
1425 /* glyph_index :: The current glyph index. */
1426 /* */
1427 /* load_flags :: The glyph load flags (the code checks for the flag */
1428 /* FT_LOAD_CROP_BITMAP). */
1429 /* */
1430 /* stream :: The input stream. */
1431 /* */
1432 /* <Output> */
1433 /* map :: The target pixmap. */
1434 /* */
1435 /* metrics :: A big sbit metrics structure for the glyph image. */
1436 /* */
1437 /* <Return> */
1438 /* FreeType error code. 0 means success. Returns an error if no */
1439 /* glyph sbit exists for the index. */
1440 /* */
1441 /* <Note> */
1442 /* The `map.buffer' field is always freed before the glyph is loaded. */
1443 /* */
1444 FT_LOCAL_DEF( FT_Error )
1445 tt_face_load_sbit_image( TT_Face face,
1446 FT_ULong strike_index,
1447 FT_UInt glyph_index,
1448 FT_UInt load_flags,
1449 FT_Stream stream,
1450 FT_Bitmap *map,
1451 TT_SBit_MetricsRec *metrics )
1452 {
1453 FT_Error error;
1454 FT_ULong ebdt_pos, glyph_offset;
1455
1456 TT_SBit_Strike strike;
1457 TT_SBit_Range range;
1458
1459
1460 /* Check whether there is a glyph sbit for the current index */
1461 error = tt_find_sbit_image( face, glyph_index, strike_index,
1462 &range, &strike, &glyph_offset );
1463 if ( error )
1464 goto Exit;
1465
1466 /* now, find the location of the `EBDT' table in */
1467 /* the font file */
1468 error = face->goto_table( face, TTAG_EBDT, stream, 0 );
1469 if ( error )
1470 error = face->goto_table( face, TTAG_bdat, stream, 0 );
1471 if ( error )
1472 goto Exit;
1473
1474 ebdt_pos = FT_STREAM_POS();
1475
1476 error = Load_SBit_Image( strike, range, ebdt_pos, glyph_offset,
1477 face->root.glyph, 0, 0, stream, metrics, 0 );
1478 if ( error )
1479 goto Exit;
1480
1481 /* setup vertical metrics if needed */
1482 if ( strike->flags & 1 )
1483 {
1484 /* in case of a horizontal strike only */
1485 FT_Int advance;
1486
1487
1488 advance = strike->hori.ascender - strike->hori.descender;
1489
1490 /* some heuristic values */
1491
1492 metrics->vertBearingX = (FT_Char)(-metrics->width / 2 );
1493 metrics->vertBearingY = (FT_Char)( ( advance - metrics->height ) / 2 );
1494 metrics->vertAdvance = (FT_Char)( advance * 12 / 10 );
1495 }
1496
1497 /* Crop the bitmap now, unless specified otherwise */
1498 if ( load_flags & FT_LOAD_CROP_BITMAP )
1499 crop_bitmap( map, metrics );
1500
1501 Exit:
1502 return error;
1503 }
1504
1505 #endif /* FT_CONFIG_OPTION_OLD_INTERNALS */
1506
1507
1508 /* END */
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