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