Edit
kc3-lang/freetype/src/sfnt/ttsbit0.c
Werner Lemberg
- src/sfnt/ttsbit0.c
-
/***************************************************************************/ /* */ /* ttsbit0.c */ /* */ /* TrueType and OpenType embedded bitmap support (body). */ /* This is a heap-optimized version. */ /* */ /* Copyright 2005, 2006, 2007, 2008, 2009 by */ /* David Turner, Robert Wilhelm, and Werner Lemberg. */ /* */ /* This file is part of the FreeType project, and may only be used, */ /* modified, and distributed under the terms of the FreeType project */ /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ /* this file you indicate that you have read the license and */ /* understand and accept it fully. */ /* */ /***************************************************************************/ /* This file is included by ttsbit.c */ #include <ft2build.h> #include FT_INTERNAL_DEBUG_H #include FT_INTERNAL_STREAM_H #include FT_TRUETYPE_TAGS_H #include "ttsbit.h" #include "sferrors.h" /*************************************************************************/ /* */ /* The macro FT_COMPONENT is used in trace mode. It is an implicit */ /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */ /* messages during execution. */ /* */ #undef FT_COMPONENT #define FT_COMPONENT trace_ttsbit FT_LOCAL_DEF( FT_Error ) tt_face_load_eblc( TT_Face face, FT_Stream stream ) { FT_Error error = SFNT_Err_Ok; FT_Fixed version; FT_ULong num_strikes, table_size; FT_Byte* p; FT_Byte* p_limit; FT_UInt count; face->sbit_num_strikes = 0; /* this table is optional */ error = face->goto_table( face, TTAG_EBLC, stream, &table_size ); if ( error ) error = face->goto_table( face, TTAG_bloc, stream, &table_size ); if ( error ) goto Exit; if ( table_size < 8 ) { FT_ERROR(( "tt_face_load_sbit_strikes: table too short\n" )); error = SFNT_Err_Invalid_File_Format; goto Exit; } if ( FT_FRAME_EXTRACT( table_size, face->sbit_table ) ) goto Exit; face->sbit_table_size = table_size; p = face->sbit_table; p_limit = p + table_size; version = FT_NEXT_ULONG( p ); num_strikes = FT_NEXT_ULONG( p ); if ( version != 0x00020000UL || num_strikes >= 0x10000UL ) { FT_ERROR(( "tt_face_load_sbit_strikes: invalid table version\n" )); error = SFNT_Err_Invalid_File_Format; goto Fail; } /* * Count the number of strikes available in the table. We are a bit * paranoid there and don't trust the data. */ count = (FT_UInt)num_strikes; if ( 8 + 48UL * count > table_size ) count = (FT_UInt)( ( p_limit - p ) / 48 ); face->sbit_num_strikes = count; FT_TRACE3(( "sbit_num_strikes: %u\n", count )); Exit: return error; Fail: FT_FRAME_RELEASE( face->sbit_table ); face->sbit_table_size = 0; goto Exit; } FT_LOCAL_DEF( void ) tt_face_free_eblc( TT_Face face ) { FT_Stream stream = face->root.stream; FT_FRAME_RELEASE( face->sbit_table ); face->sbit_table_size = 0; face->sbit_num_strikes = 0; } FT_LOCAL_DEF( FT_Error ) tt_face_set_sbit_strike( TT_Face face, FT_Size_Request req, FT_ULong* astrike_index ) { return FT_Match_Size( (FT_Face)face, req, 0, astrike_index ); } FT_LOCAL_DEF( FT_Error ) tt_face_load_strike_metrics( TT_Face face, FT_ULong strike_index, FT_Size_Metrics* metrics ) { FT_Byte* strike; if ( strike_index >= (FT_ULong)face->sbit_num_strikes ) return SFNT_Err_Invalid_Argument; strike = face->sbit_table + 8 + strike_index * 48; metrics->x_ppem = (FT_UShort)strike[44]; metrics->y_ppem = (FT_UShort)strike[45]; metrics->ascender = (FT_Char)strike[16] << 6; /* hori.ascender */ metrics->descender = (FT_Char)strike[17] << 6; /* hori.descender */ metrics->height = metrics->ascender - metrics->descender; /* XXX: Is this correct? */ metrics->max_advance = ( (FT_Char)strike[22] + /* min_origin_SB */ strike[18] + /* max_width */ (FT_Char)strike[23] /* min_advance_SB */ ) << 6; return SFNT_Err_Ok; } typedef struct TT_SBitDecoderRec_ { TT_Face face; FT_Stream stream; FT_Bitmap* bitmap; TT_SBit_Metrics metrics; FT_Bool metrics_loaded; FT_Bool bitmap_allocated; FT_Byte bit_depth; FT_ULong ebdt_start; FT_ULong ebdt_size; FT_ULong strike_index_array; FT_ULong strike_index_count; FT_Byte* eblc_base; FT_Byte* eblc_limit; } TT_SBitDecoderRec, *TT_SBitDecoder; static FT_Error tt_sbit_decoder_init( TT_SBitDecoder decoder, TT_Face face, FT_ULong strike_index, TT_SBit_MetricsRec* metrics ) { FT_Error error; FT_Stream stream = face->root.stream; FT_ULong ebdt_size; error = face->goto_table( face, TTAG_EBDT, stream, &ebdt_size ); if ( error ) error = face->goto_table( face, TTAG_bdat, stream, &ebdt_size ); if ( error ) goto Exit; decoder->face = face; decoder->stream = stream; decoder->bitmap = &face->root.glyph->bitmap; decoder->metrics = metrics; decoder->metrics_loaded = 0; decoder->bitmap_allocated = 0; decoder->ebdt_start = FT_STREAM_POS(); decoder->ebdt_size = ebdt_size; decoder->eblc_base = face->sbit_table; decoder->eblc_limit = face->sbit_table + face->sbit_table_size; /* now find the strike corresponding to the index */ { FT_Byte* p; if ( 8 + 48 * strike_index + 3 * 4 + 34 + 1 > face->sbit_table_size ) { error = SFNT_Err_Invalid_File_Format; goto Exit; } p = decoder->eblc_base + 8 + 48 * strike_index; decoder->strike_index_array = FT_NEXT_ULONG( p ); p += 4; decoder->strike_index_count = FT_NEXT_ULONG( p ); p += 34; decoder->bit_depth = *p; if ( decoder->strike_index_array > face->sbit_table_size || decoder->strike_index_array + 8 * decoder->strike_index_count > face->sbit_table_size ) error = SFNT_Err_Invalid_File_Format; } Exit: return error; } static void tt_sbit_decoder_done( TT_SBitDecoder decoder ) { FT_UNUSED( decoder ); } static FT_Error tt_sbit_decoder_alloc_bitmap( TT_SBitDecoder decoder ) { FT_Error error = SFNT_Err_Ok; FT_UInt width, height; FT_Bitmap* map = decoder->bitmap; FT_Long size; if ( !decoder->metrics_loaded ) { error = SFNT_Err_Invalid_Argument; goto Exit; } width = decoder->metrics->width; height = decoder->metrics->height; map->width = (int)width; map->rows = (int)height; switch ( decoder->bit_depth ) { case 1: map->pixel_mode = FT_PIXEL_MODE_MONO; map->pitch = ( map->width + 7 ) >> 3; break; case 2: map->pixel_mode = FT_PIXEL_MODE_GRAY2; map->pitch = ( map->width + 3 ) >> 2; break; case 4: map->pixel_mode = FT_PIXEL_MODE_GRAY4; map->pitch = ( map->width + 1 ) >> 1; break; case 8: map->pixel_mode = FT_PIXEL_MODE_GRAY; map->pitch = map->width; break; default: error = SFNT_Err_Invalid_File_Format; goto Exit; } size = map->rows * map->pitch; /* check that there is no empty image */ if ( size == 0 ) goto Exit; /* exit successfully! */ error = ft_glyphslot_alloc_bitmap( decoder->face->root.glyph, size ); if ( error ) goto Exit; decoder->bitmap_allocated = 1; Exit: return error; } static FT_Error tt_sbit_decoder_load_metrics( TT_SBitDecoder decoder, FT_Byte* *pp, FT_Byte* limit, FT_Bool big ) { FT_Byte* p = *pp; TT_SBit_Metrics metrics = decoder->metrics; if ( p + 5 > limit ) goto Fail; metrics->height = p[0]; metrics->width = p[1]; metrics->horiBearingX = (FT_Char)p[2]; metrics->horiBearingY = (FT_Char)p[3]; metrics->horiAdvance = p[4]; p += 5; if ( big ) { if ( p + 3 > limit ) goto Fail; metrics->vertBearingX = (FT_Char)p[0]; metrics->vertBearingY = (FT_Char)p[1]; metrics->vertAdvance = p[2]; p += 3; } decoder->metrics_loaded = 1; *pp = p; return SFNT_Err_Ok; Fail: return SFNT_Err_Invalid_Argument; } /* forward declaration */ static FT_Error tt_sbit_decoder_load_image( TT_SBitDecoder decoder, FT_UInt glyph_index, FT_Int x_pos, FT_Int y_pos ); typedef FT_Error (*TT_SBitDecoder_LoadFunc)( TT_SBitDecoder decoder, FT_Byte* p, FT_Byte* plimit, FT_Int x_pos, FT_Int y_pos ); static FT_Error tt_sbit_decoder_load_byte_aligned( TT_SBitDecoder decoder, FT_Byte* p, FT_Byte* limit, FT_Int x_pos, FT_Int y_pos ) { FT_Error error = SFNT_Err_Ok; FT_Byte* line; FT_Int bit_height, bit_width, pitch, width, height, h; FT_Bitmap* bitmap; if ( !decoder->bitmap_allocated ) { error = tt_sbit_decoder_alloc_bitmap( decoder ); if ( error ) goto Exit; } /* check that we can write the glyph into the bitmap */ bitmap = decoder->bitmap; bit_width = bitmap->width; bit_height = bitmap->rows; pitch = bitmap->pitch; line = bitmap->buffer; width = decoder->metrics->width; height = decoder->metrics->height; if ( x_pos < 0 || x_pos + width > bit_width || y_pos < 0 || y_pos + height > bit_height ) { error = SFNT_Err_Invalid_File_Format; goto Exit; } if ( p + ( ( width + 7 ) >> 3 ) * height > limit ) { error = SFNT_Err_Invalid_File_Format; goto Exit; } /* now do the blit */ line += y_pos * pitch + ( x_pos >> 3 ); x_pos &= 7; if ( x_pos == 0 ) /* the easy one */ { for ( h = height; h > 0; h--, line += pitch ) { FT_Byte* write = line; FT_Int w; for ( w = width; w >= 8; w -= 8 ) { write[0] = (FT_Byte)( write[0] | *p++ ); write += 1; } if ( w > 0 ) write[0] = (FT_Byte)( write[0] | ( *p++ & ( 0xFF00U >> w ) ) ); } } else /* x_pos > 0 */ { for ( h = height; h > 0; h--, line += pitch ) { FT_Byte* write = line; FT_Int w; FT_UInt wval = 0; for ( w = width; w >= 8; w -= 8 ) { wval = (FT_UInt)( wval | *p++ ); write[0] = (FT_Byte)( write[0] | ( wval >> x_pos ) ); write += 1; wval <<= 8; } if ( w > 0 ) wval = (FT_UInt)( wval | ( *p++ & ( 0xFF00U >> w ) ) ); /* all bits read and there are `x_pos + w' bits to be written */ write[0] = (FT_Byte)( write[0] | ( wval >> x_pos ) ); if ( x_pos + w > 8 ) { write++; wval <<= 8; write[0] = (FT_Byte)( write[0] | ( wval >> x_pos ) ); } } } Exit: return error; } /* * Load a bit-aligned bitmap (with pointer `p') into a line-aligned bitmap * (with pointer `write'). In the example below, the width is 3 pixel, * and `x_pos' is 1 pixel. * * p p+1 * | | | * | 7 6 5 4 3 2 1 0 | 7 6 5 4 3 2 1 0 |... * | | | * +-------+ +-------+ +-------+ ... * . . . * . . . * v . . * +-------+ . . * | | . * | 7 6 5 4 3 2 1 0 | . * | | . * write . . * . . * v . * +-------+ . * | | * | 7 6 5 4 3 2 1 0 | * | | * write+1 . * . * v * +-------+ * | | * | 7 6 5 4 3 2 1 0 | * | | * write+2 * */ static FT_Error tt_sbit_decoder_load_bit_aligned( TT_SBitDecoder decoder, FT_Byte* p, FT_Byte* limit, FT_Int x_pos, FT_Int y_pos ) { FT_Error error = SFNT_Err_Ok; FT_Byte* line; FT_Int bit_height, bit_width, pitch, width, height, h, nbits; FT_Bitmap* bitmap; FT_UShort rval; if ( !decoder->bitmap_allocated ) { error = tt_sbit_decoder_alloc_bitmap( decoder ); if ( error ) goto Exit; } /* check that we can write the glyph into the bitmap */ bitmap = decoder->bitmap; bit_width = bitmap->width; bit_height = bitmap->rows; pitch = bitmap->pitch; line = bitmap->buffer; width = decoder->metrics->width; height = decoder->metrics->height; if ( x_pos < 0 || x_pos + width > bit_width || y_pos < 0 || y_pos + height > bit_height ) { error = SFNT_Err_Invalid_File_Format; goto Exit; } if ( p + ( ( width * height + 7 ) >> 3 ) > limit ) { error = SFNT_Err_Invalid_File_Format; goto Exit; } /* now do the blit */ /* adjust `line' to point to the first byte of the bitmap */ line += y_pos * pitch + ( x_pos >> 3 ); x_pos &= 7; /* the higher byte of `rval' is used as a buffer */ rval = 0; nbits = 0; for ( h = height; h > 0; h--, line += pitch ) { FT_Byte* write = line; FT_Int w = width; /* handle initial byte (in target bitmap) specially if necessary */ if ( x_pos ) { w = ( width < 8 - x_pos ) ? width : 8 - x_pos; if ( h == height ) { rval = *p++; nbits = x_pos; } else if ( nbits < w ) { if ( p < limit ) rval |= *p++; nbits += 8 - w; } else { rval >>= 8; nbits -= w; } *write++ |= ( ( rval >> nbits ) & 0xFF ) & ( ~( 0xFF << w ) << ( 8 - w - x_pos ) ); rval <<= 8; w = width - w; } /* handle medial bytes */ for ( ; w >= 8; w -= 8 ) { rval |= *p++; *write++ |= ( rval >> nbits ) & 0xFF; rval <<= 8; } /* handle final byte if necessary */ if ( w > 0 ) { if ( nbits < w ) { if ( p < limit ) rval |= *p++; *write |= ( ( rval >> nbits ) & 0xFF ) & ( 0xFF00U >> w ); nbits += 8 - w; rval <<= 8; } else { *write |= ( ( rval >> nbits ) & 0xFF ) & ( 0xFF00U >> w ); nbits -= w; } } } Exit: return error; } static FT_Error tt_sbit_decoder_load_compound( TT_SBitDecoder decoder, FT_Byte* p, FT_Byte* limit, FT_Int x_pos, FT_Int y_pos ) { FT_Error error = SFNT_Err_Ok; FT_UInt num_components, nn; FT_Char horiBearingX = decoder->metrics->horiBearingX; FT_Char horiBearingY = decoder->metrics->horiBearingY; FT_Byte horiAdvance = decoder->metrics->horiAdvance; FT_Char vertBearingX = decoder->metrics->vertBearingX; FT_Char vertBearingY = decoder->metrics->vertBearingY; FT_Byte vertAdvance = decoder->metrics->vertAdvance; if ( p + 2 > limit ) goto Fail; num_components = FT_NEXT_USHORT( p ); if ( p + 4 * num_components > limit ) goto Fail; if ( !decoder->bitmap_allocated ) { error = tt_sbit_decoder_alloc_bitmap( decoder ); if ( error ) goto Exit; } for ( nn = 0; nn < num_components; nn++ ) { FT_UInt gindex = FT_NEXT_USHORT( p ); FT_Byte dx = FT_NEXT_BYTE( p ); FT_Byte dy = FT_NEXT_BYTE( p ); /* NB: a recursive call */ error = tt_sbit_decoder_load_image( decoder, gindex, x_pos + dx, y_pos + dy ); if ( error ) break; } decoder->metrics->horiBearingX = horiBearingX; decoder->metrics->horiBearingY = horiBearingY; decoder->metrics->horiAdvance = horiAdvance; decoder->metrics->vertBearingX = vertBearingX; decoder->metrics->vertBearingY = vertBearingY; decoder->metrics->vertAdvance = vertAdvance; decoder->metrics->width = (FT_UInt)decoder->bitmap->width; decoder->metrics->height = (FT_UInt)decoder->bitmap->rows; Exit: return error; Fail: error = SFNT_Err_Invalid_File_Format; goto Exit; } static FT_Error tt_sbit_decoder_load_bitmap( TT_SBitDecoder decoder, FT_UInt glyph_format, FT_ULong glyph_start, FT_ULong glyph_size, FT_Int x_pos, FT_Int y_pos ) { FT_Error error; FT_Stream stream = decoder->stream; FT_Byte* p; FT_Byte* p_limit; FT_Byte* data; /* seek into the EBDT table now */ if ( glyph_start + glyph_size > decoder->ebdt_size ) { error = SFNT_Err_Invalid_Argument; goto Exit; } if ( FT_STREAM_SEEK( decoder->ebdt_start + glyph_start ) || FT_FRAME_EXTRACT( glyph_size, data ) ) goto Exit; p = data; p_limit = p + glyph_size; /* read the data, depending on the glyph format */ switch ( glyph_format ) { case 1: case 2: case 8: error = tt_sbit_decoder_load_metrics( decoder, &p, p_limit, 0 ); break; case 6: case 7: case 9: error = tt_sbit_decoder_load_metrics( decoder, &p, p_limit, 1 ); break; default: error = SFNT_Err_Ok; } if ( error ) goto Fail; { TT_SBitDecoder_LoadFunc loader; switch ( glyph_format ) { case 1: case 6: loader = tt_sbit_decoder_load_byte_aligned; break; case 2: case 5: case 7: loader = tt_sbit_decoder_load_bit_aligned; break; case 8: if ( p + 1 > p_limit ) goto Fail; p += 1; /* skip padding */ /* fall-through */ case 9: loader = tt_sbit_decoder_load_compound; break; default: goto Fail; } error = loader( decoder, p, p_limit, x_pos, y_pos ); } Fail: FT_FRAME_RELEASE( data ); Exit: return error; } static FT_Error tt_sbit_decoder_load_image( TT_SBitDecoder decoder, FT_UInt glyph_index, FT_Int x_pos, FT_Int y_pos ) { /* * First, we find the correct strike range that applies to this * glyph index. */ FT_Byte* p = decoder->eblc_base + decoder->strike_index_array; FT_Byte* p_limit = decoder->eblc_limit; FT_ULong num_ranges = decoder->strike_index_count; FT_UInt start, end, index_format, image_format; FT_ULong image_start = 0, image_end = 0, image_offset; for ( ; num_ranges > 0; num_ranges-- ) { start = FT_NEXT_USHORT( p ); end = FT_NEXT_USHORT( p ); if ( glyph_index >= start && glyph_index <= end ) goto FoundRange; p += 4; /* ignore index offset */ } goto NoBitmap; FoundRange: image_offset = FT_NEXT_ULONG( p ); /* overflow check */ if ( decoder->eblc_base + decoder->strike_index_array + image_offset < decoder->eblc_base ) goto Failure; p = decoder->eblc_base + decoder->strike_index_array + image_offset; if ( p + 8 > p_limit ) goto NoBitmap; /* now find the glyph's location and extend within the ebdt table */ index_format = FT_NEXT_USHORT( p ); image_format = FT_NEXT_USHORT( p ); image_offset = FT_NEXT_ULONG ( p ); switch ( index_format ) { case 1: /* 4-byte offsets relative to `image_offset' */ { p += 4 * ( glyph_index - start ); if ( p + 8 > p_limit ) goto NoBitmap; image_start = FT_NEXT_ULONG( p ); image_end = FT_NEXT_ULONG( p ); if ( image_start == image_end ) /* missing glyph */ goto NoBitmap; } break; case 2: /* big metrics, constant image size */ { FT_ULong image_size; if ( p + 12 > p_limit ) goto NoBitmap; image_size = FT_NEXT_ULONG( p ); if ( tt_sbit_decoder_load_metrics( decoder, &p, p_limit, 1 ) ) goto NoBitmap; image_start = image_size * ( glyph_index - start ); image_end = image_start + image_size; } break; case 3: /* 2-byte offsets relative to 'image_offset' */ { p += 2 * ( glyph_index - start ); if ( p + 4 > p_limit ) goto NoBitmap; image_start = FT_NEXT_USHORT( p ); image_end = FT_NEXT_USHORT( p ); if ( image_start == image_end ) /* missing glyph */ goto NoBitmap; } break; case 4: /* sparse glyph array with (glyph,offset) pairs */ { FT_ULong mm, num_glyphs; if ( p + 4 > p_limit ) goto NoBitmap; num_glyphs = FT_NEXT_ULONG( p ); /* overflow check */ if ( p + ( num_glyphs + 1 ) * 4 < p ) goto Failure; if ( p + ( num_glyphs + 1 ) * 4 > p_limit ) goto NoBitmap; for ( mm = 0; mm < num_glyphs; mm++ ) { FT_UInt gindex = FT_NEXT_USHORT( p ); if ( gindex == glyph_index ) { image_start = FT_NEXT_USHORT( p ); p += 2; image_end = FT_PEEK_USHORT( p ); break; } p += 2; } if ( mm >= num_glyphs ) goto NoBitmap; } break; case 5: /* constant metrics with sparse glyph codes */ { FT_ULong image_size, mm, num_glyphs; if ( p + 16 > p_limit ) goto NoBitmap; image_size = FT_NEXT_ULONG( p ); if ( tt_sbit_decoder_load_metrics( decoder, &p, p_limit, 1 ) ) goto NoBitmap; num_glyphs = FT_NEXT_ULONG( p ); /* overflow check */ if ( p + 2 * num_glyphs < p ) goto Failure; if ( p + 2 * num_glyphs > p_limit ) goto NoBitmap; for ( mm = 0; mm < num_glyphs; mm++ ) { FT_UInt gindex = FT_NEXT_USHORT( p ); if ( gindex == glyph_index ) break; } if ( mm >= num_glyphs ) goto NoBitmap; image_start = image_size * mm; image_end = image_start + image_size; } break; default: goto NoBitmap; } if ( image_start > image_end ) goto NoBitmap; image_end -= image_start; image_start = image_offset + image_start; return tt_sbit_decoder_load_bitmap( decoder, image_format, image_start, image_end, x_pos, y_pos ); Failure: return SFNT_Err_Invalid_Table; NoBitmap: return SFNT_Err_Invalid_Argument; } FT_LOCAL( FT_Error ) tt_face_load_sbit_image( TT_Face face, FT_ULong strike_index, FT_UInt glyph_index, FT_UInt load_flags, FT_Stream stream, FT_Bitmap *map, TT_SBit_MetricsRec *metrics ) { TT_SBitDecoderRec decoder[1]; FT_Error error; FT_UNUSED( load_flags ); FT_UNUSED( stream ); FT_UNUSED( map ); error = tt_sbit_decoder_init( decoder, face, strike_index, metrics ); if ( !error ) { error = tt_sbit_decoder_load_image( decoder, glyph_index, 0, 0 ); tt_sbit_decoder_done( decoder ); } return error; } /* EOF */