Edit
kc3-lang/freetype/src/sfnt/ttsbit.c
Werner Lemberg
- src/sfnt/ttsbit.c
-
/***************************************************************************/ /* */ /* ttsbit.c */ /* */ /* TrueType and OpenType embedded bitmap support (body). */ /* */ /* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, */ /* 2010 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. */ /* */ /***************************************************************************/ #include <ft2build.h> #include FT_INTERNAL_DEBUG_H #include FT_INTERNAL_STREAM_H #include FT_TRUETYPE_TAGS_H /* * Alas, the memory-optimized sbit loader can't be used when implementing * the `old internals' hack */ #ifndef FT_CONFIG_OPTION_OLD_INTERNALS #include "ttsbit0.c" #else /* FT_CONFIG_OPTION_OLD_INTERNALS */ #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 /*************************************************************************/ /* */ /* <Function> */ /* blit_sbit */ /* */ /* <Description> */ /* Blits a bitmap from an input stream into a given target. Supports */ /* x and y offsets as well as byte padded lines. */ /* */ /* <Input> */ /* target :: The target bitmap/pixmap. */ /* */ /* source :: The input packed bitmap data. */ /* */ /* line_bits :: The number of bits per line. */ /* */ /* byte_padded :: A flag which is true if lines are byte-padded. */ /* */ /* x_offset :: The horizontal offset. */ /* */ /* y_offset :: The vertical offset. */ /* */ /* <Note> */ /* IMPORTANT: The x and y offsets are relative to the top corner of */ /* the target bitmap (unlike the normal TrueType */ /* convention). A positive y offset indicates a downwards */ /* direction! */ /* */ static void blit_sbit( FT_Bitmap* target, FT_Byte* source, FT_Int line_bits, FT_Bool byte_padded, FT_Int x_offset, FT_Int y_offset, FT_Int source_height ) { FT_Byte* line_buff; FT_Int line_incr; FT_Int height; FT_UShort acc; FT_UInt loaded; /* first of all, compute starting write position */ line_incr = target->pitch; line_buff = target->buffer; if ( line_incr < 0 ) line_buff -= line_incr * ( target->rows - 1 ); line_buff += ( x_offset >> 3 ) + y_offset * line_incr; /***********************************************************************/ /* */ /* We use the extra-classic `accumulator' trick to extract the bits */ /* from the source byte stream. */ /* */ /* Namely, the variable `acc' is a 16-bit accumulator containing the */ /* last `loaded' bits from the input stream. The bits are shifted to */ /* the upmost position in `acc'. */ /* */ /***********************************************************************/ acc = 0; /* clear accumulator */ loaded = 0; /* no bits were loaded */ for ( height = source_height; height > 0; height-- ) { FT_Byte* cur = line_buff; /* current write cursor */ FT_Int count = line_bits; /* # of bits to extract per line */ FT_Byte shift = (FT_Byte)( x_offset & 7 ); /* current write shift */ FT_Byte space = (FT_Byte)( 8 - shift ); /* first of all, read individual source bytes */ if ( count >= 8 ) { count -= 8; { do { FT_Byte val; /* ensure that there are at least 8 bits in the accumulator */ if ( loaded < 8 ) { acc |= (FT_UShort)((FT_UShort)*source++ << ( 8 - loaded )); loaded += 8; } /* now write one byte */ val = (FT_Byte)( acc >> 8 ); if ( shift ) { cur[0] |= (FT_Byte)( val >> shift ); cur[1] |= (FT_Byte)( val << space ); } else cur[0] |= val; cur++; acc <<= 8; /* remove bits from accumulator */ loaded -= 8; count -= 8; } while ( count >= 0 ); } /* restore `count' to correct value */ count += 8; } /* now write remaining bits (count < 8) */ if ( count > 0 ) { FT_Byte val; /* ensure that there are at least `count' bits in the accumulator */ if ( (FT_Int)loaded < count ) { acc |= (FT_UShort)((FT_UShort)*source++ << ( 8 - loaded )); loaded += 8; } /* now write remaining bits */ val = (FT_Byte)( ( (FT_Byte)( acc >> 8 ) ) & ~( 0xFF >> count ) ); cur[0] |= (FT_Byte)( val >> shift ); if ( count > space ) cur[1] |= (FT_Byte)( val << space ); acc <<= count; loaded -= count; } /* now, skip to next line */ if ( byte_padded ) { acc = 0; loaded = 0; /* clear accumulator on byte-padded lines */ } line_buff += line_incr; } } static const FT_Frame_Field sbit_metrics_fields[] = { #undef FT_STRUCTURE #define FT_STRUCTURE TT_SBit_MetricsRec FT_FRAME_START( 8 ), FT_FRAME_BYTE( height ), FT_FRAME_BYTE( width ), FT_FRAME_CHAR( horiBearingX ), FT_FRAME_CHAR( horiBearingY ), FT_FRAME_BYTE( horiAdvance ), FT_FRAME_CHAR( vertBearingX ), FT_FRAME_CHAR( vertBearingY ), FT_FRAME_BYTE( vertAdvance ), FT_FRAME_END }; /*************************************************************************/ /* */ /* <Function> */ /* Load_SBit_Const_Metrics */ /* */ /* <Description> */ /* Loads the metrics for `EBLC' index tables format 2 and 5. */ /* */ /* <Input> */ /* range :: The target range. */ /* */ /* stream :: The input stream. */ /* */ /* <Return> */ /* FreeType error code. 0 means success. */ /* */ static FT_Error Load_SBit_Const_Metrics( TT_SBit_Range range, FT_Stream stream ) { FT_Error error; if ( FT_READ_ULONG( range->image_size ) ) return error; return FT_STREAM_READ_FIELDS( sbit_metrics_fields, &range->metrics ); } /*************************************************************************/ /* */ /* <Function> */ /* Load_SBit_Range_Codes */ /* */ /* <Description> */ /* Loads the range codes for `EBLC' index tables format 4 and 5. */ /* */ /* <Input> */ /* range :: The target range. */ /* */ /* stream :: The input stream. */ /* */ /* load_offsets :: A flag whether to load the glyph offset table. */ /* */ /* <Return> */ /* FreeType error code. 0 means success. */ /* */ static FT_Error Load_SBit_Range_Codes( TT_SBit_Range range, FT_Stream stream, FT_Bool load_offsets ) { FT_Error error; FT_ULong count, n, size; FT_Memory memory = stream->memory; if ( FT_READ_ULONG( count ) ) goto Exit; range->num_glyphs = count; /* Allocate glyph offsets table if needed */ if ( load_offsets ) { if ( FT_NEW_ARRAY( range->glyph_offsets, count ) ) goto Exit; size = count * 4L; } else size = count * 2L; /* Allocate glyph codes table and access frame */ if ( FT_NEW_ARRAY ( range->glyph_codes, count ) || FT_FRAME_ENTER( size ) ) goto Exit; for ( n = 0; n < count; n++ ) { range->glyph_codes[n] = FT_GET_USHORT(); if ( load_offsets ) range->glyph_offsets[n] = (FT_ULong)range->image_offset + FT_GET_USHORT(); } FT_FRAME_EXIT(); Exit: return error; } /*************************************************************************/ /* */ /* <Function> */ /* Load_SBit_Range */ /* */ /* <Description> */ /* Loads a given `EBLC' index/range table. */ /* */ /* <Input> */ /* range :: The target range. */ /* */ /* stream :: The input stream. */ /* */ /* <Return> */ /* FreeType error code. 0 means success. */ /* */ static FT_Error Load_SBit_Range( TT_SBit_Range range, FT_Stream stream ) { FT_Error error; FT_Memory memory = stream->memory; switch( range->index_format ) { case 1: /* variable metrics with 4-byte offsets */ case 3: /* variable metrics with 2-byte offsets */ { FT_ULong num_glyphs, n; FT_Int size_elem; FT_Bool large = FT_BOOL( range->index_format == 1 ); if ( range->last_glyph < range->first_glyph ) { error = SFNT_Err_Invalid_File_Format; goto Exit; } num_glyphs = range->last_glyph - range->first_glyph + 1L; range->num_glyphs = num_glyphs; num_glyphs++; /* XXX: BEWARE - see spec */ size_elem = large ? 4 : 2; if ( FT_NEW_ARRAY( range->glyph_offsets, num_glyphs ) || FT_FRAME_ENTER( num_glyphs * size_elem ) ) goto Exit; for ( n = 0; n < num_glyphs; n++ ) range->glyph_offsets[n] = (FT_ULong)( range->image_offset + ( large ? FT_GET_ULONG() : FT_GET_USHORT() ) ); FT_FRAME_EXIT(); } break; case 2: /* all glyphs have identical metrics */ error = Load_SBit_Const_Metrics( range, stream ); break; case 4: error = Load_SBit_Range_Codes( range, stream, 1 ); break; case 5: error = Load_SBit_Const_Metrics( range, stream ); if ( !error ) error = Load_SBit_Range_Codes( range, stream, 0 ); break; default: error = SFNT_Err_Invalid_File_Format; } Exit: return error; } /*************************************************************************/ /* */ /* <Function> */ /* tt_face_load_eblc */ /* */ /* <Description> */ /* Loads the table of embedded bitmap sizes for this face. */ /* */ /* <Input> */ /* face :: The target face object. */ /* */ /* stream :: The input stream. */ /* */ /* <Return> */ /* FreeType error code. 0 means success. */ /* */ FT_LOCAL_DEF( FT_Error ) tt_face_load_eblc( TT_Face face, FT_Stream stream ) { FT_Error error = SFNT_Err_Ok; FT_Memory memory = stream->memory; FT_Fixed version; FT_ULong num_strikes; FT_ULong table_base; static const FT_Frame_Field sbit_line_metrics_fields[] = { #undef FT_STRUCTURE #define FT_STRUCTURE TT_SBit_LineMetricsRec /* no FT_FRAME_START */ FT_FRAME_CHAR( ascender ), FT_FRAME_CHAR( descender ), FT_FRAME_BYTE( max_width ), FT_FRAME_CHAR( caret_slope_numerator ), FT_FRAME_CHAR( caret_slope_denominator ), FT_FRAME_CHAR( caret_offset ), FT_FRAME_CHAR( min_origin_SB ), FT_FRAME_CHAR( min_advance_SB ), FT_FRAME_CHAR( max_before_BL ), FT_FRAME_CHAR( min_after_BL ), FT_FRAME_CHAR( pads[0] ), FT_FRAME_CHAR( pads[1] ), FT_FRAME_END }; static const FT_Frame_Field strike_start_fields[] = { #undef FT_STRUCTURE #define FT_STRUCTURE TT_SBit_StrikeRec /* no FT_FRAME_START */ FT_FRAME_ULONG( ranges_offset ), FT_FRAME_SKIP_LONG, FT_FRAME_ULONG( num_ranges ), FT_FRAME_ULONG( color_ref ), FT_FRAME_END }; static const FT_Frame_Field strike_end_fields[] = { /* no FT_FRAME_START */ FT_FRAME_USHORT( start_glyph ), FT_FRAME_USHORT( end_glyph ), FT_FRAME_BYTE ( x_ppem ), FT_FRAME_BYTE ( y_ppem ), FT_FRAME_BYTE ( bit_depth ), FT_FRAME_CHAR ( flags ), FT_FRAME_END }; face->num_sbit_strikes = 0; /* this table is optional */ error = face->goto_table( face, TTAG_EBLC, stream, 0 ); if ( error ) error = face->goto_table( face, TTAG_bloc, stream, 0 ); if ( error ) goto Exit; table_base = FT_STREAM_POS(); if ( FT_FRAME_ENTER( 8L ) ) goto Exit; version = FT_GET_LONG(); num_strikes = FT_GET_ULONG(); FT_FRAME_EXIT(); /* check version number and strike count */ if ( version != 0x00020000L || num_strikes >= 0x10000L ) { FT_ERROR(( "tt_face_load_sbit_strikes: invalid table version\n" )); error = SFNT_Err_Invalid_File_Format; goto Exit; } /* allocate the strikes table */ if ( FT_NEW_ARRAY( face->sbit_strikes, num_strikes ) ) goto Exit; face->num_sbit_strikes = num_strikes; /* now read each strike table separately */ { TT_SBit_Strike strike = face->sbit_strikes; FT_ULong count = num_strikes; if ( FT_FRAME_ENTER( 48L * num_strikes ) ) goto Exit; while ( count > 0 ) { if ( FT_STREAM_READ_FIELDS( strike_start_fields, strike ) || FT_STREAM_READ_FIELDS( sbit_line_metrics_fields, &strike->hori ) || FT_STREAM_READ_FIELDS( sbit_line_metrics_fields, &strike->vert ) || FT_STREAM_READ_FIELDS( strike_end_fields, strike ) ) break; count--; strike++; } FT_FRAME_EXIT(); } /* allocate the index ranges for each strike table */ { TT_SBit_Strike strike = face->sbit_strikes; FT_ULong count = num_strikes; while ( count > 0 ) { TT_SBit_Range range; FT_ULong count2 = strike->num_ranges; /* read each range */ if ( FT_STREAM_SEEK( table_base + strike->ranges_offset ) || FT_FRAME_ENTER( strike->num_ranges * 8L ) ) goto Exit; if ( FT_NEW_ARRAY( strike->sbit_ranges, strike->num_ranges ) ) goto Exit; range = strike->sbit_ranges; while ( count2 > 0 ) { range->first_glyph = FT_GET_USHORT(); range->last_glyph = FT_GET_USHORT(); range->table_offset = table_base + strike->ranges_offset + FT_GET_ULONG(); count2--; range++; } FT_FRAME_EXIT(); /* Now, read each index table */ count2 = strike->num_ranges; range = strike->sbit_ranges; while ( count2 > 0 ) { /* Read the header */ if ( FT_STREAM_SEEK( range->table_offset ) || FT_FRAME_ENTER( 8L ) ) goto Exit; range->index_format = FT_GET_USHORT(); range->image_format = FT_GET_USHORT(); range->image_offset = FT_GET_ULONG(); FT_FRAME_EXIT(); error = Load_SBit_Range( range, stream ); if ( error ) goto Exit; count2--; range++; } count--; strike++; } } Exit: return error; } /*************************************************************************/ /* */ /* <Function> */ /* tt_face_free_eblc */ /* */ /* <Description> */ /* Releases the embedded bitmap tables. */ /* */ /* <Input> */ /* face :: The target face object. */ /* */ FT_LOCAL_DEF( void ) tt_face_free_eblc( TT_Face face ) { FT_Memory memory = face->root.memory; TT_SBit_Strike strike = face->sbit_strikes; TT_SBit_Strike strike_limit = strike + face->num_sbit_strikes; if ( strike ) { for ( ; strike < strike_limit; strike++ ) { TT_SBit_Range range = strike->sbit_ranges; TT_SBit_Range range_limit = range + strike->num_ranges; if ( range ) { for ( ; range < range_limit; range++ ) { /* release the glyph offsets and codes tables */ /* where appropriate */ FT_FREE( range->glyph_offsets ); FT_FREE( range->glyph_codes ); } } FT_FREE( strike->sbit_ranges ); strike->num_ranges = 0; } FT_FREE( face->sbit_strikes ); } face->num_sbit_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 ) { TT_SBit_Strike strike; if ( strike_index >= face->num_sbit_strikes ) return SFNT_Err_Invalid_Argument; strike = face->sbit_strikes + strike_index; metrics->x_ppem = strike->x_ppem; metrics->y_ppem = strike->y_ppem; metrics->ascender = strike->hori.ascender << 6; metrics->descender = strike->hori.descender << 6; /* XXX: Is this correct? */ metrics->max_advance = ( strike->hori.min_origin_SB + strike->hori.max_width + strike->hori.min_advance_SB ) << 6; metrics->height = metrics->ascender - metrics->descender; return SFNT_Err_Ok; } /*************************************************************************/ /* */ /* <Function> */ /* find_sbit_range */ /* */ /* <Description> */ /* Scans a given strike's ranges and return, for a given glyph */ /* index, the corresponding sbit range, and `EBDT' offset. */ /* */ /* <Input> */ /* glyph_index :: The glyph index. */ /* */ /* strike :: The source/current sbit strike. */ /* */ /* <Output> */ /* arange :: The sbit range containing the glyph index. */ /* */ /* aglyph_offset :: The offset of the glyph data in `EBDT' table. */ /* */ /* <Return> */ /* FreeType error code. 0 means the glyph index was found. */ /* */ static FT_Error find_sbit_range( FT_UInt glyph_index, TT_SBit_Strike strike, TT_SBit_Range *arange, FT_ULong *aglyph_offset ) { TT_SBit_RangeRec *range, *range_limit; /* check whether the glyph index is within this strike's */ /* glyph range */ if ( glyph_index < (FT_UInt)strike->start_glyph || glyph_index > (FT_UInt)strike->end_glyph ) goto Fail; /* scan all ranges in strike */ range = strike->sbit_ranges; range_limit = range + strike->num_ranges; if ( !range ) goto Fail; for ( ; range < range_limit; range++ ) { if ( glyph_index >= (FT_UInt)range->first_glyph && glyph_index <= (FT_UInt)range->last_glyph ) { FT_UShort delta = (FT_UShort)( glyph_index - range->first_glyph ); switch ( range->index_format ) { case 1: case 3: *aglyph_offset = range->glyph_offsets[delta]; break; case 2: *aglyph_offset = range->image_offset + range->image_size * delta; break; case 4: case 5: { FT_ULong n; for ( n = 0; n < range->num_glyphs; n++ ) { if ( (FT_UInt)range->glyph_codes[n] == glyph_index ) { if ( range->index_format == 4 ) *aglyph_offset = range->glyph_offsets[n]; else *aglyph_offset = range->image_offset + n * range->image_size; goto Found; } } } /* fall-through */ default: goto Fail; } Found: /* return successfully! */ *arange = range; return SFNT_Err_Ok; } } Fail: *arange = 0; *aglyph_offset = 0; return SFNT_Err_Invalid_Argument; } /*************************************************************************/ /* */ /* <Function> */ /* tt_find_sbit_image */ /* */ /* <Description> */ /* Checks whether an embedded bitmap (an `sbit') exists for a given */ /* glyph, at a given strike. */ /* */ /* <Input> */ /* face :: The target face object. */ /* */ /* glyph_index :: The glyph index. */ /* */ /* strike_index :: The current strike index. */ /* */ /* <Output> */ /* arange :: The SBit range containing the glyph index. */ /* */ /* astrike :: The SBit strike containing the glyph index. */ /* */ /* aglyph_offset :: The offset of the glyph data in `EBDT' table. */ /* */ /* <Return> */ /* FreeType error code. 0 means success. Returns */ /* SFNT_Err_Invalid_Argument if no sbit exists for the requested */ /* glyph. */ /* */ FT_LOCAL( FT_Error ) tt_find_sbit_image( TT_Face face, FT_UInt glyph_index, FT_ULong strike_index, TT_SBit_Range *arange, TT_SBit_Strike *astrike, FT_ULong *aglyph_offset ) { FT_Error error; TT_SBit_Strike strike; if ( !face->sbit_strikes || ( face->num_sbit_strikes <= strike_index ) ) goto Fail; strike = &face->sbit_strikes[strike_index]; error = find_sbit_range( glyph_index, strike, arange, aglyph_offset ); if ( error ) goto Fail; *astrike = strike; return SFNT_Err_Ok; Fail: /* no embedded bitmap for this glyph in face */ *arange = 0; *astrike = 0; *aglyph_offset = 0; return SFNT_Err_Invalid_Argument; } /*************************************************************************/ /* */ /* <Function> */ /* tt_load_sbit_metrics */ /* */ /* <Description> */ /* Gets the big metrics for a given SBit. */ /* */ /* <Input> */ /* stream :: The input stream. */ /* */ /* range :: The SBit range containing the glyph. */ /* */ /* <Output> */ /* big_metrics :: A big SBit metrics structure for the glyph. */ /* */ /* <Return> */ /* FreeType error code. 0 means success. */ /* */ /* <Note> */ /* The stream cursor must be positioned at the glyph's offset within */ /* the `EBDT' table before the call. */ /* */ /* If the image format uses variable metrics, the stream cursor is */ /* positioned just after the metrics header in the `EBDT' table on */ /* function exit. */ /* */ FT_LOCAL( FT_Error ) tt_load_sbit_metrics( FT_Stream stream, TT_SBit_Range range, TT_SBit_Metrics metrics ) { FT_Error error = SFNT_Err_Ok; switch ( range->image_format ) { case 1: case 2: case 8: /* variable small metrics */ { TT_SBit_SmallMetricsRec smetrics; static const FT_Frame_Field sbit_small_metrics_fields[] = { #undef FT_STRUCTURE #define FT_STRUCTURE TT_SBit_SmallMetricsRec FT_FRAME_START( 5 ), FT_FRAME_BYTE( height ), FT_FRAME_BYTE( width ), FT_FRAME_CHAR( bearingX ), FT_FRAME_CHAR( bearingY ), FT_FRAME_BYTE( advance ), FT_FRAME_END }; /* read small metrics */ if ( FT_STREAM_READ_FIELDS( sbit_small_metrics_fields, &smetrics ) ) goto Exit; /* convert it to a big metrics */ metrics->height = smetrics.height; metrics->width = smetrics.width; metrics->horiBearingX = smetrics.bearingX; metrics->horiBearingY = smetrics.bearingY; metrics->horiAdvance = smetrics.advance; /* these metrics are made up at a higher level when */ /* needed. */ metrics->vertBearingX = 0; metrics->vertBearingY = 0; metrics->vertAdvance = 0; } break; case 6: case 7: case 9: /* variable big metrics */ if ( FT_STREAM_READ_FIELDS( sbit_metrics_fields, metrics ) ) goto Exit; break; case 5: default: /* constant metrics */ if ( range->index_format == 2 || range->index_format == 5 ) *metrics = range->metrics; else return SFNT_Err_Invalid_File_Format; } Exit: return error; } /*************************************************************************/ /* */ /* <Function> */ /* crop_bitmap */ /* */ /* <Description> */ /* Crops a bitmap to its tightest bounding box, and adjusts its */ /* metrics. */ /* */ /* <InOut> */ /* map :: The bitmap. */ /* */ /* metrics :: The corresponding metrics structure. */ /* */ static void crop_bitmap( FT_Bitmap* map, TT_SBit_Metrics metrics ) { /***********************************************************************/ /* */ /* In this situation, some bounding boxes of embedded bitmaps are too */ /* large. We need to crop it to a reasonable size. */ /* */ /* --------- */ /* | | ----- */ /* | *** | |***| */ /* | * | | * | */ /* | * | ------> | * | */ /* | * | | * | */ /* | * | | * | */ /* | *** | |***| */ /* --------- ----- */ /* */ /***********************************************************************/ FT_Int rows, count; FT_Long line_len; FT_Byte* line; /***********************************************************************/ /* */ /* first of all, check the top-most lines of the bitmap, and remove */ /* them if they're empty. */ /* */ { line = (FT_Byte*)map->buffer; rows = map->rows; line_len = map->pitch; for ( count = 0; count < rows; count++ ) { FT_Byte* cur = line; FT_Byte* limit = line + line_len; for ( ; cur < limit; cur++ ) if ( cur[0] ) goto Found_Top; /* the current line was empty - skip to next one */ line = limit; } Found_Top: /* check that we have at least one filled line */ if ( count >= rows ) goto Empty_Bitmap; /* now, crop the empty upper lines */ if ( count > 0 ) { line = (FT_Byte*)map->buffer; FT_MEM_MOVE( line, line + count * line_len, ( rows - count ) * line_len ); metrics->height = (FT_Byte)( metrics->height - count ); metrics->horiBearingY = (FT_Char)( metrics->horiBearingY - count ); metrics->vertBearingY = (FT_Char)( metrics->vertBearingY - count ); map->rows -= count; rows -= count; } } /***********************************************************************/ /* */ /* second, crop the lower lines */ /* */ { line = (FT_Byte*)map->buffer + ( rows - 1 ) * line_len; for ( count = 0; count < rows; count++ ) { FT_Byte* cur = line; FT_Byte* limit = line + line_len; for ( ; cur < limit; cur++ ) if ( cur[0] ) goto Found_Bottom; /* the current line was empty - skip to previous one */ line -= line_len; } Found_Bottom: if ( count > 0 ) { metrics->height = (FT_Byte)( metrics->height - count ); rows -= count; map->rows -= count; } } /***********************************************************************/ /* */ /* third, get rid of the space on the left side of the glyph */ /* */ do { FT_Byte* limit; line = (FT_Byte*)map->buffer; limit = line + rows * line_len; for ( ; line < limit; line += line_len ) if ( line[0] & 0x80 ) goto Found_Left; /* shift the whole glyph one pixel to the left */ line = (FT_Byte*)map->buffer; limit = line + rows * line_len; for ( ; line < limit; line += line_len ) { FT_Int n, width = map->width; FT_Byte old; FT_Byte* cur = line; old = (FT_Byte)(cur[0] << 1); for ( n = 8; n < width; n += 8 ) { FT_Byte val; val = cur[1]; cur[0] = (FT_Byte)( old | ( val >> 7 ) ); old = (FT_Byte)( val << 1 ); cur++; } cur[0] = old; } map->width--; metrics->horiBearingX++; metrics->vertBearingX++; metrics->width--; } while ( map->width > 0 ); Found_Left: /***********************************************************************/ /* */ /* finally, crop the bitmap width to get rid of the space on the right */ /* side of the glyph. */ /* */ do { FT_Int right = map->width - 1; FT_Byte* limit; FT_Byte mask; line = (FT_Byte*)map->buffer + ( right >> 3 ); limit = line + rows * line_len; mask = (FT_Byte)( 0x80 >> ( right & 7 ) ); for ( ; line < limit; line += line_len ) if ( line[0] & mask ) goto Found_Right; /* crop the whole glyph to the right */ map->width--; metrics->width--; } while ( map->width > 0 ); Found_Right: /* all right, the bitmap was cropped */ return; Empty_Bitmap: map->width = 0; map->rows = 0; map->pitch = 0; map->pixel_mode = FT_PIXEL_MODE_MONO; } static FT_Error Load_SBit_Single( FT_Bitmap* map, FT_Int x_offset, FT_Int y_offset, FT_Int pix_bits, FT_UShort image_format, TT_SBit_Metrics metrics, FT_Stream stream ) { FT_Error error; /* check that the source bitmap fits into the target pixmap */ if ( x_offset < 0 || x_offset + metrics->width > map->width || y_offset < 0 || y_offset + metrics->height > map->rows ) { error = SFNT_Err_Invalid_Argument; goto Exit; } { FT_Int glyph_width = metrics->width; FT_Int glyph_height = metrics->height; FT_Int glyph_size; FT_Int line_bits = pix_bits * glyph_width; FT_Bool pad_bytes = 0; /* compute size of glyph image */ switch ( image_format ) { case 1: /* byte-padded formats */ case 6: { FT_Int line_length; switch ( pix_bits ) { case 1: line_length = ( glyph_width + 7 ) >> 3; break; case 2: line_length = ( glyph_width + 3 ) >> 2; break; case 4: line_length = ( glyph_width + 1 ) >> 1; break; default: line_length = glyph_width; } glyph_size = glyph_height * line_length; pad_bytes = 1; } break; case 2: case 5: case 7: line_bits = glyph_width * pix_bits; glyph_size = ( glyph_height * line_bits + 7 ) >> 3; break; default: /* invalid format */ return SFNT_Err_Invalid_File_Format; } /* Now read data and draw glyph into target pixmap */ if ( FT_FRAME_ENTER( glyph_size ) ) goto Exit; /* don't forget to multiply `x_offset' by `map->pix_bits' as */ /* the sbit blitter doesn't make a difference between pixmap */ /* depths. */ blit_sbit( map, (FT_Byte*)stream->cursor, line_bits, pad_bytes, x_offset * pix_bits, y_offset, metrics->height ); FT_FRAME_EXIT(); } Exit: return error; } static FT_Error Load_SBit_Image( TT_SBit_Strike strike, TT_SBit_Range range, FT_ULong ebdt_pos, FT_ULong glyph_offset, FT_GlyphSlot slot, FT_Int x_offset, FT_Int y_offset, FT_Stream stream, TT_SBit_Metrics metrics, FT_Int depth ) { FT_Memory memory = stream->memory; FT_Bitmap* map = &slot->bitmap; FT_Error error; /* place stream at beginning of glyph data and read metrics */ if ( FT_STREAM_SEEK( ebdt_pos + glyph_offset ) ) goto Exit; error = tt_load_sbit_metrics( stream, range, metrics ); if ( error ) goto Exit; /* This function is recursive. At the top-level call, we */ /* compute the dimensions of the higher-level glyph to */ /* allocate the final pixmap buffer. */ if ( depth == 0 ) { FT_Long size; map->width = metrics->width; map->rows = metrics->height; switch ( strike->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: return SFNT_Err_Invalid_File_Format; } size = map->rows * map->pitch; /* check that there is no empty image */ if ( size == 0 ) goto Exit; /* exit successfully! */ error = ft_glyphslot_alloc_bitmap( slot, size ); if (error) goto Exit; } switch ( range->image_format ) { case 1: /* single sbit image - load it */ case 2: case 5: case 6: case 7: return Load_SBit_Single( map, x_offset, y_offset, strike->bit_depth, range->image_format, metrics, stream ); case 8: /* compound format */ if ( FT_STREAM_SKIP( 1L ) ) { error = SFNT_Err_Invalid_Stream_Skip; goto Exit; } /* fallthrough */ case 9: break; default: /* invalid image format */ return SFNT_Err_Invalid_File_Format; } /* All right, we have a compound format. First of all, read */ /* the array of elements. */ { TT_SBit_Component components; TT_SBit_Component comp; FT_UShort num_components, count; if ( FT_READ_USHORT( num_components ) || FT_NEW_ARRAY( components, num_components ) ) goto Exit; count = num_components; if ( FT_FRAME_ENTER( 4L * num_components ) ) goto Fail_Memory; for ( comp = components; count > 0; count--, comp++ ) { comp->glyph_code = FT_GET_USHORT(); comp->x_offset = FT_GET_CHAR(); comp->y_offset = FT_GET_CHAR(); } FT_FRAME_EXIT(); /* Now recursively load each element glyph */ count = num_components; comp = components; for ( ; count > 0; count--, comp++ ) { TT_SBit_Range elem_range; TT_SBit_MetricsRec elem_metrics; FT_ULong elem_offset; /* find the range for this element */ error = find_sbit_range( comp->glyph_code, strike, &elem_range, &elem_offset ); if ( error ) goto Fail_Memory; /* now load the element, recursively */ error = Load_SBit_Image( strike, elem_range, ebdt_pos, elem_offset, slot, x_offset + comp->x_offset, y_offset + comp->y_offset, stream, &elem_metrics, depth + 1 ); if ( error ) goto Fail_Memory; } Fail_Memory: FT_FREE( components ); } Exit: return error; } /*************************************************************************/ /* */ /* <Function> */ /* tt_face_load_sbit_image */ /* */ /* <Description> */ /* Loads a given glyph sbit image from the font resource. This also */ /* returns its metrics. */ /* */ /* <Input> */ /* face :: The target face object. */ /* */ /* strike_index :: The current strike index. */ /* */ /* glyph_index :: The current glyph index. */ /* */ /* load_flags :: The glyph load flags (the code checks for the flag */ /* FT_LOAD_CROP_BITMAP). */ /* */ /* stream :: The input stream. */ /* */ /* <Output> */ /* map :: The target pixmap. */ /* */ /* metrics :: A big sbit metrics structure for the glyph image. */ /* */ /* <Return> */ /* FreeType error code. 0 means success. Returns an error if no */ /* glyph sbit exists for the index. */ /* */ /* <Note> */ /* The `map.buffer' field is always freed before the glyph is loaded. */ /* */ FT_LOCAL_DEF( 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 ) { FT_Error error; FT_ULong ebdt_pos, glyph_offset; TT_SBit_Strike strike; TT_SBit_Range range; /* Check whether there is a glyph sbit for the current index */ error = tt_find_sbit_image( face, glyph_index, strike_index, &range, &strike, &glyph_offset ); if ( error ) goto Exit; /* now, find the location of the `EBDT' table in */ /* the font file */ error = face->goto_table( face, TTAG_EBDT, stream, 0 ); if ( error ) error = face->goto_table( face, TTAG_bdat, stream, 0 ); if ( error ) goto Exit; ebdt_pos = FT_STREAM_POS(); error = Load_SBit_Image( strike, range, ebdt_pos, glyph_offset, face->root.glyph, 0, 0, stream, metrics, 0 ); if ( error ) goto Exit; /* setup vertical metrics if needed */ if ( strike->flags & 1 ) { /* in case of a horizontal strike only */ FT_Int advance; advance = strike->hori.ascender - strike->hori.descender; /* some heuristic values */ metrics->vertBearingX = (FT_Char)(-metrics->width / 2 ); metrics->vertBearingY = (FT_Char)( ( advance - metrics->height ) / 2 ); metrics->vertAdvance = (FT_Char)( advance * 12 / 10 ); } /* Crop the bitmap now, unless specified otherwise */ if ( load_flags & FT_LOAD_CROP_BITMAP ) crop_bitmap( map, metrics ); Exit: return error; } #endif /* FT_CONFIG_OPTION_OLD_INTERNALS */ /* END */