--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/libfreetype/src/sfnt/ttsbit0.c Mon Apr 25 01:46:54 2011 +0200
@@ -0,0 +1,1011 @@
+/***************************************************************************/
+/* */
+/* 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 */