Edit
kc3-lang/freetype/src/sfnt/ttmtx.c
Werner Lemberg
- src/sfnt/ttmtx.c
-
/**************************************************************************** * * ttmtx.c * * Load the metrics tables common to TTF and OTF fonts (body). * * Copyright (C) 2006-2020 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 <freetype/internal/ftdebug.h> #include <freetype/internal/ftstream.h> #include <freetype/tttags.h> #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT #include <freetype/internal/services/svmetric.h> #endif #include "ttmtx.h" #include "sferrors.h" /* IMPORTANT: The TT_HoriHeader and TT_VertHeader structures should */ /* be identical except for the names of their fields, */ /* which are different. */ /* */ /* This ensures that `tt_face_load_hmtx' is able to read */ /* both the horizontal and vertical headers. */ /************************************************************************** * * 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 ttmtx /************************************************************************** * * @Function: * tt_face_load_hmtx * * @Description: * Load the `hmtx' or `vmtx' table into a face object. * * @Input: * face :: * A handle to the target face object. * * stream :: * The input stream. * * vertical :: * A boolean flag. If set, load `vmtx'. * * @Return: * FreeType error code. 0 means success. */ FT_LOCAL_DEF( FT_Error ) tt_face_load_hmtx( TT_Face face, FT_Stream stream, FT_Bool vertical ) { FT_Error error; FT_ULong tag, table_size; FT_ULong* ptable_offset; FT_ULong* ptable_size; if ( vertical ) { tag = TTAG_vmtx; ptable_offset = &face->vert_metrics_offset; ptable_size = &face->vert_metrics_size; } else { tag = TTAG_hmtx; ptable_offset = &face->horz_metrics_offset; ptable_size = &face->horz_metrics_size; } error = face->goto_table( face, tag, stream, &table_size ); if ( error ) goto Fail; *ptable_size = table_size; *ptable_offset = FT_STREAM_POS(); Fail: return error; } /************************************************************************** * * @Function: * tt_face_load_hhea * * @Description: * Load the `hhea' or 'vhea' table into a face object. * * @Input: * face :: * A handle to the target face object. * * stream :: * The input stream. * * vertical :: * A boolean flag. If set, load `vhea'. * * @Return: * FreeType error code. 0 means success. */ FT_LOCAL_DEF( FT_Error ) tt_face_load_hhea( TT_Face face, FT_Stream stream, FT_Bool vertical ) { FT_Error error; TT_HoriHeader* header; static const FT_Frame_Field metrics_header_fields[] = { #undef FT_STRUCTURE #define FT_STRUCTURE TT_HoriHeader FT_FRAME_START( 36 ), FT_FRAME_ULONG ( Version ), FT_FRAME_SHORT ( Ascender ), FT_FRAME_SHORT ( Descender ), FT_FRAME_SHORT ( Line_Gap ), FT_FRAME_USHORT( advance_Width_Max ), FT_FRAME_SHORT ( min_Left_Side_Bearing ), FT_FRAME_SHORT ( min_Right_Side_Bearing ), FT_FRAME_SHORT ( xMax_Extent ), FT_FRAME_SHORT ( caret_Slope_Rise ), FT_FRAME_SHORT ( caret_Slope_Run ), FT_FRAME_SHORT ( caret_Offset ), FT_FRAME_SHORT ( Reserved[0] ), FT_FRAME_SHORT ( Reserved[1] ), FT_FRAME_SHORT ( Reserved[2] ), FT_FRAME_SHORT ( Reserved[3] ), FT_FRAME_SHORT ( metric_Data_Format ), FT_FRAME_USHORT( number_Of_HMetrics ), FT_FRAME_END }; if ( vertical ) { void *v = &face->vertical; error = face->goto_table( face, TTAG_vhea, stream, 0 ); if ( error ) goto Fail; header = (TT_HoriHeader*)v; } else { error = face->goto_table( face, TTAG_hhea, stream, 0 ); if ( error ) goto Fail; header = &face->horizontal; } if ( FT_STREAM_READ_FIELDS( metrics_header_fields, header ) ) goto Fail; FT_TRACE3(( "Ascender: %5d\n", header->Ascender )); FT_TRACE3(( "Descender: %5d\n", header->Descender )); FT_TRACE3(( "number_Of_Metrics: %5u\n", header->number_Of_HMetrics )); header->long_metrics = NULL; header->short_metrics = NULL; Fail: return error; } /************************************************************************** * * @Function: * tt_face_get_metrics * * @Description: * Return the horizontal or vertical metrics in font units for a * given glyph. The values are the left side bearing (top side * bearing for vertical metrics) and advance width (advance height * for vertical metrics). * * @Input: * face :: * A pointer to the TrueType face structure. * * vertical :: * If set to TRUE, get vertical metrics. * * gindex :: * The glyph index. * * @Output: * abearing :: * The bearing, either left side or top side. * * aadvance :: * The advance width or advance height, depending on * the `vertical' flag. */ FT_LOCAL_DEF( void ) tt_face_get_metrics( TT_Face face, FT_Bool vertical, FT_UInt gindex, FT_Short *abearing, FT_UShort *aadvance ) { FT_Error error; FT_Stream stream = face->root.stream; TT_HoriHeader* header; FT_ULong table_pos, table_size, table_end; FT_UShort k; #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT FT_Service_MetricsVariations var = (FT_Service_MetricsVariations)face->var; #endif if ( vertical ) { void* v = &face->vertical; header = (TT_HoriHeader*)v; table_pos = face->vert_metrics_offset; table_size = face->vert_metrics_size; } else { header = &face->horizontal; table_pos = face->horz_metrics_offset; table_size = face->horz_metrics_size; } table_end = table_pos + table_size; k = header->number_Of_HMetrics; if ( k > 0 ) { if ( gindex < (FT_UInt)k ) { table_pos += 4 * gindex; if ( table_pos + 4 > table_end ) goto NoData; if ( FT_STREAM_SEEK( table_pos ) || FT_READ_USHORT( *aadvance ) || FT_READ_SHORT( *abearing ) ) goto NoData; } else { table_pos += 4 * ( k - 1 ); if ( table_pos + 2 > table_end ) goto NoData; if ( FT_STREAM_SEEK( table_pos ) || FT_READ_USHORT( *aadvance ) ) goto NoData; table_pos += 4 + 2 * ( gindex - k ); if ( table_pos + 2 > table_end ) *abearing = 0; else { if ( FT_STREAM_SEEK( table_pos ) ) *abearing = 0; else (void)FT_READ_SHORT( *abearing ); } } } else { NoData: *abearing = 0; *aadvance = 0; } #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT if ( var ) { FT_Face f = FT_FACE( face ); FT_Int a = (FT_Int)*aadvance; FT_Int b = (FT_Int)*abearing; if ( vertical ) { if ( var->vadvance_adjust ) var->vadvance_adjust( f, gindex, &a ); if ( var->tsb_adjust ) var->tsb_adjust( f, gindex, &b ); } else { if ( var->hadvance_adjust ) var->hadvance_adjust( f, gindex, &a ); if ( var->lsb_adjust ) var->lsb_adjust( f, gindex, &b ); } *aadvance = (FT_UShort)a; *abearing = (FT_Short)b; } #endif } /* END */