ref: ce9a0441ad2f0508649251373ceedb1b01f97b22
dir: /src/cache/ftccmap.c/
/***************************************************************************/ /* */ /* ftccmap.c */ /* */ /* FreeType CharMap cache (body) */ /* */ /* Copyright 2000-2001 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_FREETYPE_H #include FT_CACHE_H #include FT_CACHE_CHARMAP_H #include FT_CACHE_MANAGER_H #include FT_INTERNAL_MEMORY_H #include FT_INTERNAL_DEBUG_H #include "ftcerror.h" /*************************************************************************/ /* */ /* Each FTC_CMapNode contains a simple array to map a range of character */ /* codes to equivalent glyph indices. */ /* */ /* For now, the implementation is very basic: Each node maps a range of */ /* 128 consecutive character codes to their correspondingglyph indices. */ /* */ /* We could do more complex things, but I don't think it is really very */ /* useful. */ /* */ /*************************************************************************/ /* number of glyph indices / character code per node */ #define FTC_CMAP_INDICES_MAX 128 typedef struct FTC_CMapNodeRec_ { FTC_NodeRec node; FT_UInt32 first; /* first character in node */ FT_UInt16 indices[FTC_CMAP_INDICES_MAX]; /* array of glyph indices */ } FTC_CMapNodeRec, *FTC_CMapNode; #define FTC_CMAP_NODE( x ) ( (FTC_CMapNode)( x ) ) /* compute node hash value from cmap family and "requested" glyph index */ #define FTC_CMAP_HASH( cfam, cquery ) \ ( (cfam)->hash + ( (cquery)->char_code / FTC_CMAP_INDICES_MAX ) ) /* if (indices[n] == FTC_CMAP_UNKNOWN), we assume that the corresponding */ /* glyph indices haven't been queried through FT_Get_Glyph_Index() yet */ #define FTC_CMAP_UNKNOWN ( (FT_UInt16)-1 ) /* the charmap query */ typedef struct FTC_CMapQueryRec_ { FTC_QueryRec query; FTC_CMapDesc desc; FT_UInt32 char_code; } FTC_CMapQueryRec, *FTC_CMapQuery; #define FTC_CMAP_QUERY( x ) ( (FTC_CMapQuery)( x ) ) /* the charmap family */ typedef struct FTC_CMapFamilyRec_ { FTC_FamilyRec family; FT_UInt32 hash; FTC_CMapDescRec desc; FT_UInt index; } FTC_CMapFamilyRec, *FTC_CMapFamily; #define FTC_CMAP_FAMILY( x ) ( (FTC_CMapFamily)( x ) ) #define FTC_CMAP_FAMILY_MEMORY( x ) FTC_FAMILY( x )->memory /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** CHARMAP NODES *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ /* no need for specific finalizer; we use "ftc_node_done" directly */ /* initialize a new cmap node */ FT_CALLBACK_DEF( FT_Error ) ftc_cmap_node_init( FTC_CMapNode cnode, FTC_CMapQuery cquery, FTC_Cache cache ) { FT_UInt32 first; FT_UInt n; FT_UNUSED( cache ); first = ( cquery->char_code / FTC_CMAP_INDICES_MAX ) * FTC_CMAP_INDICES_MAX; cnode->first = first; for ( n = 0; n < FTC_CMAP_INDICES_MAX; n++ ) cnode->indices[n] = FTC_CMAP_UNKNOWN; return 0; } /* compute the weight of a given cmap node */ FT_CALLBACK_DEF( FT_ULong ) ftc_cmap_node_weight( FTC_CMapNode cnode ) { FT_UNUSED(cnode); return sizeof ( *cnode ); } /* compare a cmap node to a given query */ FT_CALLBACK_DEF( FT_Bool ) ftc_cmap_node_compare( FTC_CMapNode cnode, FTC_CMapQuery cquery ) { FT_UInt32 offset = (FT_UInt32)( cquery->char_code - cnode->first ); return FT_BOOL( offset < FTC_CMAP_INDICES_MAX ); } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** CHARMAP FAMILY *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ FT_CALLBACK_DEF( FT_Error ) ftc_cmap_family_init( FTC_CMapFamily cfam, FTC_CMapQuery cquery, FTC_Cache cache ) { FTC_Manager manager = cache->manager; FTC_CMapDesc desc = cquery->desc; FT_UInt32 hash = 0; FT_Error error; FT_Face face; /* setup charmap descriptor */ cfam->desc = *desc; /* let's see whether the rest is correct too */ error = FTC_Manager_Lookup_Face( manager, desc->face_id, &face ); if ( !error ) { FT_UInt count = face->num_charmaps; FT_UInt index = count; FT_CharMap* cur = face->charmaps; switch ( desc->type ) { case FTC_CMAP_BY_INDEX: index = desc->u.index; hash = index * 33; break; case FTC_CMAP_BY_ENCODING: for ( index = 0; index < count; index++, cur++ ) if ( cur[0]->encoding == desc->u.encoding ) break; hash = index * 67; break; case FTC_CMAP_BY_ID: for ( index = 0; index < count; index++, cur++ ) { if ( (FT_UInt)cur[0]->platform_id == desc->u.id.platform && (FT_UInt)cur[0]->encoding_id == desc->u.id.encoding ) { hash = ( ( desc->u.id.platform << 8 ) | desc->u.id.encoding ) * 7; break; } } break; default: ; } if ( index >= count ) goto Bad_Descriptor; /* compute hash value, both in family and query */ cfam->index = index; cfam->hash = hash ^ FTC_FACE_ID_HASH( desc->face_id ); FTC_QUERY( cquery )->hash = FTC_CMAP_HASH( cfam, cquery ); error = ftc_family_init( FTC_FAMILY( cfam ), FTC_QUERY( cquery ), cache ); } return error; Bad_Descriptor: FT_ERROR(( "ftp_cmap_family_init: invalid charmap descriptor\n" )); return FT_Err_Invalid_Argument; } FT_CALLBACK_DEF( FT_Bool ) ftc_cmap_family_compare( FTC_CMapFamily cfam, FTC_CMapQuery cquery ) { FT_Int result = 0; /* first, compare face id and type */ if ( cfam->desc.face_id != cquery->desc->face_id || cfam->desc.type != cquery->desc->type ) goto Exit; switch ( cfam->desc.type ) { case FTC_CMAP_BY_INDEX: result = ( cfam->desc.u.index == cquery->desc->u.index ); break; case FTC_CMAP_BY_ENCODING: result = ( cfam->desc.u.encoding == cquery->desc->u.encoding ); break; case FTC_CMAP_BY_ID: result = ( cfam->desc.u.id.platform == cquery->desc->u.id.platform && cfam->desc.u.id.encoding == cquery->desc->u.id.encoding ); break; default: ; } if ( result ) { /* when found, update the 'family' and 'hash' field of the query */ FTC_QUERY( cquery )->family = FTC_FAMILY( cfam ); FTC_QUERY( cquery )->hash = FTC_CMAP_HASH( cfam, cquery ); } Exit: return FT_BOOL( result ); } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** GLYPH IMAGE CACHE *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ FT_CALLBACK_TABLE_DEF const FTC_Cache_ClassRec ftc_cmap_cache_class = { sizeof ( FTC_CacheRec ), (FTC_Cache_InitFunc) ftc_cache_init, (FTC_Cache_ClearFunc)ftc_cache_clear, (FTC_Cache_DoneFunc) ftc_cache_done, sizeof ( FTC_CMapFamilyRec ), (FTC_Family_InitFunc) ftc_cmap_family_init, (FTC_Family_CompareFunc)ftc_cmap_family_compare, (FTC_Family_DoneFunc) ftc_family_done, sizeof ( FTC_CMapNodeRec ), (FTC_Node_InitFunc) ftc_cmap_node_init, (FTC_Node_WeightFunc) ftc_cmap_node_weight, (FTC_Node_CompareFunc)ftc_cmap_node_compare, (FTC_Node_DoneFunc) ftc_node_done }; /* documentation is in ftccmap.h */ FT_EXPORT_DEF( FT_Error ) FTC_CMapCache_New( FTC_Manager manager, FTC_CMapCache *acache ) { return FTC_Manager_Register_Cache( manager, (FTC_Cache_Class)&ftc_cmap_cache_class, FTC_CACHE_P( acache ) ); } /* documentation is in ftccmap.h */ FT_EXPORT_DEF( FT_UInt ) FTC_CMapCache_Lookup( FTC_CMapCache cache, FTC_CMapDesc desc, FT_UInt32 char_code ) { FTC_CMapQueryRec cquery; FTC_CMapNode node; FT_Error error; FT_UInt gindex = 0; if ( !cache || !desc ) { FT_ERROR(( "FTC_CMapCache_Lookup: bad arguments, returning 0!\n" )); return 0; } cquery.desc = desc; cquery.char_code = char_code; error = ftc_cache_lookup( FTC_CACHE( cache ), FTC_QUERY( &cquery ), (FTC_Node*)&node ); if ( !error ) { FT_UInt offset = (FT_UInt)( char_code - node->first ); gindex = node->indices[offset]; if ( gindex == FTC_CMAP_UNKNOWN ) { FT_Face face; /* we need to use FT_Get_Char_Index */ gindex = 0; error = FTC_Manager_Lookup_Face( FTC_CACHE(cache)->manager, desc->face_id, &face ); if ( !error ) { FT_CharMap old, cmap = NULL; FT_UInt cmap_index; /* save old charmap, select new one */ old = face->charmap; cmap_index = FTC_CMAP_FAMILY( FTC_QUERY( &cquery )->family )->index; cmap = face->charmaps[cmap_index]; FT_Set_Charmap( face, cmap ); /* perform lookup */ gindex = FT_Get_Char_Index( face, char_code ); node->indices[offset] = (FT_UInt16) gindex; /* restore old charmap */ FT_Set_Charmap( face, old ); } } } return gindex; } /* END */