/***************************************************************************/ /* */ /* ftccmap.c */ /* */ /* FreeType CharMap cache (body) */ /* */ /* Copyright 2000-2001, 2002, 2003 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 #include FT_FREETYPE_H #include FT_CACHE_H #include FT_CACHE_INTERNAL_MANAGER_H #include FT_INTERNAL_MEMORY_H #include FT_INTERNAL_DEBUG_H #include FT_TRUETYPE_IDS_H #include "ftcerror.h" #undef FT_COMPONENT #define FT_COMPONENT trace_cache /*************************************************************************/ /* */ /* 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 corresponding glyph 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 /* compute a query/node hash */ #define FTC_CMAP_HASH( faceid, index, charcode ) \ ( FTC_FACE_ID_HASH( faceid ) + 211*( index ) + ((char_code) / FTC_CMAP_INDICES_MAX) ) /* the charmap query */ typedef struct FTC_CMapQueryRec_ { FTC_FaceID face_id; FT_UInt cmap_index; FT_UInt32 char_code; } FTC_CMapQueryRec, *FTC_CMapQuery; #define FTC_CMAP_QUERY(x) ((FTC_CMapQuery)(x)) #define FTC_CMAP_QUERY_HASH(x) FTC_CMAP_HASH( (x)->face_id, (x)->cmap_index, (x)->char_code ) /* the cmap cache node */ typedef struct FTC_CMapNodeRec_ { FTC_NodeRec node; FTC_FaceID face_id; FT_UInt cmap_index; 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 ) ) #define FTC_CMAP_NODE_HASH(x) FTC_CMAP_HASH( (x)->face_id, (x)->cmap_index, (x)->first ) /* 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 ) /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** CHARMAP NODES *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ /* no need for specific finalizer; we use "ftc_node_done" directly */ FT_CALLBACK_DEF( void ) ftc_cmap_node_free( FTC_CMapNode node, FTC_Cache cache ) { FT_Memory memory = cache->memory; FT_FREE( node ); } /* initialize a new cmap node */ FT_CALLBACK_DEF( FT_Error ) ftc_cmap_node_new( FTC_CMapNode *anode, FTC_CMapQuery query, FTC_Cache cache ) { FT_Error error; FT_Memory memory = cache->memory; FTC_CMapNode node; FT_UInt nn; if ( !FT_NEW( node ) ) { node->face_id = query->face_id; node->cmap_index = query->cmap_index; node->first = (query->char_code / FTC_CMAP_INDICES_MAX) * FTC_CMAP_INDICES_MAX; for ( nn = 0; nn < FTC_CMAP_INDICES_MAX; nn++ ) node->indices[nn] = FTC_CMAP_UNKNOWN; } *anode = node; return error; } /* 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 node, FTC_CMapQuery query ) { if ( node->face_id == query->face_id && node->cmap_index == query->cmap_index ) { FT_UInt32 offset = (FT_UInt32)( query->char_code - node->first ); return FT_BOOL( offset < FTC_CMAP_INDICES_MAX ); } return 0; } FT_CALLBACK_DEF( FT_Bool ) ftc_cmap_node_remove_faceid( FTC_CMapNode node, FTC_FaceID face_id ) { return FT_BOOL( node->face_id == face_id ); } /*************************************************************************/ /*************************************************************************/ /***** *****/ /***** GLYPH IMAGE CACHE *****/ /***** *****/ /*************************************************************************/ /*************************************************************************/ FT_CALLBACK_TABLE_DEF const FTC_CacheClassRec ftc_cmap_cache_class = { (FTC_Node_NewFunc) ftc_cmap_node_new, (FTC_Node_WeightFunc) ftc_cmap_node_weight, (FTC_Node_CompareFunc) ftc_cmap_node_compare, (FTC_Node_CompareFunc) ftc_cmap_node_remove_faceid, (FTC_Node_FreeFunc) ftc_cmap_node_free, sizeof ( FTC_CacheRec ), (FTC_Cache_InitFunc) FTC_Cache_Init, (FTC_Cache_DoneFunc) FTC_Cache_Done, }; /* documentation is in ftccmap.h */ FT_EXPORT_DEF( FT_Error ) FTC_CMapCache_New( FTC_Manager manager, FTC_CMapCache *acache ) { return FTC_Manager_RegisterCache( manager, & ftc_cmap_cache_class, FTC_CACHE_P( acache ) ); } /* documentation is in ftccmap.h */ FT_EXPORT_DEF( FT_UInt ) FTC_CMapCache_Lookup( FTC_CMapCache cmap_cache, FTC_FaceID face_id, FT_Int cmap_index, FT_UInt32 char_code ) { FTC_Cache cache = FTC_CACHE( cmap_cache ); FTC_CMapQueryRec query; FTC_CMapNode node; FT_Error error; FT_UInt gindex = 0; FT_UInt32 hash; if ( !cache ) { FT_ERROR(( "FTC_CMapCache_Lookup: bad arguments, returning 0!\n" )); return 0; } query.face_id = face_id; query.cmap_index = (FT_UInt)cmap_index; query.char_code = char_code; hash = FTC_CMAP_HASH( face_id, cmap_index, char_code ); #if 1 FTC_CACHE_LOOKUP_CMP( cache, ftc_cmap_node_compare, hash, &query, node, error ); #else error = FTC_Cache_Lookup( cache, hash, &query, (FTC_Node*) &node ); #endif if ( error ) goto Exit; FT_ASSERT( (FT_UInt)( char_code - node->first ) < FTC_CMAP_INDICES_MAX ); gindex = node->indices[ char_code - node->first ]; if ( gindex == FTC_CMAP_UNKNOWN ) { FT_Face face; gindex = 0; error = FTC_Manager_LookupFace( cache->manager, node->face_id, &face ); if ( error ) goto Exit; if ( (FT_UInt)cmap_index < (FT_UInt)face->num_charmaps ) { FT_CharMap old, cmap = NULL; old = face->charmap; cmap = face->charmaps[ cmap_index ]; if (old != cmap) FT_Set_Charmap( face, cmap ); gindex = FT_Get_Char_Index( face, char_code ); if (old != cmap) FT_Set_Charmap( face, old ); } node->indices[ char_code - node->first ] = gindex; } Exit: return gindex; } /* END */