ref: 53478a10b482a1aca2272bb0ab7a128ed1a8f201
dir: /src/cache/ftccmap.c/
/***************************************************************************/
/* */
/* ftccmap.c */
/* */
/* FreeType CharMap cache (body) */
/* */
/* Copyright 2000-2001, 2002, 2003, 2004, 2005, 2006 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 "ftcmanag.h"
#include FT_INTERNAL_MEMORY_H
#include FT_INTERNAL_DEBUG_H
#include FT_TRUETYPE_IDS_H
#include "ftccback.h"
#include "ftcerror.h"
#undef FT_COMPONENT
#define FT_COMPONENT trace_cache
#ifdef FT_CONFIG_OPTION_OLD_INTERNALS
typedef enum FTC_OldCMapType_
{
FTC_OLD_CMAP_BY_INDEX = 0,
FTC_OLD_CMAP_BY_ENCODING = 1,
FTC_OLD_CMAP_BY_ID = 2
} FTC_OldCMapType;
typedef struct FTC_OldCMapIdRec_
{
FT_UInt platform;
FT_UInt encoding;
} FTC_OldCMapIdRec, *FTC_OldCMapId;
typedef struct FTC_OldCMapDescRec_
{
FTC_FaceID face_id;
FTC_OldCMapType type;
union
{
FT_UInt index;
FT_Encoding encoding;
FTC_OldCMapIdRec id;
} u;
} FTC_OldCMapDescRec, *FTC_OldCMapDesc;
#endif /* FT_CONFIG_OLD_INTERNALS */
/*************************************************************************/
/* */
/* 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 *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
FT_CALLBACK_DEF( void )
ftc_cmap_node_free( FTC_Node ftcnode,
FTC_Cache cache )
{
FTC_CMapNode node = (FTC_CMapNode)ftcnode;
FT_Memory memory = cache->memory;
FT_FREE( node );
}
/* initialize a new cmap node */
FT_CALLBACK_DEF( FT_Error )
ftc_cmap_node_new( FTC_Node *ftcanode,
FT_Pointer ftcquery,
FTC_Cache cache )
{
FTC_CMapNode *anode = (FTC_CMapNode*)ftcanode;
FTC_CMapQuery query = (FTC_CMapQuery)ftcquery;
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_Node cnode,
FTC_Cache cache )
{
FT_UNUSED( cnode );
FT_UNUSED( cache );
return sizeof ( *cnode );
}
/* compare a cmap node to a given query */
FT_CALLBACK_DEF( FT_Bool )
ftc_cmap_node_compare( FTC_Node ftcnode,
FT_Pointer ftcquery,
FTC_Cache cache )
{
FTC_CMapNode node = (FTC_CMapNode)ftcnode;
FTC_CMapQuery query = (FTC_CMapQuery)ftcquery;
FT_UNUSED( cache );
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_Node ftcnode,
FT_Pointer ftcface_id,
FTC_Cache cache )
{
FTC_CMapNode node = (FTC_CMapNode)ftcnode;
FTC_FaceID face_id = (FTC_FaceID)ftcface_id;
FT_UNUSED( cache );
return FT_BOOL( node->face_id == face_id );
}
/*************************************************************************/
/*************************************************************************/
/***** *****/
/***** GLYPH IMAGE CACHE *****/
/***** *****/
/*************************************************************************/
/*************************************************************************/
FT_CALLBACK_TABLE_DEF
const FTC_CacheClassRec ftc_cmap_cache_class =
{
ftc_cmap_node_new,
ftc_cmap_node_weight,
ftc_cmap_node_compare,
ftc_cmap_node_remove_faceid,
ftc_cmap_node_free,
sizeof ( FTC_CacheRec ),
ftc_cache_init,
ftc_cache_done,
};
/* documentation is in ftcache.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 ) );
}
#ifdef FT_CONFIG_OPTION_OLD_INTERNALS
/*
* Unfortunately, it is not possible to support binary backwards
* compatibility in the cmap cache. The FTC_CMapCache_Lookup signature
* changes were too deep, and there is no clever hackish way to detect
* what kind of structure we are being passed.
*
* On the other hand it seems that no production code is using this
* function on Unix distributions.
*/
#endif
/* documentation is in ftcache.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;
}
#ifdef FT_CONFIG_OPTION_OLD_INTERNALS
/*
* Detect a call from a rogue client that thinks it is linking
* to FreeType 2.1.7. This is possible because the third parameter
* is then a character code, and we have never seen any font with
* more than a few charmaps, so if the index is very large...
*
* It is also very unlikely that a rogue client is interested
* in Unicode values 0 to 3.
*/
if ( cmap_index >= 4 )
{
FTC_OldCMapDesc desc = (FTC_OldCMapDesc) face_id;
char_code = (FT_UInt32)cmap_index;
query.face_id = desc->face_id;
switch ( desc->type )
{
case FTC_OLD_CMAP_BY_INDEX:
query.cmap_index = desc->u.index;
query.char_code = (FT_UInt32)cmap_index;
break;
case FTC_OLD_CMAP_BY_ENCODING:
{
FT_Face face;
error = FTC_Manager_LookupFace( cache->manager, desc->face_id,
&face );
if ( error )
return 0;
FT_Select_Charmap( face, desc->u.encoding );
return FT_Get_Char_Index( face, char_code );
}
break;
default:
return 0;
}
}
else
#endif /* FT_CONFIG_OPTION_OLD_INTERNALS */
{
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 );
/* something rotten can happen with rogue clients */
if ( (FT_UInt)( char_code - node->first >= FTC_CMAP_INDICES_MAX ) )
return 0;
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] = (FT_UShort)gindex;
}
Exit:
return gindex;
}
/* END */