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/***************************************************************************/
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/* FreeType abstract glyph cache (specification). */
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/* Copyright 2000-2001, 2003, 2004, 2006, 2007, 2011 by */
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/* David Turner, Robert Wilhelm, and Werner Lemberg. */
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/* This file is part of the FreeType project, and may only be used, */
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/* modified, and distributed under the terms of the FreeType project */
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/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
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/* this file you indicate that you have read the license and */
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/* understand and accept it fully. */
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/***************************************************************************/
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* FTC_GCache is an _abstract_ cache object optimized to store glyph
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* data. It works as follows:
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* - It manages FTC_GNode objects. Each one of them can hold one or more
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* glyph `items'. Item types are not specified in the FTC_GCache but
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* in classes that extend it.
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* - Glyph attributes, like face ID, character size, render mode, etc.,
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* can be grouped into abstract `glyph families'. This avoids storing
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* the attributes within the FTC_GCache, since it is likely that many
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* FTC_GNodes will belong to the same family in typical uses.
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* - Each FTC_GNode is thus an FTC_Node with two additional fields:
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* * gindex: A glyph index, or the first index in a glyph range.
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* * family: A pointer to a glyph `family'.
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* - Family types are not fully specific in the FTC_Family type, but
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* by classes that extend it.
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* Note that both FTC_ImageCache and FTC_SBitCache extend FTC_GCache.
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* They share an FTC_Family sub-class called FTC_BasicFamily which is
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* used to store the following data: face ID, pixel/point sizes, load
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* flags. For more details see the file `src/cache/ftcbasic.c'.
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* Client applications can extend FTC_GNode with their own FTC_GNode
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* and FTC_Family sub-classes to implement more complex caches (e.g.,
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* handling automatic synthesis, like obliquing & emboldening, colored
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* See also the FTC_ICache & FTC_SCache classes in `ftcimage.h' and
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* `ftcsbits.h', which both extend FTC_GCache with additional
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* A typical FTC_GCache implementation must provide at least the
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* - FTC_GNode sub-class, e.g. MyNode, with relevant methods:
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* my_node_new (must call FTC_GNode_Init)
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* my_node_free (must call FTC_GNode_Done)
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* my_node_compare (must call FTC_GNode_Compare)
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* my_node_remove_faceid (must call ftc_gnode_unselect in case
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* - FTC_Family sub-class, e.g. MyFamily, with relevant methods:
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* my_family_reset (optional)
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* - FTC_GQuery sub-class, e.g. MyQuery, to hold cache-specific query
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* - Constant structures for a FTC_GNodeClass.
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* - MyCacheNew() can be implemented easily as a call to the convenience
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* function FTC_GCache_New.
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* - MyCacheLookup with a call to FTC_GCache_Lookup. This function will
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* - Search for the corresponding family in the cache, or create
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* a new one if necessary. Put it in FTC_GQUERY(myquery).family
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* - Call FTC_Cache_Lookup.
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* If it returns NULL, you should create a new node, then call
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* ftc_cache_add as usual.
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/*************************************************************************/
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/* Important: The functions defined in this file are only used to */
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/* implement an abstract glyph cache class. You need to */
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/* provide additional logic to implement a complete cache. */
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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/********* *********/
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/********* WARNING, THIS IS BETA CODE. *********/
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/********* *********/
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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#ifndef __FTCGLYPH_H__
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#define __FTCGLYPH_H__
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#include <ft2build.h>
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#include "ftcmanag.h"
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* We can group glyphs into `families'. Each family correspond to a
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* given face ID, character size, transform, etc.
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* Families are implemented as MRU list nodes. They are
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typedef struct FTC_FamilyRec_
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FTC_MruNodeRec mrunode;
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FT_UInt num_nodes; /* current number of nodes in this family */
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FTC_MruListClass clazz;
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} FTC_FamilyRec, *FTC_Family;
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#define FTC_FAMILY(x) ( (FTC_Family)(x) )
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#define FTC_FAMILY_P(x) ( (FTC_Family*)(x) )
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typedef struct FTC_GNodeRec_
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} FTC_GNodeRec, *FTC_GNode;
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#define FTC_GNODE( x ) ( (FTC_GNode)(x) )
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#define FTC_GNODE_P( x ) ( (FTC_GNode*)(x) )
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typedef struct FTC_GQueryRec_
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} FTC_GQueryRec, *FTC_GQuery;
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#define FTC_GQUERY( x ) ( (FTC_GQuery)(x) )
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/*************************************************************************/
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/* These functions are exported so that they can be called from */
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/* user-provided cache classes; otherwise, they are really part of the */
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/* cache sub-system internals. */
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/* must be called by derived FTC_Node_InitFunc routines */
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FTC_GNode_Init( FTC_GNode node,
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FT_UInt gindex, /* glyph index for node */
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/* returns TRUE iff the query's glyph index correspond to the node; */
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/* this assumes that the `family' and `hash' fields of the query are */
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/* already correctly set */
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FTC_GNode_Compare( FTC_GNode gnode,
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FT_Bool* list_changed );
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/* call this function to clear a node's family -- this is necessary */
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/* to implement the `node_remove_faceid' cache method correctly */
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FTC_GNode_UnselectFamily( FTC_GNode gnode,
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/* must be called by derived FTC_Node_DoneFunc routines */
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FTC_GNode_Done( FTC_GNode node,
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FTC_Family_Init( FTC_Family family,
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typedef struct FTC_GCacheRec_
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FTC_MruListRec families;
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} FTC_GCacheRec, *FTC_GCache;
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#define FTC_GCACHE( x ) ((FTC_GCache)(x))
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/* can be used as @FTC_Cache_InitFunc */
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FTC_GCache_Init( FTC_GCache cache );
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/* can be used as @FTC_Cache_DoneFunc */
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FTC_GCache_Done( FTC_GCache cache );
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/* the glyph cache class adds fields for the family implementation */
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typedef struct FTC_GCacheClassRec_
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FTC_CacheClassRec clazz;
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FTC_MruListClass family_class;
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} FTC_GCacheClassRec;
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typedef const FTC_GCacheClassRec* FTC_GCacheClass;
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#define FTC_GCACHE_CLASS( x ) ((FTC_GCacheClass)(x))
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#define FTC_CACHE__GCACHE_CLASS( x ) \
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FTC_GCACHE_CLASS( FTC_CACHE(x)->org_class )
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#define FTC_CACHE__FAMILY_CLASS( x ) \
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( (FTC_MruListClass)FTC_CACHE__GCACHE_CLASS( x )->family_class )
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/* convenience function; use it instead of FTC_Manager_Register_Cache */
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FTC_GCache_New( FTC_Manager manager,
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FTC_GCacheClass clazz,
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FTC_GCache *acache );
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FTC_GCache_Lookup( FTC_GCache cache,
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#define FTC_FAMILY_FREE( family, cache ) \
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FTC_MruList_Remove( &FTC_GCACHE((cache))->families, \
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(FTC_MruNode)(family) )
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#define FTC_GCACHE_LOOKUP_CMP( cache, famcmp, nodecmp, hash, \
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gindex, query, node, error ) \
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FTC_GCache _gcache = FTC_GCACHE( cache ); \
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FTC_GQuery _gquery = (FTC_GQuery)( query ); \
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FTC_MruNode_CompareFunc _fcompare = (FTC_MruNode_CompareFunc)(famcmp); \
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FTC_MruNode _mrunode; \
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_gquery->gindex = (gindex); \
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FTC_MRULIST_LOOKUP_CMP( &_gcache->families, _gquery, _fcompare, \
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_gquery->family = FTC_FAMILY( _mrunode ); \
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FTC_Family _gqfamily = _gquery->family; \
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_gqfamily->num_nodes++; \
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FTC_CACHE_LOOKUP_CMP( cache, nodecmp, hash, query, node, error ); \
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if ( --_gqfamily->num_nodes == 0 ) \
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FTC_FAMILY_FREE( _gqfamily, _gcache ); \
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#else /* !FTC_INLINE */
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#define FTC_GCACHE_LOOKUP_CMP( cache, famcmp, nodecmp, hash, \
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gindex, query, node, error ) \
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error = FTC_GCache_Lookup( FTC_GCACHE( cache ), hash, gindex, \
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FTC_GQUERY( query ), &node ); \
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#endif /* !FTC_INLINE */
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#endif /* __FTCGLYPH_H__ */
added
removed
misc/libfreetype/src/cache/ftcglyph.h
