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+/***************************************************************************/
+/* */
+/* ftcglyph.h */
+/* */
+/* FreeType abstract glyph cache (specification). */
+/* */
+/* Copyright 2000-2001, 2003, 2004, 2006, 2007 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. */
+/* */
+/***************************************************************************/
+
+
+ /*
+ *
+ * FTC_GCache is an _abstract_ cache object optimized to store glyph
+ * data. It works as follows:
+ *
+ * - It manages FTC_GNode objects. Each one of them can hold one or more
+ * glyph `items'. Item types are not specified in the FTC_GCache but
+ * in classes that extend it.
+ *
+ * - Glyph attributes, like face ID, character size, render mode, etc.,
+ * can be grouped into abstract `glyph families'. This avoids storing
+ * the attributes within the FTC_GCache, since it is likely that many
+ * FTC_GNodes will belong to the same family in typical uses.
+ *
+ * - Each FTC_GNode is thus an FTC_Node with two additional fields:
+ *
+ * * gindex: A glyph index, or the first index in a glyph range.
+ * * family: A pointer to a glyph `family'.
+ *
+ * - Family types are not fully specific in the FTC_Family type, but
+ * by classes that extend it.
+ *
+ * Note that both FTC_ImageCache and FTC_SBitCache extend FTC_GCache.
+ * They share an FTC_Family sub-class called FTC_BasicFamily which is
+ * used to store the following data: face ID, pixel/point sizes, load
+ * flags. For more details see the file `src/cache/ftcbasic.c'.
+ *
+ * Client applications can extend FTC_GNode with their own FTC_GNode
+ * and FTC_Family sub-classes to implement more complex caches (e.g.,
+ * handling automatic synthesis, like obliquing & emboldening, colored
+ * glyphs, etc.).
+ *
+ * See also the FTC_ICache & FTC_SCache classes in `ftcimage.h' and
+ * `ftcsbits.h', which both extend FTC_GCache with additional
+ * optimizations.
+ *
+ * A typical FTC_GCache implementation must provide at least the
+ * following:
+ *
+ * - FTC_GNode sub-class, e.g. MyNode, with relevant methods:
+ * my_node_new (must call FTC_GNode_Init)
+ * my_node_free (must call FTC_GNode_Done)
+ * my_node_compare (must call FTC_GNode_Compare)
+ * my_node_remove_faceid (must call ftc_gnode_unselect in case
+ * of match)
+ *
+ * - FTC_Family sub-class, e.g. MyFamily, with relevant methods:
+ * my_family_compare
+ * my_family_init
+ * my_family_reset (optional)
+ * my_family_done
+ *
+ * - FTC_GQuery sub-class, e.g. MyQuery, to hold cache-specific query
+ * data.
+ *
+ * - Constant structures for a FTC_GNodeClass.
+ *
+ * - MyCacheNew() can be implemented easily as a call to the convenience
+ * function FTC_GCache_New.
+ *
+ * - MyCacheLookup with a call to FTC_GCache_Lookup. This function will
+ * automatically:
+ *
+ * - Search for the corresponding family in the cache, or create
+ * a new one if necessary. Put it in FTC_GQUERY(myquery).family
+ *
+ * - Call FTC_Cache_Lookup.
+ *
+ * If it returns NULL, you should create a new node, then call
+ * ftc_cache_add as usual.
+ */
+
+
+ /*************************************************************************/
+ /* */
+ /* Important: The functions defined in this file are only used to */
+ /* implement an abstract glyph cache class. You need to */
+ /* provide additional logic to implement a complete cache. */
+ /* */
+ /*************************************************************************/
+
+
+ /*************************************************************************/
+ /*************************************************************************/
+ /*************************************************************************/
+ /*************************************************************************/
+ /*************************************************************************/
+ /********* *********/
+ /********* WARNING, THIS IS BETA CODE. *********/
+ /********* *********/
+ /*************************************************************************/
+ /*************************************************************************/
+ /*************************************************************************/
+ /*************************************************************************/
+ /*************************************************************************/
+
+
+#ifndef __FTCGLYPH_H__
+#define __FTCGLYPH_H__
+
+
+#include <ft2build.h>
+#include "ftcmanag.h"
+
+
+FT_BEGIN_HEADER
+
+
+ /*
+ * We can group glyphs into `families'. Each family correspond to a
+ * given face ID, character size, transform, etc.
+ *
+ * Families are implemented as MRU list nodes. They are
+ * reference-counted.
+ */
+
+ typedef struct FTC_FamilyRec_
+ {
+ FTC_MruNodeRec mrunode;
+ FT_UInt num_nodes; /* current number of nodes in this family */
+ FTC_Cache cache;
+ FTC_MruListClass clazz;
+
+ } FTC_FamilyRec, *FTC_Family;
+
+#define FTC_FAMILY(x) ( (FTC_Family)(x) )
+#define FTC_FAMILY_P(x) ( (FTC_Family*)(x) )
+
+
+ typedef struct FTC_GNodeRec_
+ {
+ FTC_NodeRec node;
+ FTC_Family family;
+ FT_UInt gindex;
+
+ } FTC_GNodeRec, *FTC_GNode;
+
+#define FTC_GNODE( x ) ( (FTC_GNode)(x) )
+#define FTC_GNODE_P( x ) ( (FTC_GNode*)(x) )
+
+
+ typedef struct FTC_GQueryRec_
+ {
+ FT_UInt gindex;
+ FTC_Family family;
+
+ } FTC_GQueryRec, *FTC_GQuery;
+
+#define FTC_GQUERY( x ) ( (FTC_GQuery)(x) )
+
+
+ /*************************************************************************/
+ /* */
+ /* These functions are exported so that they can be called from */
+ /* user-provided cache classes; otherwise, they are really part of the */
+ /* cache sub-system internals. */
+ /* */
+
+ /* must be called by derived FTC_Node_InitFunc routines */
+ FT_LOCAL( void )
+ FTC_GNode_Init( FTC_GNode node,
+ FT_UInt gindex, /* glyph index for node */
+ FTC_Family family );
+
+ /* returns TRUE iff the query's glyph index correspond to the node; */
+ /* this assumes that the `family' and `hash' fields of the query are */
+ /* already correctly set */
+ FT_LOCAL( FT_Bool )
+ FTC_GNode_Compare( FTC_GNode gnode,
+ FTC_GQuery gquery );
+
+ /* call this function to clear a node's family -- this is necessary */
+ /* to implement the `node_remove_faceid' cache method correctly */
+ FT_LOCAL( void )
+ FTC_GNode_UnselectFamily( FTC_GNode gnode,
+ FTC_Cache cache );
+
+ /* must be called by derived FTC_Node_DoneFunc routines */
+ FT_LOCAL( void )
+ FTC_GNode_Done( FTC_GNode node,
+ FTC_Cache cache );
+
+
+ FT_LOCAL( void )
+ FTC_Family_Init( FTC_Family family,
+ FTC_Cache cache );
+
+ typedef struct FTC_GCacheRec_
+ {
+ FTC_CacheRec cache;
+ FTC_MruListRec families;
+
+ } FTC_GCacheRec, *FTC_GCache;
+
+#define FTC_GCACHE( x ) ((FTC_GCache)(x))
+
+
+#if 0
+ /* can be used as @FTC_Cache_InitFunc */
+ FT_LOCAL( FT_Error )
+ FTC_GCache_Init( FTC_GCache cache );
+#endif
+
+
+#if 0
+ /* can be used as @FTC_Cache_DoneFunc */
+ FT_LOCAL( void )
+ FTC_GCache_Done( FTC_GCache cache );
+#endif
+
+
+ /* the glyph cache class adds fields for the family implementation */
+ typedef struct FTC_GCacheClassRec_
+ {
+ FTC_CacheClassRec clazz;
+ FTC_MruListClass family_class;
+
+ } FTC_GCacheClassRec;
+
+ typedef const FTC_GCacheClassRec* FTC_GCacheClass;
+
+#define FTC_GCACHE_CLASS( x ) ((FTC_GCacheClass)(x))
+
+#define FTC_CACHE__GCACHE_CLASS( x ) \
+ FTC_GCACHE_CLASS( FTC_CACHE(x)->org_class )
+#define FTC_CACHE__FAMILY_CLASS( x ) \
+ ( (FTC_MruListClass)FTC_CACHE__GCACHE_CLASS( x )->family_class )
+
+
+ /* convenience function; use it instead of FTC_Manager_Register_Cache */
+ FT_LOCAL( FT_Error )
+ FTC_GCache_New( FTC_Manager manager,
+ FTC_GCacheClass clazz,
+ FTC_GCache *acache );
+
+#ifndef FTC_INLINE
+ FT_LOCAL( FT_Error )
+ FTC_GCache_Lookup( FTC_GCache cache,
+ FT_UInt32 hash,
+ FT_UInt gindex,
+ FTC_GQuery query,
+ FTC_Node *anode );
+#endif
+
+
+ /* */
+
+
+#define FTC_FAMILY_FREE( family, cache ) \
+ FTC_MruList_Remove( &FTC_GCACHE((cache))->families, \
+ (FTC_MruNode)(family) )
+
+
+#ifdef FTC_INLINE
+
+#define FTC_GCACHE_LOOKUP_CMP( cache, famcmp, nodecmp, hash, \
+ gindex, query, node, error ) \
+ FT_BEGIN_STMNT \
+ FTC_GCache _gcache = FTC_GCACHE( cache ); \
+ FTC_GQuery _gquery = (FTC_GQuery)( query ); \
+ FTC_MruNode_CompareFunc _fcompare = (FTC_MruNode_CompareFunc)(famcmp); \
+ \
+ \
+ _gquery->gindex = (gindex); \
+ \
+ FTC_MRULIST_LOOKUP_CMP( &_gcache->families, _gquery, _fcompare, \
+ _gquery->family, error ); \
+ if ( !error ) \
+ { \
+ FTC_Family _gqfamily = _gquery->family; \
+ \
+ \
+ _gqfamily->num_nodes++; \
+ \
+ FTC_CACHE_LOOKUP_CMP( cache, nodecmp, hash, query, node, error ); \
+ \
+ if ( --_gqfamily->num_nodes == 0 ) \
+ FTC_FAMILY_FREE( _gqfamily, _gcache ); \
+ } \
+ FT_END_STMNT
+ /* */
+
+#else /* !FTC_INLINE */
+
+#define FTC_GCACHE_LOOKUP_CMP( cache, famcmp, nodecmp, hash, \
+ gindex, query, node, error ) \
+ FT_BEGIN_STMNT \
+ void* _n = &(node); \
+ \
+ \
+ error = FTC_GCache_Lookup( FTC_GCACHE( cache ), hash, gindex, \
+ FTC_GQUERY( query ), (FTC_Node*)_n ); \
+ FT_END_STMNT
+
+#endif /* !FTC_INLINE */
+
+
+FT_END_HEADER
+
+
+#endif /* __FTCGLYPH_H__ */
+
+
+/* END */