shithub: freetype+ttf2subf

ref: 4b92cf80c7d99fb86454ea989ccf9ff9d379180c
dir: /src/cache/ftcglyph.c/

View raw version
/***************************************************************************/
/*                                                                         */
/*  ftcglyph.c                                                             */
/*                                                                         */
/*    FreeType Glyph Image (FT_Glyph) cache..                              */
/*                                                                         */
/*  Copyright 2000 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.                                        */
/*                                                                         */
/*                                                                         */
/*  Note: the implementation of glyph queues is rather generic in this     */
/*        code. This will allow other glyph node/cache types to be         */
/*        easily included in the future.. For now, we only cache           */
/*        glyph images..                                                   */
/*                                                                         */
/***************************************************************************/


#include <freetype/cache/ftcglyph.h>
#include <freetype/fterrors.h>
#include <freetype/internal/ftobjs.h>
#include <freetype/internal/ftlist.h>
#include <freetype/fterrors.h>

 /*************************************************************************/
 /*************************************************************************/
 /*****                                                               *****/
 /*****                      GLYPH NODES                              *****/
 /*****                                                               *****/
 /*************************************************************************/
 /*************************************************************************/
 
/* in the future, we might provide a better scheme for managing       */
/* glyph node element. For the moment, we simply use FT_Alloc/FT_Free */

 /* creates a new glyph node, setting its cache index and ref count */
  FT_EXPORT_FUNC(void)   FTC_GlyphNode_Init( FTC_GlyphNode    node,
                                             FTC_Glyph_Queue  queue,
                                             FT_UInt          gindex )
  {
    FTC_Glyph_Cache      cache = queue->cache;
    FTC_CacheNode_Data*  data  = FTC_CACHENODE_TO_DATA_P( &node->root );
      
    data->cache_index = (FT_UShort) cache->root.cache_index;
    data->ref_count   = (FT_Short)  0;
    node->queue_index = (FT_UShort) queue->queue_index;
    node->glyph_index = (FT_UShort) gindex;
  }




  /* Important: this function is called from the cache manager to */
  /* destroy a given cache node during "cache compression". The   */
  /* second argument is always "cache.user_data". You thus be     */
  /* certain that the function FTC_Image_Cache_New does indeed    */
  /* set its "user_data" field correctly, otherwise bad things    */
  /* will happen !!                                               */
  
  FT_EXPORT_FUNC(void)  FTC_GlyphNode_Destroy( FTC_GlyphNode    node,
                                               FTC_Glyph_Cache  cache )
  {
    FT_LruNode       queue_lru = cache->queues_lru->nodes+node->queue_index;
    FTC_Glyph_Queue  queue     = (FTC_Glyph_Queue)queue_lru->root.data;
    FT_UInt          hash      = node->glyph_index % queue->hash_size;
    FT_List          bucket    = queue->buckets + hash;
    
    /* remove node from its queue's bucket list */
    FT_List_Remove( bucket, FTC_GLYPHNODE_TO_LISTNODE(node) );
    
    /* destroy the node */
    queue->clazz->destroy_node( node, queue );
  }

  
  /* Important: this function is called from the cache manager to */
  /* size a given cache node during "cache compression". The      */
  /* second argument is always "cache.user_data". You thus be     */
  /* certain that the function FTC_Image_Cache_New does indeed    */
  /* set its "user_data" field correctly, otherwise bad things    */
  /* will happen !!                                               */
  
  FT_EXPORT_FUNC(FT_ULong)  FTC_GlyphNode_Size( FTC_GlyphNode    node,
                                                FTC_Glyph_Cache  cache )
  {
    FT_LruNode       queue_lru = cache->queues_lru->nodes+node->queue_index;
    FTC_Glyph_Queue  queue     = (FTC_Glyph_Queue)queue_lru->root.data;
    
    return queue->clazz->size_node( node, queue );
  }


  FT_CPLUSPLUS(const FTC_CacheNode_Class)   ftc_glyph_cache_node_class =
  {
    (FTC_CacheNode_SizeFunc)     FTC_GlyphNode_Size,
    (FTC_CacheNode_DestroyFunc)  FTC_GlyphNode_Destroy
  };

 /*************************************************************************/
 /*************************************************************************/
 /*****                                                               *****/
 /*****                      GLYPH QUEUES                             *****/
 /*****                                                               *****/
 /*************************************************************************/
 /*************************************************************************/

 FT_EXPORT_FUNC(FT_Error)  FTC_Glyph_Queue_New(
                                 FTC_Glyph_Cache   cache,
                                 FT_Pointer        type,
                                 FTC_Glyph_Queue*  aqueue )
  {
    FT_Error         error;
    FT_Memory        memory  = cache->root.memory;
    FTC_Manager      manager = cache->root.manager;
    FTC_Glyph_Queue  queue   = 0;
    
    FTC_Glyph_Cache_Class* gcache_class;
    FTC_Glyph_Queue_Class* clazz;
    
    gcache_class = (FTC_Glyph_Cache_Class*)cache->root.clazz;
    clazz        = gcache_class->queue_class;
    
    *aqueue = 0;
    
    if ( ALLOC( queue, clazz->queue_byte_size ) )
      goto Exit;
    
    queue->cache     = cache;
    queue->manager   = manager;
    queue->memory    = memory;
    queue->hash_size = FTC_QUEUE_HASH_SIZE_DEFAULT;
    queue->clazz     = clazz;

    /* allocate buckets table */
    if ( ALLOC_ARRAY( queue->buckets, queue->hash_size, FT_ListRec ) )
    if (error)
      goto Exit;

    /* initialize queue by type - if needed */
    if (clazz->init)
    {
      error = clazz->init( queue, type );
      if (error)
        goto Exit;
    }

    *aqueue = queue;

  Exit:
    if ( error && queue )
    {
      FREE( queue->buckets );
      FREE( queue );
    }

    return error;
  }                                  



  FT_EXPORT_FUNC(void)  FTC_Glyph_Queue_Done( FTC_Glyph_Queue  queue )
  {
    FTC_Glyph_Cache  cache        = queue->cache;
    FTC_Manager      manager      = cache->root.manager;
    FT_List          glyphs_lru   = &manager->global_lru;
    FT_List          bucket       = queue->buckets;
    FT_List          bucket_limit = bucket + queue->hash_size;
    FT_Memory        memory       = cache->root.memory;
    
    FTC_Glyph_Queue_Class*  clazz = queue->clazz;

    /* for each bucket, free the list of Glyph nodes */
    for ( ; bucket < bucket_limit; bucket++ )
    {
      FT_ListNode    node = bucket->head;
      FT_ListNode    next = 0;
      FT_ListNode    lrunode;
      FTC_GlyphNode  inode;
      

      for ( ; node; node = next )
      {
        next    = node->next;
        inode   = FTC_LISTNODE_TO_GLYPHNODE(node);
        lrunode = FTC_GLYPHNODE_TO_LRUNODE( inode );
        
        manager->num_bytes -= clazz->size_node( inode, queue );
        
        FT_List_Remove( glyphs_lru, lrunode );

        clazz->destroy_node( inode, queue );
      }
      
      bucket->head = bucket->tail = 0;
    }

    if (clazz->done)
      clazz->done(queue);

    FREE( queue->buckets );
    FREE( queue );
  }


  FT_EXPORT_FUNC(FT_Error)  FTC_Glyph_Queue_Lookup_Node(
                                         FTC_Glyph_Queue  queue,
                                         FT_UInt          glyph_index,
                                         FTC_GlyphNode*   anode )
  {
    FTC_Glyph_Cache       cache      = queue->cache;
    FTC_Manager           manager    = cache->root.manager;
    FT_UInt               hash_index = glyph_index % queue->hash_size;
    FT_List               bucket     = queue->buckets + hash_index;
    FT_ListNode           node;
    FT_Error              error;
    FTC_GlyphNode         inode;
    
    FTC_Glyph_Queue_Class*  clazz = queue->clazz;

    *anode = 0;
    for ( node = bucket->head; node; node = node->next )
    {
      FT_UInt  gindex;
      
      inode  = FTC_LISTNODE_TO_GLYPHNODE(node);
      gindex = inode->glyph_index;
      
      if ( gindex == glyph_index )
      {
        /* we found it! -- move glyph to start of the lists */
        FT_List_Up( bucket, node );
        FT_List_Up( &manager->global_lru, FTC_GLYPHNODE_TO_LRUNODE( inode ) );
        *anode = inode;
        return 0;
      }
    }

    /* we didn't found the glyph image, we will now create a new one */
    error = clazz->new_node( queue, glyph_index, &inode );
    if ( error )
      goto Exit;

    /* insert the node at the start of our bucket list */
    FT_List_Insert( bucket, FTC_GLYPHNODE_TO_LISTNODE(inode) );
    
    /* insert the node at the start the global LRU glyph list */
    FT_List_Insert( &manager->global_lru, FTC_GLYPHNODE_TO_LRUNODE(inode) );
    
    manager->num_bytes += clazz->size_node( inode, queue );

    if (manager->num_bytes > manager->max_bytes)
      FTC_Manager_Compress( manager );
      
    *anode = inode;

  Exit:
    return error;
  }

  
  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                   GLYPH QUEUES LRU CALLBACKS                  *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/
 

#define FTC_QUEUE_LRU_GET_CACHE( lru )   \
          ( (FTC_Glyph_Cache)(lru)->user_data )
          
#define FTC_QUEUE_LRU_GET_MANAGER( lru ) \
          FTC_QUEUE_LRU_GET_CACHE( lru )->manager
          
#define FTC_LRUNODE_QUEUE( node )        \
          ( (FTC_Glyph_Queue)(node)->root.data )


  LOCAL_FUNC_X
  FT_Error  ftc_glyph_queue_lru_init( FT_Lru      lru,
                                      FT_LruNode  node )
  {
    FTC_Glyph_Cache  cache = FTC_QUEUE_LRU_GET_CACHE( lru );
    FT_Error         error;
    FTC_Glyph_Queue  queue;

    error = FTC_Glyph_Queue_New( cache,
                                 (FT_Pointer)node->key,
                                 &queue );
    if ( !error )
    {
      /* good, now set the queue index within the queue object */
      queue->queue_index = node - lru->nodes;
      node->root.data    = queue;
    }
    
    return error;
  }



  LOCAL_FUNC_X
  void  ftc_glyph_queue_lru_done( FT_Lru      lru,
                                  FT_LruNode  node )
  {
    FTC_Glyph_Queue  queue = FTC_LRUNODE_QUEUE( node );
    
    FT_UNUSED( lru );


    FTC_Glyph_Queue_Done( queue );
  }



  LOCAL_FUNC_X
  FT_Bool  ftc_glyph_queue_lru_compare( FT_LruNode  node,
                                        FT_LruKey   key )
  {
    FTC_Glyph_Queue  queue = FTC_LRUNODE_QUEUE( node );
    return queue->clazz->compare( queue, (FT_Pointer)key );
  }                                            



  FT_CPLUSPLUS( const FT_Lru_Class )  ftc_glyph_queue_lru_class =
  {
    sizeof( FT_LruRec ),
    ftc_glyph_queue_lru_init,
    ftc_glyph_queue_lru_done,
    0,  /* no flush */
    ftc_glyph_queue_lru_compare
  };



  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                GLYPH IMAGE CACHE OBJECTS                      *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/
 

  FT_EXPORT_FUNC(FT_Error)   FTC_Glyph_Cache_Init( FTC_Glyph_Cache cache )
  {
    FT_Memory               memory = cache->root.memory;
    FT_Error                error;

    /* set up root node_class to be used by manager */
    cache->root.node_clazz = (FTC_CacheNode_Class*)&ftc_glyph_cache_node_class;
    
    /* The following is extremely important for ftc_destroy_glyph_image */
    /* to work properly, as the second parameter that is sent to it     */
    /* through the cache manager is "user_data" and must be set to      */
    /* "cache" here..                                                   */
    /*                                                                  */
    cache->root.cache_user = cache;

    error = FT_Lru_New( &ftc_glyph_queue_lru_class,
                        FTC_MAX_GLYPH_QUEUES,
                        cache,
                        memory,
                        1, /* pre_alloc == TRUE */
                        &cache->queues_lru );
    return error;
  }


  FT_EXPORT_FUNC(void)    FTC_Glyph_Cache_Done( FTC_Glyph_Cache  cache )
  {
    /* discard Glyph queues */
    FT_Lru_Done( cache->queues_lru );
  }



/* END */