File indexing completed on 2024-04-28 11:38:26

0001 /*
0002     Large image displaying library.
0003 
0004     Copyright (C) 2004,2005 Maks Orlovich (maksim@kde.org)
0005 
0006     Permission is hereby granted, free of charge, to any person obtaining a copy
0007     of this software and associated documentation files (the "Software"), to deal
0008     in the Software without restriction, including without limitation the rights
0009     to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
0010     copies of the Software, and to permit persons to whom the Software is
0011     furnished to do so, subject to the following conditions:
0012 
0013     The above copyright notice and this permission notice shall be included in
0014     all copies or substantial portions of the Software.
0015 
0016     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
0017     IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
0018     FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
0019     AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
0020     AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
0021     CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
0022 
0023 */
0024 
0025 #ifndef TILE_H
0026 #define TILE_H
0027 
0028 #include <cstring>
0029 
0030 
0031 namespace khtmlImLoad
0032 {
0033 
0034 class TileCache;
0035 class TileCacheNode;
0036 
0037 /**
0038  We hold pointers tiles in the cache. The interface is simple: when they get
0039  kicked out of the cache, the discard method is invoked to have the associated
0040  resources freed. Note that the cache does not own the entries, but merely
0041  mages the more expensive part of their resources. The cacheEntry
0042  field is used to link the tile node to the appropriate cache entry for it.
0043 */
0044 class Tile
0045 {
0046 public:
0047     enum {TileSize = 64};
0048     //Note:this can be safely reduced, but not increased --- ScaledPlane
0049     //relies for byte offsets in a single row in a tile fitting into bytes
0050 
0051     unsigned char versions[Tile::TileSize];
0052 protected:
0053     friend class TileCache;
0054 
0055     Tile(): cacheNode(nullptr)
0056     {
0057         std::memset(versions, 0, Tile::TileSize);
0058     }
0059     virtual ~Tile() {}
0060     virtual void discard() = 0;
0061 
0062     TileCacheNode *cacheNode;
0063 };
0064 
0065 }
0066 
0067 #endif