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Diffstat (limited to 'src/ChunkStay.h')
-rw-r--r-- | src/ChunkStay.h | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/src/ChunkStay.h b/src/ChunkStay.h new file mode 100644 index 000000000..2510cb490 --- /dev/null +++ b/src/ChunkStay.h @@ -0,0 +1,97 @@ + +// ChunkStay.h + +/* Declares the cChunkStay class representing a base for classes that want to wait for certain chunks to load, +then do some action on them. While the object is enabled, the chunks contained within are locked and will +not unload +*/ + + + + + +#pragma once + + + + + +// fwd +class cChunkMap; + + + + + +/** Makes chunks stay loaded until this object is cleared or destroyed +Works by setting internal flags in the cChunk that it should not be unloaded. +To optimize for speed, cChunkStay has an Enabled flag, it will "stay" the chunks only when enabled +and it will refuse chunk-list manipulations when enabled. +The object itself is not made thread-safe, it's supposed to be used from a single thread only. +This class is abstract, the descendants are expected to provide the OnChunkAvailable() and +the OnAllChunksAvailable() callback implementations. Note that those are called from the contexts of +different threads' - the caller, the Loader or the Generator thread. +*/ +class cChunkStay +{ +public: + cChunkStay(void); + virtual ~cChunkStay(); + + void Clear(void); + + /** Adds a chunk to be locked from unloading. + To be used only while the ChunkStay object is not enabled. */ + void Add(int a_ChunkX, int a_ChunkZ); + + /** Releases the chunk so that it's no longer locked from unloading. + To be used only while the ChunkStay object is not enabled. */ + void Remove(int a_ChunkX, int a_ChunkZ); + + /** Enables the ChunkStay on the specified chunkmap, causing it to load and generate chunks. + All the contained chunks are queued for loading / generating. */ + void Enable (cChunkMap & a_ChunkMap); + + /** Disables the ChunkStay, the chunks are released and the ChunkStay + object can be edited with Add() and Remove() again*/ + virtual void Disable(void); + + /** Returns all the chunks that should be kept */ + const cChunkCoordsVector & GetChunks(void) const { return m_Chunks; } + + /** Called when a specific chunk become available. */ + virtual void OnChunkAvailable(int a_ChunkX, int a_ChunkZ) = 0; + + /** Caled once all of the contained chunks are available. + If returns true, the ChunkStay is automatically disabled by the ChunkMap; if it returns false, the ChunkStay is kept. */ + virtual bool OnAllChunksAvailable(void) = 0; + + /** Called by the ChunkMap when the ChunkStay is disabled. The object may choose to delete itself. */ + virtual void OnDisabled(void) = 0; + +protected: + + friend class cChunkMap; + + + /** The chunkmap where the object is enabled. + Valid only after call to Enable() and before Disable(). */ + cChunkMap * m_ChunkMap; + + /** The list of chunks to lock from unloading. */ + cChunkCoordsVector m_Chunks; + + /** The chunks that still need loading */ + cChunkCoordsVector m_OutstandingChunks; + + + /** Called by cChunkMap when a chunk is available, checks m_NumLoaded and triggers the appropriate callbacks. + May be called for chunks outside this ChunkStay. + Returns true if the ChunkStay is to be automatically disabled by the ChunkMap; returns false to keep the ChunkStay. */ + bool ChunkAvailable(int a_ChunkX, int a_ChunkZ); +} ; + + + + + |