From a4a418a679f1ac760a8763edd856f0178cfc6dde Mon Sep 17 00:00:00 2001 From: "madmaxoft@gmail.com" Date: Fri, 25 May 2012 07:18:52 +0000 Subject: Merged the composable_generator branch into the trunk git-svn-id: http://mc-server.googlecode.com/svn/trunk@504 0a769ca7-a7f5-676a-18bf-c427514a06d6 --- source/LightingThread.h | 170 +++++++++++++++++++++++++++++++++++++----------- 1 file changed, 132 insertions(+), 38 deletions(-) (limited to 'source/LightingThread.h') diff --git a/source/LightingThread.h b/source/LightingThread.h index 5b60d34bf..0f8b59441 100644 --- a/source/LightingThread.h +++ b/source/LightingThread.h @@ -2,22 +2,48 @@ // LightingThread.h // Interfaces to the cLightingThread class representing the thread that processes requests for lighting -// Note that the world generators need direct access to the lighting methods so that they can light the generated chunk +/* +Lighting is done on whole chunks. For each chunk to be lighted, the whole 3x3 chunk area around it is read, +then it is processed, so that the middle chunk area has valid lighting, and the lighting is copied into the ChunkMap. +Lighting is calculated in full char arrays instead of nibbles, so that accessing the arrays is fast. +Lighting is calculated in a flood-fill fashion: +1. Generate seeds from where the light spreads (full skylight / light-emitting blocks) +2. For each seed: + - Spread the light 1 block in each of the 6 cardinal directions, if the blocktype allows + - If the recipient block has had lower lighting value than that being spread, make it a new seed +3. Repeat step 2, until there are no more seeds +The seeds need two fast operations: + - Check if a block at [x, y, z] is already a seed + - Get the next seed in the row +For that reason it is stored in two arrays, one stores a bool saying a seed is in that position, +the other is an array of seed coords, encoded as a single int. +Step 2 needs two separate storages for old seeds and new seeds, so there are two actual storages for that purpose, +their content is swapped after each full step-2-cycle. + +The thread has two queues of chunks that are to be lighted. +The first queue, m_Queue, is the only one that is publicly visible, chunks get queued there by external requests. +The second one, m_PostponedQueue, is for chunks that have been taken out of m_Queue and didn't have neighbors ready. +Chunks from m_PostponedQueue are moved back into m_Queue when their neighbors get valid, using the ChunkReady callback. +*/ #pragma once #include "cIsThread.h" +#include "ChunkDef.h" -// fwd: +// fwd: "cWorld.h" class cWorld; +// fwd: "cChunkMap.h" +class cChunkStay; + @@ -28,53 +54,121 @@ class cLightingThread : typedef cIsThread super; public: - - class cLightingBuffer - { - public: - cLightingBuffer(int m_MinX, int m_MaxX, int m_MinY, int m_MaxY, int m_MinZ, int m_MaxZ); - - /// Copies the world's existing chunks into m_BlockData, m_Skylight and m_BlockLight - void GetFromWorld(cWorld * a_World); - void SetToWorld (cWorld * a_World); - - void Process(void); // Does the actual lighting on this buffer - - protected: - - // Block coords: - int m_MinX, m_MaxX; - int m_MinY, m_MaxY; - int m_MinZ, m_MaxZ; - - int m_StrideX; // = OffsetOfBlock(x, y, z) - OffsetOfBlock(x + 1, y, z) - int m_StrideZ; // = OffsetOfBlock(x, y, z) - OffsetOfBlock(x, y, z + 1) - - // These buffers actually store 1 block in each direction more than is specified in the coords - // This way we can throw out a lot of conditions inside the processing cycles - // And it allows us to light a chunk with regard to its surrounding chunks without much work - // (So if m_MinX is 16 and m_MaxX is 32, the buffers actually contain data for X in range from 15 to 33 (18 items) - char * m_BlockData; - char * m_SkyLight; - char * m_BlockLight; - } ; cLightingThread(void); ~cLightingThread(); + bool Start(cWorld * a_World); + void Stop(void); - void QueueLighting(cWorld * a_World, int a_MinX, int a_MaxX, int a_MinY, int a_MaxY, int a_MinZ, int a_MaxZ); // queues the request - + /// Queues the entire chunk for lighting + void QueueChunk(int a_ChunkX, int a_ChunkZ, cChunkCoordCallback * a_CallbackAfter = NULL); + + /// Blocks until the queue is empty or the thread is terminated + void WaitForQueueEmpty(void); + + size_t GetQueueLength(void); + + /// Called from cWorld when a chunk gets valid. Chunks in m_PostponedQueue may need moving into m_Queue + void ChunkReady(int a_ChunkX, int a_ChunkZ); + protected: - typedef std::list cLightingBufferQueue; + struct sItem + { + int x, z; + cChunkStay * m_ChunkStay; + cChunkCoordCallback * m_Callback; + + sItem(void) {} // empty default constructor needed + sItem(int a_X, int a_Z, cChunkStay * a_ChunkStay, cChunkCoordCallback * a_Callback) : + x(a_X), + z(a_Z), + m_ChunkStay(a_ChunkStay), + m_Callback(a_Callback) + { + } + } ; + + typedef std::list sItems; - cCriticalSection m_CS; - cLightingBufferQueue m_Queue; - cEvent m_Event; // Set when queue is appended or to stop the thread + cWorld * m_World; + cCriticalSection m_CS; + sItems m_Queue; + sItems m_PostponedQueue; // Chunks that have been postponed due to missing neighbors + cEvent m_evtItemAdded; // Set when queue is appended, or to stop the thread + cEvent m_evtQueueEmpty; // Set when the queue gets empty + // Buffers for the 3x3 chunk data + // These buffers alone are 1.7 MiB in size, therefore they cannot be located on the stack safely - some architectures may have only 1 MiB for stack, or even less + // Placing the buffers into the object means that this object can light chunks only in one thread! + // The blobs are XZY organized as a whole, instead of 3x3 XZY-organized subarrays -> + // -> This means data has to be scatterred when reading and gathered when writing! + static const int BlocksPerYLayer = cChunkDef::Width * cChunkDef::Width * 3 * 3; + BLOCKTYPE m_BlockTypes[BlocksPerYLayer * cChunkDef::Height]; + NIBBLETYPE m_BlockLight[BlocksPerYLayer * cChunkDef::Height]; + NIBBLETYPE m_SkyLight [BlocksPerYLayer * cChunkDef::Height]; + HEIGHTTYPE m_HeightMap [BlocksPerYLayer]; + + // Seed management (5.7 MiB) + // Two buffers, in each calc step one is set as input and the other as output, then in the next step they're swapped + // Each seed is represented twice in this structure - both as a "list" and as a "position". + // "list" allows fast traversal from seed to seed + // "position" allows fast checking if a coord is already a seed + unsigned char m_IsSeed1 [BlocksPerYLayer * cChunkDef::Height]; + unsigned int m_SeedIdx1[BlocksPerYLayer * cChunkDef::Height]; + unsigned char m_IsSeed2 [BlocksPerYLayer * cChunkDef::Height]; + unsigned int m_SeedIdx2[BlocksPerYLayer * cChunkDef::Height]; + int m_NumSeeds; + virtual void Execute(void) override; + + /// Lights the entire chunk. If neighbor chunks don't exist, touches them and re-queues the chunk + void LightChunk(sItem & a_Item); + + /// Prepares m_BlockTypes and m_HeightMap data; returns false if any of the chunks fail. Zeroes out the light arrays + bool ReadChunks(int a_ChunkX, int a_ChunkZ); + + /// Uses m_HeightMap to initialize the m_SkyLight[] data; fills in seeds for the skylight + void PrepareSkyLight(void); + + /// Uses m_BlockTypes to initialize the m_BlockLight[] data; fills in seeds for the blocklight + void PrepareBlockLight(void); + + /// Calculates light in the light array specified, using stored seeds + void CalcLight(NIBBLETYPE * a_Light); + + /// Does one step in the light calculation - one seed propagation and seed recalculation + void CalcLightStep( + NIBBLETYPE * a_Light, + int a_NumSeedsIn, unsigned char * a_IsSeedIn, unsigned int * a_SeedIdxIn, + int & a_NumSeedsOut, unsigned char * a_IsSeedOut, unsigned int * a_SeedIdxOut + ); + + /// Compresses from 1-byte-per-block into 2-bytes-per-block: + void CompressLight(NIBBLETYPE * a_LightArray, NIBBLETYPE * a_ChunkLight); + + inline void PropagateLight( + NIBBLETYPE * a_Light, + int a_SrcIdx, int a_DstIdx, + int & a_NumSeedsOut, unsigned char * a_IsSeedOut, unsigned int * a_SeedIdxOut + ) + { + if (a_Light[a_SrcIdx] <= a_Light[a_DstIdx] + g_BlockSpreadLightFalloff[m_BlockTypes[a_DstIdx]]) + { + // The dest block already has enough light than we're offerring + return; + } + + a_Light[a_DstIdx] = a_Light[a_SrcIdx] - g_BlockSpreadLightFalloff[m_BlockTypes[a_DstIdx]]; + if (!a_IsSeedOut[a_DstIdx]) + { + a_IsSeedOut[a_DstIdx] = true; + a_SeedIdxOut[a_NumSeedsOut++] = a_DstIdx; + } + } + } ; -- cgit v1.2.3