QtBiomeVisualiser: Added multithreading.

For some reason this makes the UI less responsive.

Tools/QtBiomeVisualiser/ChunkSource.h

@@ -1,4 +1,5 @@
 #pragma once
+#include <QString>
 #include "Chunk.h"
 
 
@@ -7,6 +8,8 @@
 
 // fwd:
 class cBiomeGen;
+typedef std::shared_ptr<cBiomeGen> cBiomeGenPtr;
+class cIniFile;
 
 
 
@@ -21,6 +24,9 @@ public:
 	/** Fills the a_DestChunk with the biomes for the specified coords.
 	It is expected to be thread-safe and re-entrant. Usually QThread::idealThreadCount() threads are used. */
 	virtual void getChunkBiomes(int a_ChunkX, int a_ChunkZ, ChunkPtr a_DestChunk) = 0;
+
+	/** Forces a fresh reload of the source. Useful mainly for the generator, whose underlying definition file may have been changed. */
+	virtual void reload() = 0;
 };
 
 
@@ -32,15 +38,36 @@ class BioGenSource :
 	public ChunkSource
 {
 public:
-	/** Constructs a new BioGenSource based on the biome generator given.
-	Takes ownership of a_BiomeGen */
-	BioGenSource(cBiomeGen * a_BiomeGen);
+	/** Constructs a new BioGenSource based on the biome generator that is defined in the specified world.ini file. */
+	BioGenSource(QString a_WorldIniPath);
 
+	// ChunkSource overrides:
 	virtual void getChunkBiomes(int a_ChunkX, int a_ChunkZ, ChunkPtr a_DestChunk) override;
+	virtual void reload(void) override;
 
 protected:
-	std::shared_ptr<cBiomeGen> m_BiomeGen;
+	/** Path to the world.ini file from which the m_WorldIni is regenerated on reload requests. */
+	QString m_WorldIniPath;
+
+	/** Parsed contents of the world.ini file from which the biome generators are initialized.
+	Locked by m_Mtx to avoid multithreaded access. */
+	std::unique_ptr<cIniFile> m_WorldIni;
+
+	/** List of cBiomeGen instances that are "free" - aren't doing any generating at this moment.
+	Locked by m_Mtx to avoid multithreaded access. */
+	std::vector<cBiomeGenPtr> m_AvailableGens;
+
+	/** Guards m_AvailableGens and m_WorldIni against multithreaded access. */
 	QMutex m_Mtx;
+
+
+	/** Returns a cBiomeGen that can generate a new chunk's biomes.
+	Uses m_AvailableGens as a cache before creating a new generator. */
+	cBiomeGenPtr BioGenSource::getBiomeGen();
+
+	/** Puts the specified BiomeGen back to m_AvailableGens to make it available for next getBiomeGen() request.
+	Truncates m_AvailableGens if there are too many instances in there. */
+	void releaseBiomeGen(cBiomeGenPtr a_BiomeGen);
 };
 
 
@@ -52,7 +79,9 @@ class AnvilSource :
 public:
 	// TODO
 
+	// ChunkSource overrides:
 	virtual void getChunkBiomes(int a_ChunkX, int a_ChunkZ, ChunkPtr a_DestChunk) override;
+	virtual void reload() override {}
 };