QtBiomeVisualiser: Added multithreading.

For some reason this makes the UI less responsive.

Tools/QtBiomeVisualiser/ChunkSource.cpp

@@ -1,6 +1,8 @@
 #include "Globals.h"
 #include "ChunkSource.h"
+#include <QThread>
 #include "Generating/BioGen.h"
+#include "inifile/iniFile.h"
 
 
 
@@ -138,9 +140,12 @@ static void biomesToImage(cChunkDef::BiomeMap & a_Biomes, Chunk::Image & a_Image
 ////////////////////////////////////////////////////////////////////////////////
 // BioGenSource:
 
-BioGenSource::BioGenSource(cBiomeGen * a_BiomeGen) :
-	m_BiomeGen(a_BiomeGen)
+BioGenSource::BioGenSource(QString a_WorldIniPath) :
+	m_WorldIniPath(a_WorldIniPath),
+	m_WorldIni(new cIniFile),
+	m_Mtx(QMutex::Recursive)
 {
+	reload();
 }
 
 
@@ -149,11 +154,14 @@ BioGenSource::BioGenSource(cBiomeGen * a_BiomeGen) :
 
 void BioGenSource::getChunkBiomes(int a_ChunkX, int a_ChunkZ, ChunkPtr a_DestChunk)
 {
-	// TODO: To make use of multicore machines, we need multiple copies of the biomegen
-	// Right now we have only one, so we can let only one thread use it (hence the mutex)
-	QMutexLocker lock(&m_Mtx);
+	cBiomeGenPtr biomeGen;
+	{
+		QMutexLocker lock(&m_Mtx);
+		biomeGen = getBiomeGen();
+	}
 	cChunkDef::BiomeMap biomes;
-	m_BiomeGen->GenBiomes(a_ChunkX, a_ChunkZ, biomes);
+	biomeGen->GenBiomes(a_ChunkX, a_ChunkZ, biomes);
+	releaseBiomeGen(biomeGen);
 	Chunk::Image img;
 	biomesToImage(biomes, img);
 	a_DestChunk->setImage(img);
@@ -162,3 +170,57 @@ void BioGenSource::getChunkBiomes(int a_ChunkX, int a_ChunkZ, ChunkPtr a_DestChu
 
 
 
+
+void BioGenSource::reload()
+{
+	{
+		QMutexLocker lock(&m_Mtx);
+		if (!m_WorldIni->ReadFile(m_WorldIniPath.toStdString()))
+		{
+			return;
+		}
+		m_AvailableGens.clear();
+	}
+}
+
+
+
+
+cBiomeGenPtr BioGenSource::getBiomeGen()
+{
+	QMutexLocker lock(&m_Mtx);
+
+	// Return a generator from the cache, if available:
+	if (!m_AvailableGens.empty())
+	{
+		cBiomeGenPtr res = m_AvailableGens.back();
+		m_AvailableGens.pop_back();
+		return res;
+	}
+
+	// No generator in cache available, create a new one:
+	int seed = m_WorldIni->GetValueSetI("Seed", "Seed", 0);
+	bool unused = false;
+	return cBiomeGenPtr(cBiomeGen::CreateBiomeGen(*m_WorldIni, seed, unused));
+}
+
+
+
+
+
+void BioGenSource::releaseBiomeGen(cBiomeGenPtr a_BiomeGen)
+{
+	QMutexLocker lock(&m_Mtx);
+	m_AvailableGens.push_back(a_BiomeGen);
+
+	// Trim the cache if there are too many gens:
+	int wantedNumGens = QThread::idealThreadCount();
+	if (m_AvailableGens.size() > (size_t)(4 * wantedNumGens))
+	{
+		m_AvailableGens.resize(wantedNumGens);
+	}
+}
+
+
+
+

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 {}
 };
 
 

Tools/QtBiomeVisualiser/MainWindow.cpp

@@ -39,19 +39,7 @@ MainWindow::~MainWindow()
 void MainWindow::generate()
 {
 	QString worldIni = QFileDialog::getOpenFileName(this, tr("Open world.ini"), QString(), tr("world.ini (world.ini)"));
-	cIniFile ini;
-	if (!ini.ReadFile(worldIni.toStdString()))
-	{
-		return;
-	}
-	int seed = ini.GetValueSetI("Seed", "Seed", 0);
-	bool unused = false;
-	cBiomeGen * biomeGen = cBiomeGen::CreateBiomeGen(ini, seed, unused);
-	if (biomeGen == nullptr)
-	{
-		return;
-	}
-	m_BiomeView->setChunkSource(std::shared_ptr<BioGenSource>(new BioGenSource(biomeGen)));
+	m_BiomeView->setChunkSource(std::shared_ptr<BioGenSource>(new BioGenSource(worldIni)));
 	m_BiomeView->redraw();
 }