Added new Qt-based biome visualiser.

Compile with Qt 5.1+

Tools/QtBiomeVisualiser/ChunkCache.cpp

@@ -0,0 +1,110 @@
+#include "Globals.h"
+#include "ChunkCache.h"
+#include <QMutexLocker>
+#include <QThreadPool>
+#include "ChunkSource.h"
+#include "ChunkLoader.h"
+
+
+
+
+
+ChunkCache::ChunkCache(QObject * parent) :
+	super(parent)
+{
+	m_Cache.setMaxCost(1024 * 1024 * 1024);  // 1 GiB of memory for the cache
+}
+
+
+
+
+
+ChunkPtr ChunkCache::fetch(int a_ChunkX, int a_ChunkZ)
+{
+	// Retrieve from the cache:
+	quint32 hash = getChunkHash(a_ChunkX, a_ChunkZ);
+	ChunkPtr * res;
+	{
+		QMutexLocker lock(&m_Mtx);
+		res = m_Cache[hash];
+		// If succesful and chunk loaded, return the retrieved value:
+		if ((res != nullptr) && (*res)->isValid())
+		{
+			return *res;
+		}
+	}
+
+	// If the chunk is in cache but not valid, it means it has been already queued for rendering, do nothing now:
+	if (res != nullptr)
+	{
+		return ChunkPtr(nullptr);
+	}
+
+	// There's no such item in the cache, create it now:
+	res = new ChunkPtr(new Chunk);
+	if (res == nullptr)
+	{
+		return ChunkPtr(nullptr);
+	}
+	{
+		QMutexLocker lock(&m_Mtx);
+		m_Cache.insert(hash, res, sizeof(Chunk));
+	}
+
+	// Queue the chunk for rendering:
+	queueChunkRender(a_ChunkX, a_ChunkZ, *res);
+
+	// Return failure, the chunk is not yet rendered:
+	return ChunkPtr(nullptr);
+}
+
+
+
+
+
+void ChunkCache::setChunkSource(std::shared_ptr<ChunkSource> a_ChunkSource)
+{
+	// Replace the chunk source:
+	m_ChunkSource = a_ChunkSource;
+
+	// Clear the cache:
+	QMutexLocker lock(&m_Mtx);
+	m_Cache.clear();
+}
+
+
+
+
+
+void ChunkCache::gotChunk(int a_ChunkX, int a_ChunkZ)
+{
+	emit chunkAvailable(a_ChunkX, a_ChunkZ);
+}
+
+
+
+
+
+quint32 ChunkCache::getChunkHash(int a_ChunkX, int a_ChunkZ)
+{
+	// Simply join the two coords into a single int
+	// The coords will never be larger than 16-bits, so we can do this safely
+	return (((static_cast<quint32>(a_ChunkX) & 0xffff) << 16) | (static_cast<quint32>(a_ChunkZ) & 0xffff));
+}
+
+
+
+
+
+void ChunkCache::queueChunkRender(int a_ChunkX, int a_ChunkZ, ChunkPtr & a_Chunk)
+{
+	// Create a new loader task:
+	ChunkLoader * loader = new ChunkLoader(a_ChunkX, a_ChunkZ, a_Chunk, m_ChunkSource);
+	connect(loader, SIGNAL(loaded(int, int)), this, SLOT(gotChunk(int, int)));
+
+	QThreadPool::globalInstance()->start(loader);
+}
+
+
+
+