Implemented nether portal scanning code.

src/NetherPortalScanner.h

@@ -0,0 +1,75 @@
+
+#pragma once
+
+#include "Vector3.h"
+#include "ChunkStay.h"
+
+
+class cEntity;
+class cWorld;
+
+
+
+
+
+// This is the chunk stay which finds nearby nether portals
+class cNetherPortalScanner : public cChunkStay
+{
+public:
+	cNetherPortalScanner(cEntity * a_MovingEntity, cWorld * a_DestinationWorld, Vector3d a_DestPosition, int a_MaxY);
+	virtual void OnChunkAvailable(int a_ChunkX, int a_ChunkY) override;
+	virtual bool OnAllChunksAvailable(void) override;
+	virtual void OnDisabled(void) override;
+
+	enum class Direction
+	{
+		X,
+		Y
+	};
+
+private:
+
+	/** Length and height, including the obsidian. */
+	static const int PortalLength = 4;
+	static const int PortalHeight = 5;
+
+	static const int SearchRadius = 128;
+	static const int BuildSearchRadius = 16;
+
+	/** The width of a solid base to search for when building. */
+	static const int SearchSolidBaseWidth = 3;
+
+	/** Where to place the player out from the face and across the face */
+	const double OutOffset = 1.5;
+	const double AcrossOffset = 0.5;
+
+	/** Builds a portal. */
+	void BuildNetherPortal(Vector3i a_Location, Direction a_Direction, bool a_IncludePlatform);
+
+	/** Whether the given location is a valid location to build a portal. */
+	bool IsValidBuildLocation(Vector3i a_BlockPosition);
+
+	/** The entity that's being moved. */
+	cEntity * m_Entity;
+
+	/** The world we're moving the entity to. */
+	cWorld * m_World;
+
+	/** Whether we found a portal during the loading of the chunks. */
+	bool m_FoundPortal;
+
+	/** Whether to build a platform. True if we couldn't build the portal on solid ground */
+	bool m_BuildPlatform;
+
+	/** The direction of the portal. */
+	Direction m_Dir;
+
+	/** The position of the pre-existing portal. */
+	Vector3i m_PortalLoc;
+
+	/** The center of the search area */
+	Vector3d m_Position;
+
+	/** The maximum Y to scan to */
+	int m_MaxY;
+};