1 files changed, 32 insertions, 1 deletions

diff --git a/src/LineBlockTracer.h b/src/LineBlockTracer.h
index 37493ce5c..2851cfbd7 100644
--- a/src/LineBlockTracer.h
+++ b/src/LineBlockTracer.h
@@ -33,6 +33,19 @@ class cLineBlockTracer :
 	typedef cBlockTracer super;
 
 public:
+	enum eLineOfSight
+	{
+		// Bit flags used for LineOfSightTrace's Sight parameter:
+		losAir = 1,    // Can see through air
+		losWater = 2,  // Can see through water
+		losLava = 4,   // Can see through lava
+
+		// Common combinations:
+		losAirWaterLava = losAir | losWater | losLava,
+		losAirWater = losAir | losWater,
+	};
+
+
 	cLineBlockTracer(cWorld & a_World, cCallbacks & a_Callbacks);
 
 	/** Traces one line between Start and End; returns true if the entire line was traced (until OnNoMoreHits()) */
@@ -46,6 +59,24 @@ public:
 	/** Traces one line between Start and End; returns true if the entire line was traced (until OnNoMoreHits()) */
 	static bool Trace(cWorld & a_World, cCallbacks & a_Callbacks, const Vector3d & a_Start, const Vector3d & a_End);
 
+	/** Returns true if the two positions are within line of sight (not obscured by blocks).
+	a_Sight specifies which blocks are considered transparent for the trace, is an OR-combination of eLineOfSight constants. */
+	static bool LineOfSightTrace(cWorld & a_World, const Vector3d & a_Start, const Vector3d & a_End, int a_Sight);
+
+	/** Traces until the first solid block is hit (or until end, whichever comes first.
+	If a solid block was hit, returns true and fills a_HitCoords, a_HitBlockCoords and a_HitBlockFace.
+	If a_End is encountered without hitting any solid block, returns false and doesn't touch a_HitCoords, a_HitBlockCoords nor a_HitBlockFace.
+	a_HitCoords is the exact coords of the hit,
+	a_HitBlockCoords are the coords of the solid block that was hit,
+	a_HitBlockFace is the face of the solid block that was hit. */
+	static bool FirstSolidHitTrace(
+		cWorld & a_World,
+		const Vector3d & a_Start, const Vector3d & a_End,
+		Vector3d & a_HitCoords,
+		Vector3i & a_HitBlockCoords,
+		eBlockFace & a_HitBlockFace
+	);
+
 protected:
 	/** The start point of the trace */
 	double m_StartX, m_StartY, m_StartZ;
@@ -63,7 +94,7 @@ protected:
 	int m_CurrentX, m_CurrentY, m_CurrentZ;
 
 	/** The face through which the current block has been entered */
-	char m_CurrentFace;
+	eBlockFace m_CurrentFace;
 
 
 	/** Adjusts the start point above the world to just at the world's top */