2 files changed, 16 insertions, 6 deletions

diff --git a/source/BoundingBox.cpp b/source/BoundingBox.cpp
index e2b8c313e..d8a1bc679 100644
--- a/source/BoundingBox.cpp
+++ b/source/BoundingBox.cpp
@@ -239,42 +239,50 @@ bool cBoundingBox::CalcLineIntersection(const Vector3d & a_Line1, const Vector3d
 
 bool cBoundingBox::CalcLineIntersection(const Vector3d & a_Min, const Vector3d & a_Max, const Vector3d & a_Line1, const Vector3d & a_Line2, double & a_LineCoeff, char & a_Face)
 {
+	if (IsInside(a_Min, a_Max, a_Line1))
+	{
+		// The starting point is inside the bounding box.
+		a_LineCoeff = 0;
+		a_Face = BLOCK_FACE_YM;  // Make it look as the top face was hit, although none really are.
+		return true;
+	}
+	
 	char Face = 0;
 	double Coeff = Vector3d::NO_INTERSECTION;
 	
 	// Check each individual bbox face for intersection with the line, remember the one with the lowest coeff
 	double c = a_Line1.LineCoeffToXYPlane(a_Line2, a_Min.z);
-	if ((c < Coeff) && IsInside(a_Min, a_Max, a_Line1 + (a_Line2 - a_Line1) * c))
+	if ((c >= 0) && (c < Coeff) && IsInside(a_Min, a_Max, a_Line1 + (a_Line2 - a_Line1) * c))
 	{
 		Face = (a_Line1.z > a_Line2.z) ? BLOCK_FACE_ZP : BLOCK_FACE_ZM;
 		Coeff = c;
 	}
 	c = a_Line1.LineCoeffToXYPlane(a_Line2, a_Max.z);
-	if ((c < Coeff) && IsInside(a_Min, a_Max, a_Line1 + (a_Line2 - a_Line1) * c))
+	if ((c >= 0) && (c < Coeff) && IsInside(a_Min, a_Max, a_Line1 + (a_Line2 - a_Line1) * c))
 	{
 		Face = (a_Line1.z > a_Line2.z) ? BLOCK_FACE_ZP : BLOCK_FACE_ZM;
 		Coeff = c;
 	}
 	c = a_Line1.LineCoeffToXZPlane(a_Line2, a_Min.y);
-	if ((c < Coeff) && IsInside(a_Min, a_Max, a_Line1 + (a_Line2 - a_Line1) * c))
+	if ((c >= 0) && (c < Coeff) && IsInside(a_Min, a_Max, a_Line1 + (a_Line2 - a_Line1) * c))
 	{
 		Face = (a_Line1.y > a_Line2.y) ? BLOCK_FACE_YP : BLOCK_FACE_YM;
 		Coeff = c;
 	}
 	c = a_Line1.LineCoeffToXZPlane(a_Line2, a_Max.y);
-	if ((c < Coeff) && IsInside(a_Min, a_Max, a_Line1 + (a_Line2 - a_Line1) * c))
+	if ((c >= 0) && (c >= 0) && (c < Coeff) && IsInside(a_Min, a_Max, a_Line1 + (a_Line2 - a_Line1) * c))
 	{
 		Face = (a_Line1.y > a_Line2.y) ? BLOCK_FACE_YP : BLOCK_FACE_YM;
 		Coeff = c;
 	}
 	c = a_Line1.LineCoeffToYZPlane(a_Line2, a_Min.x);
-	if ((c < Coeff) && IsInside(a_Min, a_Max, a_Line1 + (a_Line2 - a_Line1) * c))
+	if ((c >= 0) && (c < Coeff) && IsInside(a_Min, a_Max, a_Line1 + (a_Line2 - a_Line1) * c))
 	{
 		Face = (a_Line1.x > a_Line2.x) ? BLOCK_FACE_XP : BLOCK_FACE_XM;
 		Coeff = c;
 	}
 	c = a_Line1.LineCoeffToYZPlane(a_Line2, a_Max.x);
-	if ((c < Coeff) && IsInside(a_Min, a_Max, a_Line1 + (a_Line2 - a_Line1) * c))
+	if ((c >= 0) && (c < Coeff) && IsInside(a_Min, a_Max, a_Line1 + (a_Line2 - a_Line1) * c))
 	{
 		Face = (a_Line1.x > a_Line2.x) ? BLOCK_FACE_XP : BLOCK_FACE_XM;
 		Coeff = c;
diff --git a/source/BoundingBox.h b/source/BoundingBox.h
index cfaf6a318..ff9963989 100644
--- a/source/BoundingBox.h
+++ b/source/BoundingBox.h
@@ -64,11 +64,13 @@ public:
 	
 	/** Returns true if this bounding box is intersected by the line specified by its two points
 	Also calculates the distance along the line in which the intersection occurs (0 .. 1)
+	Only forward collisions (a_LineCoeff >= 0) are returned.
 	*/
 	bool CalcLineIntersection(const Vector3d & a_Line1, const Vector3d & a_Line2, double & a_LineCoeff, char & a_Face);
 	
 	/** Returns true if the specified bounding box is intersected by the line specified by its two points
 	Also calculates the distance along the line in which the intersection occurs (0 .. 1) and the face hit (BLOCK_FACE_ constants)
+	Only forward collisions (a_LineCoeff >= 0) are returned.
 	*/
 	static bool CalcLineIntersection(const Vector3d & a_Min, const Vector3d & a_Max, const Vector3d & a_Line1, const Vector3d & a_Line2, double & a_LineCoeff, char & a_Face);