Expose getPointedThing to Lua

This commit introduces Raycast, a Lua user object, which can be
used to perform a raycast on the map. The ray is continuable, so one can
also get hidden nodes (for example to see trough glass).

2 files changed, 51 insertions, 13 deletions

diff --git a/src/util/pointedthing.cpp b/src/util/pointedthing.cpp
index f1f1d3f20..e5c5dcf4c 100644
--- a/src/util/pointedthing.cpp
+++ b/src/util/pointedthing.cpp
@@ -23,20 +23,47 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "../exceptions.h"
 #include <sstream>
 
+PointedThing::PointedThing(const v3s16 &under, const v3s16 &above,
+	const v3s16 &real_under, const v3f &point, const v3s16 &normal,
+	f32 distSq):
+	type(POINTEDTHING_NODE),
+	node_undersurface(under),
+	node_abovesurface(above),
+	node_real_undersurface(real_under),
+	intersection_point(point),
+	intersection_normal(normal),
+	distanceSq(distSq)
+{}
+
+PointedThing::PointedThing(s16 id, const v3f &point, const v3s16 &normal,
+	f32 distSq) :
+	type(POINTEDTHING_OBJECT),
+	object_id(id),
+	intersection_point(point),
+	intersection_normal(normal),
+	distanceSq(distSq)
+{}
+
 std::string PointedThing::dump() const
 {
 	std::ostringstream os(std::ios::binary);
-	if (type == POINTEDTHING_NOTHING) {
-		os<<"[nothing]";
-	} else if (type == POINTEDTHING_NODE) {
+	switch (type) {
+	case POINTEDTHING_NOTHING:
+		os << "[nothing]";
+		break;
+	case POINTEDTHING_NODE:
+	{
 		const v3s16 &u = node_undersurface;
 		const v3s16 &a = node_abovesurface;
-		os<<"[node under="<<u.X<<","<<u.Y<<","<<u.Z
-			<< " above="<<a.X<<","<<a.Y<<","<<a.Z<<"]";
-	} else if (type == POINTEDTHING_OBJECT) {
-		os<<"[object "<<object_id<<"]";
-	} else {
-		os<<"[unknown PointedThing]";
+		os << "[node under=" << u.X << "," << u.Y << "," << u.Z << " above="
+			<< a.X << "," << a.Y << "," << a.Z << "]";
+	}
+		break;
+	case POINTEDTHING_OBJECT:
+		os << "[object " << object_id << "]";
+		break;
+	default:
+		os << "[unknown PointedThing]";
 	}
 	return os.str();
 }
@@ -104,4 +131,3 @@ bool PointedThing::operator!=(const PointedThing &pt2) const
 {
 	return !(*this == pt2);
 }
-
diff --git a/src/util/pointedthing.h b/src/util/pointedthing.h
index 92c33968f..f63bcad9d 100644
--- a/src/util/pointedthing.h
+++ b/src/util/pointedthing.h
@@ -59,6 +59,11 @@ struct PointedThing
 	 */
 	v3s16 node_real_undersurface;
 	/*!
+	 * Only valid if type is POINTEDTHING_OBJECT.
+	 * The ID of the object the ray hit.
+	 */
+	s16 object_id = -1;
+	/*!
 	 * Only valid if type isn't POINTEDTHING_NONE.
 	 * First intersection point of the ray and the nodebox.
 	 */
@@ -71,12 +76,19 @@ struct PointedThing
 	 */
 	v3s16 intersection_normal;
 	/*!
-	 * Only valid if type is POINTEDTHING_OBJECT.
-	 * The ID of the object the ray hit.
+	 * Square of the distance between the pointing
+	 * ray's start point and the intersection point.
 	 */
-	s16 object_id = -1;
+	f32 distanceSq = 0;
 
+	//! Constructor for POINTEDTHING_NOTHING
 	PointedThing() {};
+	//! Constructor for POINTEDTHING_NODE
+	PointedThing(const v3s16 &under, const v3s16 &above,
+		const v3s16 &real_under, const v3f &point, const v3s16 &normal,
+		f32 distSq);
+	//! Constructor for POINTEDTHING_OBJECT
+	PointedThing(s16 id, const v3f &point, const v3s16 &normal, f32 distSq);
 	std::string dump() const;
 	void serialize(std::ostream &os) const;
 	void deSerialize(std::istream &is);