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).

1 files changed, 37 insertions, 1 deletions

diff --git a/src/raycast.cpp b/src/raycast.cpp
index 58102c993..42cc22587 100644
--- a/src/raycast.cpp
+++ b/src/raycast.cpp
@@ -17,11 +17,47 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
+#include "raycast.h"
 #include "irr_v3d.h"
 #include "irr_aabb3d.h"
+#include "constants.h"
+
+bool RaycastSort::operator() (const PointedThing &pt1,
+	const PointedThing &pt2) const
+{
+	// "nothing" can not be sorted
+	assert(pt1.type != POINTEDTHING_NOTHING);
+	assert(pt2.type != POINTEDTHING_NOTHING);
+	// returns false if pt1 is nearer than pt2
+	if (pt1.distanceSq < pt2.distanceSq) {
+		return false;
+	} else if (pt1.distanceSq == pt2.distanceSq) {
+		// Sort them to allow only one order
+		if (pt1.type == POINTEDTHING_OBJECT)
+			return (pt2.type == POINTEDTHING_OBJECT
+				&& pt1.object_id < pt2.object_id);
+		else
+			return (pt2.type == POINTEDTHING_OBJECT
+				|| pt1.node_undersurface < pt2.node_undersurface);
+	}
+	return true;
+}
+
+
+RaycastState::RaycastState(const core::line3d<f32> &shootline,
+	bool objects_pointable, bool liquids_pointable) :
+	m_shootline(shootline),
+	m_iterator(shootline.start / BS, shootline.getVector() / BS),
+	m_previous_node(m_iterator.m_current_node_pos),
+	m_objects_pointable(objects_pointable),
+	m_liquids_pointable(liquids_pointable)
+{
+}
+
 
 bool boxLineCollision(const aabb3f &box, const v3f &start,
-		const v3f &dir, v3f *collision_point, v3s16 *collision_normal) {
+	const v3f &dir, v3f *collision_point, v3s16 *collision_normal)
+{
 	if (box.isPointInside(start)) {
 		*collision_point = start;
 		collision_normal->set(0, 0, 0);