1 files changed, 89 insertions, 0 deletions
diff --git a/src/raycast.cpp b/src/raycast.cpp
new file mode 100644
index 000000000..58102c993
--- /dev/null
+++ b/src/raycast.cpp
@@ -0,0 +1,89 @@
+/*
+Minetest
+Copyright (C) 2016 juhdanad, Daniel Juhasz <juhdanad@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "irr_v3d.h"
+#include "irr_aabb3d.h"
+
+bool boxLineCollision(const aabb3f &box, const v3f &start,
+		const v3f &dir, v3f *collision_point, v3s16 *collision_normal) {
+	if (box.isPointInside(start)) {
+		*collision_point = start;
+		collision_normal->set(0, 0, 0);
+		return true;
+	}
+	float m = 0;
+
+	// Test X collision
+	if (dir.X != 0) {
+		if (dir.X > 0)
+			m = (box.MinEdge.X - start.X) / dir.X;
+		else
+			m = (box.MaxEdge.X - start.X) / dir.X;
+
+		if (m >= 0 && m <= 1) {
+			*collision_point = start + dir * m;
+			if ((collision_point->Y >= box.MinEdge.Y)
+					&& (collision_point->Y <= box.MaxEdge.Y)
+					&& (collision_point->Z >= box.MinEdge.Z)
+					&& (collision_point->Z <= box.MaxEdge.Z)) {
+				collision_normal->set((dir.X > 0) ? -1 : 1, 0, 0);
+				return true;
+			}
+		}
+	}
+
+	// Test Y collision
+	if (dir.Y != 0) {
+		if (dir.Y > 0)
+			m = (box.MinEdge.Y - start.Y) / dir.Y;
+		else
+			m = (box.MaxEdge.Y - start.Y) / dir.Y;
+
+		if (m >= 0 && m <= 1) {
+			*collision_point = start + dir * m;
+			if ((collision_point->X >= box.MinEdge.X)
+					&& (collision_point->X <= box.MaxEdge.X)
+					&& (collision_point->Z >= box.MinEdge.Z)
+					&& (collision_point->Z <= box.MaxEdge.Z)) {
+				collision_normal->set(0, (dir.Y > 0) ? -1 : 1, 0);
+				return true;
+			}
+		}
+	}
+
+	// Test Z collision
+	if (dir.Z != 0) {
+		if (dir.Z > 0)
+			m = (box.MinEdge.Z - start.Z) / dir.Z;
+		else
+			m = (box.MaxEdge.Z - start.Z) / dir.Z;
+
+		if (m >= 0 && m <= 1) {
+			*collision_point = start + dir * m;
+			if ((collision_point->X >= box.MinEdge.X)
+					&& (collision_point->X <= box.MaxEdge.X)
+					&& (collision_point->Y >= box.MinEdge.Y)
+					&& (collision_point->Y <= box.MaxEdge.Y)) {
+				collision_normal->set(0, 0, (dir.Z > 0) ? -1 : 1);
+				return true;
+			}
+		}
+	}
+	return false;
+}