diff --git a/source/src/physics.cpp b/source/src/physics.cpp
index bfb02623..6079df6f 100644
--- a/source/src/physics.cpp
+++ b/source/src/physics.cpp
@@ -59,6 +59,17 @@ float raycube(const vec &o, const vec &ray, vec &surface)
     return dist;    
 } 
 
+bool raycubelos(const vec &from, const vec &to, float margin)
+{
+    vec dir(to);
+    dir.sub(from);
+    float limit = dir.magnitude();
+    dir.mul(1.0f/limit);
+    vec surface;
+    float dist = raycube(from, dir, surface);
+    return dist > max(limit - margin, 0.0f);
+}
+
 physent *hitplayer = NULL;
 
 bool plcollide(physent *d, physent *o, float &headspace, float &hi, float &lo)          // collide with physent
diff --git a/source/src/protos.h b/source/src/protos.h
index 88206bb8..916910f2 100644
--- a/source/src/protos.h
+++ b/source/src/protos.h
@@ -499,6 +499,7 @@ extern uchar *readmcfggz(char *name, int *size, int *sizegz);
 
 // physics
 extern float raycube(const vec &o, const vec &ray, vec &surface);
+extern bool raycubelos(const vec &from, const vec &to, float margin = 0);
 extern void moveplayer(physent *pl, int moveres, bool local);
 extern void moveplayer(physent *pl, int moveres, bool local, int curtime);
 extern void movebounceent(bounceent *p, int moveres, bool local);