--- a/src/PhysicsObject.cc	Mon Dec 08 15:02:05 2008 +0000
+++ b/src/PhysicsObject.cc	Mon Dec 08 15:37:34 2008 +0000
@@ -9,6 +9,7 @@
             float collision_elasticity, bool enabled) :
     world(world), 
     position(position), 
+    previousPosition(position),
     velocity(velocity), 
     mass(mass), 
     inAir(true), 
@@ -79,9 +80,8 @@
 void PhysicsObject::walk (TimeMS dt, bool right) {
     float velocity = PLAYER_WALK_SPEED;
     float walkAmount = (velocity*dt)/1000;
-    Vector reached = this->position;
-    while (walkAmount > 0 && !this->inAir) {
-        this->position = walk_one_step((1 < walkAmount ? 1 : walkAmount), right);
+    while (walkAmount > 0){// && !this->inAir) {
+        setPosition (walk_one_step((1 < walkAmount ? 1 : walkAmount), right));
         walkAmount--;
     }
     // TODO: Should the remaining walkAmount be handled somehow?
@@ -240,11 +240,11 @@
             // This means everything was ok, so no need to do anything
         }
 
-        this->position = newPosition;
+        setPosition (newPosition);
 
     } else {
         newPosition = reached;
-        this->position = newPosition;
+        setPosition (newPosition);
 
         // the following may delete this object, so it must be the last thing called
         onCollision(collisionPoint, NULL);
@@ -327,7 +327,7 @@
 }
 
 void PhysicsObject::updatePhysics (Vector position, Vector velocity, bool inAir, FacingDirection facing, float aim) {
-    this->position = position;
+    setPosition (position);
     this->velocity = velocity;
     this->inAir = inAir;
     this->facing = facing;
@@ -338,6 +338,15 @@
     return position;
 }
     
+Vector PhysicsObject::getPreviousPosition (void) const {
+    return previousPosition;
+}
+    
+void PhysicsObject::setPosition (Vector pos) {
+    this->previousPosition = this->position;
+    this->position = pos;
+}
+    
 PixelCoordinate PhysicsObject::getCoordinate (void) const {
     return world.getPixelCoordinate(position);
 }

--- a/src/PhysicsObject.hh	Mon Dec 08 15:02:05 2008 +0000
+++ b/src/PhysicsObject.hh	Mon Dec 08 15:37:34 2008 +0000
@@ -32,6 +32,7 @@
 
 protected:
     Vector position;
+    Vector previousPosition;
     Vector velocity;
     float mass;
     bool inAir; // Is the object "on the ground"
@@ -177,6 +178,20 @@
     Vector getPosition (void) const;
 
     /**
+     * Set previous object position.
+     *
+     * @param Position vector
+     */
+    void setPosition (Vector pos);
+
+    /**
+     * Get previous object position.
+     *
+     * @return Position vector
+     */
+    Vector getPreviousPosition (void) const;
+
+    /**
      * Get current object screen coordinates
      *
      * @return PixelCoordinate position

--- a/src/Rope.cc	Mon Dec 08 15:02:05 2008 +0000
+++ b/src/Rope.cc	Mon Dec 08 15:37:34 2008 +0000
@@ -24,7 +24,7 @@
     length = ROPE_LENGTH;
     
     // copy position + velocity from player
-    position = player.getPosition();
+    setPosition (player.getPosition());
     velocity = player.getVelocity() + player.getDirection() * ROPE_VELOCITY;
     
     // we are FLYING
@@ -45,7 +45,7 @@
         
     // Ropes location will be used as the pivot point, so move the location to the collisionPoint.
     // Currently the position is something like one pixel away from the collisionPoint where there isn't ground.
-    this->position = collisionPoint;
+    setPosition (collisionPoint);
 
     // set player's pivot
     player.setPivot(this);

--- a/src/Terrain.cc	Mon Dec 08 15:02:05 2008 +0000
+++ b/src/Terrain.cc	Mon Dec 08 15:37:34 2008 +0000
@@ -179,7 +179,7 @@
 
 PixelCoordinate Terrain::getPixelCoordinate (Vector point) const {
     // XXX: assume 1:1
-    return PixelCoordinate((unsigned int) point.x, (unsigned int) point.y);
+    return PixelCoordinate((int) point.x, (int) point.y);
 }
 
 PixelCoordinate Terrain::getDimensions (void) const {