/* * ObstacleSim.java */package EDU.gatech.cc.is.simulation;import java.awt.*;import EDU.gatech.cc.is.util.Vec2;import EDU.gatech.cc.is.util.Units;import EDU.gatech.cc.is.communication.Message;import EDU.cmu.cs.coral.util.Polygon2;import EDU.cmu.cs.coral.util.Circle2;/** * an obstacle for simulation. * <P> * Copyright (c)2000 Tucker Balch * * @author Tucker Balch * @version $Revision: 1.4 $ */public class ObstacleSim extends Object implements SimulatedObject	{	protected Vec2	position;	protected	Color	foreground, background;	protected	SimulatedObject[] all_objects;	protected	int	visionclass;	protected	int	unique_id;	protected	double	RADIUS;	protected	double	lastx, lasty;	public	static final boolean DEBUG = false;	/**	 * Instantiate an <B>ObstacleSim</B> object.  Be sure	 * to also call init with proper values.	 * @see ObstacleSim#init	 */        public ObstacleSim()		{		position = new Vec2(0,0);		foreground = Color.black;		if (DEBUG) System.out.println("ObstacleSim: instantiated.");		}	        /**         * Initialize a <B>ObstacleSim</B> object.	 * This is called automatically by JavaBotSim.	 * @param xp	the x coordinate.	 * @param yp	the y coordinate.	 * @param t	ingored.	 * @param r	the radius.	 * @param f	the foreground color.	 * @param b	ignored.	 * @param v	the vision class.	 * @param i	the unique id.	 * @param s	random number seed.         */	public void init(double xp, double yp, double t, double r,		Color f, Color b, int v, int i, long s)		{		position = new Vec2(xp,yp);		RADIUS = r;		foreground = f;		background = b;		visionclass = v;		setID(i);		if (DEBUG) System.out.println("ObstacleSim: initialized"			+" at "+xp+","+yp);		}	/**	 * Take a simulated step;	 */	public void takeStep(long time_increment, SimulatedObject[] all_objs)		{		/*--- keep pointer to the other objects ---*/		all_objects = all_objs;		// that's all that's really necessary		}	public boolean isObstacle()		{		return(true);		}		public boolean isPushable()		{		return(false);		}		public boolean isPickupable()		{		return(false);		}	        public Vec2 getPosition()                {                return(new Vec2(position.x, position.y));                }	public Vec2 getClosestPoint(Vec2 from)		{		Vec2 tmp = new Vec2(position.x, position.y);		tmp.sub(from);		if (tmp.r < RADIUS)			tmp.setr(0);		else			tmp.setr(tmp.r-RADIUS);                Vec2 last = new Vec2(tmp.x, tmp.y);                last.add(from);                lastx = last.x;                lasty = last.y;		return(tmp);		}        /**	 * determine if the object is intersecting with a specified circle.	 * This is useful for obstacle avoidance and so on.	 * @param c the circle which may be intersecting the current object.	 * @return true if collision detected.         */	public boolean checkCollision(Circle2 c)	    {	    Vec2 closest = getClosestPoint(c.centre); // closest is a vector with origin at centre that leads to closest point on current object	    if (closest.r <= c.radius) // closest point is within c.radius of c.centre			{			return true;			}	    else 			{			return false;			}	    }        /**	 * determine if the object is intersecting with a specified polygon.	 * This is useful for obstacle avoidance and so on.	 * @param p the polygon which may be intersecting the current object.	 * @return true if collision detected.         */	public boolean checkCollision(Polygon2 p)		{		Vec2 vertex1, vertex2, vec1, vector2, closestPt;		int numberEdges = p.vertices.size(); // n edges if n vertices (as vertex n+1 wraps round to vertex 0)		double scale;		for (int i=0;i<numberEdges;i++)			{			vertex1 = (Vec2)p.vertices.elementAt(i);			vertex2 = (Vec2)p.vertices.elementAt((i+1)%numberEdges);			vertex1.sub(position);			vertex2.sub(position);			// if either vertex is within the circles radius you are colliding			if ((vertex1.r < RADIUS) || (vertex2.r < RADIUS))				{				return true;				} 			vertex1.add(position);			vertex2.add(position);			vec1 = new Vec2(vertex2);			vec1.sub(vertex1);			vector2 = new Vec2(position);			vector2.sub(vertex1);			scale = ((vec1.x*vector2.x)+(vec1.y*vector2.y))/((vec1.x*vec1.x)+(vec1.y*vec1.y));			closestPt = new Vec2(scale*vec1.x, scale*vec1.y);			closestPt.add(vertex1); // absolute position of closest point			closestPt.sub(position); // position of closest point relative to centre of current object			if (closestPt.r < RADIUS)				{				// now need to check if closestPt lies between vertex1 and vertex2				// i.e. it could lie on vector between them but outside of them				if ( (scale > 0.0) && (scale < 1.0) )					{					return true;					}				}			}		return false; // closest point to object on each edge of polygon not within object					}	public Vec2 getCenter(Vec2 from)		{		Vec2 tmp = new Vec2(position.x, position.y);		tmp.sub(from);		return(tmp);		}	public void push(Vec2 d, Vec2 v)		{		// sorry no pushee obstacles!		}	public void pickUp(SimulatedObject o)		{		// sorry no pickupee obstacles!		}	public void receive(Message m)		{		// default is to ignore messages.		}	public void putDown(Vec2 p)		{		// sorry no put downee obstacles!		}	public void setVisionClass(int v)		{		visionclass = v;		}	public int getVisionClass()		{		return(visionclass);		}	public void setID(int i)		{		unique_id = i;		}	public int getID()		{		return(unique_id);		}	public void quit()		{		}        /**         * Draw the objects's ID.         */        public void drawID(Graphics g, int w, int h,                double t, double b, double l, double r)                {                //skip for obstacles                }        /**         * Draw the object as an icon.         * Default is just to do a regular draw.         */        public void drawIcon(Graphics g, int w, int h,                double t, double b, double l, double r)                {                draw(g, w, h, t, b, l, r);                }        /**         * Draw the objects's State.         */        public void drawState(Graphics g, int w, int h,                double t, double b, double l, double r)                {                double meterspp = (r - l) / (double)w;                if (DEBUG) System.out.println("meterspp "+meterspp);                int x1pix = (int)((lastx - l) / meterspp);                int y1pix = (int)((double)h - ((lasty - b) / meterspp));                if (DEBUG) System.out.println("line at"+                        " at "+x1pix+","+y1pix);                /*--- draw the oval ---*/                g.setColor(background);                g.fillOval(x1pix-2, y1pix-2, 4, 4);                }        /**         * Set the length of the trail (in movement steps).         * Non-robots can ignore this.          * @param l int, the length of the trail.         */        public void setTrailLength(int l)		{		//ignore		}        /**         * Clear the trail.         * Non-robots can ignore this.         */        public void clearTrail()		{		//ignore		}        /**         * Draw the objects's Trail.         */        public void drawTrail(Graphics g, int w, int h,                double t, double b, double l, double r)                {		//ignore for obstacles                }	/**	 * Draw the object.	 */	public void draw(Graphics g, int w, int h,		double t, double b, double l, double r)		{		double meterspp = (r - l) / (double)w;		if (DEBUG) System.out.println("meterspp "+meterspp);		int radius = (int)(RADIUS / meterspp);		int xpix = (int)((position.x - l) / meterspp);		int ypix = (int)((double)h - ((position.y - b) / meterspp));		if (DEBUG) System.out.println("robot at"+			" at "+xpix+","+ypix);		/*--- draw the main body ---*/		g.setColor(foreground);		g.fillOval(xpix - radius, ypix - radius,			radius + radius, radius + radius);		}	/**	 * Draw the object in a specific spot.	 */	public void draw(Vec2 pos, Graphics g, int w, int h,		double t, double b, double l, double r)		{		Vec2 old_pos = position;		position = pos;		draw(g,w,h,t,b,l,r);		position = old_pos;		}	}