//  Kestrel in a swarm
//
//  Author  Matthew Caryl
//  Created 14.12.96
//
//  Although under copywrite to the author (Matthew Caryl) this code can be copied and modified for non-commercial
//  purposes as long as any derivatives contain this condition.

package Swarm;

import java.awt.Rectangle;

final class Kestrel extends Bot {
    //
    // Private interface
    //

    // global kestrel data polar coordinates
    private static final int        radius = 10;
    private static final int        collision_radius = radius + 1;
    private static final float      forwardSpeed = 4;
    private static final float      angularSpeed = PI / 320f;
    private static final float[]    aBodyOutline = {0f, 2.36f, 3.93f, 0f};
    private static final float[]    rBodyOutline = {radius, radius, radius, radius};
    
    // individual kestrel data
    private int                 wait = 0;
    private static final int    DIGESTION_TIME = 50;

    //
    // public interface of kestrel to World object
    //
    
    // retrieve outlines of kestrel components
    public int[][][] outline() {
        outline[0][0][0] = (int) (x + radius * Math.sin(heading + 0f));
        outline[0][1][0] = (int) (y - radius * Math.cos(heading + 0f));
        outline[0][0][1] = (int) (x + radius * Math.sin(heading + 2.36f));
        outline[0][1][1] = (int) (y - radius * Math.cos(heading + 2.36f));
        outline[0][0][2] = (int) (x + radius * Math.sin(heading + 3.93f));
        outline[0][1][2] = (int) (y - radius * Math.cos(heading + 3.93f));
        outline[0][0][3] = outline[0][0][0]; outline[0][1][3] = outline[0][1][0];
        return outline;
        }
    
    // retrieve bounding rectangle of kestrel components
    public Rectangle bounds() {
        bounds.reshape((int) (x - radius), (int) (y - radius), (int) (2 * radius), (int) (2 * radius));
        return bounds;
        }
    
    // retrieve the maximum radius of the kestrel
    public int radius() {
        return collision_radius;
        }
    
    // initialise kestrel
    public Kestrel(World W, int X, int Y) {
        world = W;
        x = X;
        y = Y;
        heading = (float) world.random().range(360) / (float) 180 * PI;
        color = randomColor();
        }
    
    // single move
    public void action() {
        remember(); // store current location in case of collision
        
        if (neighbours[0] instanceof Sparrow) {
            // eat sparrows if hungrey and close enough
            if (wait == 0 && separation(neighbours[0]) < sqr(collision_radius + neighbours[0].radius())) {
                ((Sparrow) neighbours[0]).kill();
                wait = DIGESTION_TIME;
                }
            // otherwise fly towards closest
            else {
                float sp = angle(neighbours[0].x(), neighbours[0].y());
                
                heading -= angularSpeed * sp / QUARTERPI;
                }
            }
        
        // appetite increases
        if (wait > 0)
            wait--;
        
        // move forward
        x += Math.sin(heading) * forwardSpeed;
        y -= Math.cos(heading) * forwardSpeed;
        
        normalise(); // restrict heading to [0, 360]
        }
    }