Rect.java

public class Rect {
    public final int x1;
    public final int y1;
    public final int x2;
    public final int y2;
    public final int height;
    public final int width;
    public int id; // assignable with no consequence?
    public boolean[] pointerTrail; // not actually a trail
    
    public Rect(int x1, int y1, int x2, int y2) {
        if (x2<x1 || y2<y1) throw new UnsupportedOperationException("INVALID RECTANGLE");
        this.x1 = x1;
        this.y1 = y1;
        this.x2 = x2;
        this.y2 = y2;
        this.height = y2 - y1;
        this.width = x2 - x1;
    }
    
    public Rect(int x1, int y1, int x2, int y2, int id) {
        this(x1,y1,x2,y2);
        this.id = id;
    }

    public static Rect place(int x, int y, int width, int height) {
        return new Rect(x,y,x+width,y+height);
    }
    
    // true if other is on the left
    public boolean touchLeft(Rect other) {
        return this.x1 == other.x2 && this.y1 < other.y2 && this.y2 > other.y1;
    }
    
    // true if other is below
    public boolean touchBottom(Rect other) {
        return this.y1 == other.y2 && this.x1 < other.x2 && this.x2 > other.x1;
    }
    
    public boolean overlaps(Rect other) {
        return  this.x2 > other.x1 && this.x1 < other.x2 &&
                this.y2 > other.y1 && this.y1 < other.y2;
        //if (r) System.out.println(this + " | " + other);
    }

    public String toString() {
        return "("+x1+","+y1+","+x2+","+y2+")";
    }
}