Distance.java

gehe zur Dokumentation dieser Datei

package de.lathanda.eos.game.geom;
 
public class Distance {
 
    public static double distance(Shape a, Shape b) {
        //yes this is ugly, but java doesn't support polymorph parameters
        //and i don't know a better solution atm.
        switch (a.getOutlineType()) {
            case DOT:
                return b.getDistance(a.p);
            case GROUP:
                return groupOutline((ShapeGroup) a, b);
            case RECTANGLE:
                switch (b.getOutlineType()) {
                    case RECTANGLE:
                        return polygonPolygon((Rectangle) b, (Rectangle) a);
                    case POLYGON:
                        return polygonPolygon((Rectangle) a, (Polygon) b);
                    case CIRCLE:
                        return a.getDistance(b.p) - ((Circle) b).radius;
                    case DOT:
                        return a.getDistance(b.p);
                    case GROUP:
                        return groupOutline((ShapeGroup) b, a);
                    case UNDEFINED:
                        throw new RuntimeException("unknown outline typ!");
                }
            case POLYGON:
                switch (b.getOutlineType()) {
                    case RECTANGLE:
                        return polygonPolygon((Rectangle) b, (Polygon) a);
                    case POLYGON:
                        return polygonPolygon((Polygon) a, (Polygon) b);
                    case CIRCLE:
                        return a.getDistance(b.p) - ((Circle) b).radius;
                    case DOT:
                        return a.getDistance(b.p);
                    case GROUP:
                        return groupOutline((ShapeGroup) b, a);
                    case UNDEFINED:
                        throw new RuntimeException("unknown outline typ!");
                }
            case CIRCLE:
                return a.getDistance(b.p) - ((Circle) b).radius;
            case UNDEFINED:
                throw new RuntimeException("unknown outline typ!");
        }
        throw new RuntimeException("unknown outline typ!");
    }
 
    private static double groupOutline(ShapeGroup a, Shape b) {
        double distance = Double.POSITIVE_INFINITY;
        for (Shape o : a.getOutlines()) {
            distance = Math.min(o.distance(b), distance);
        }
        return distance;
    }
 
    private static double polygonPolygon(Polygon p1, Polygon p2) {
        double distance;
        if (p1.intersects(p2)) {
            distance = Double.NEGATIVE_INFINITY;
            for (int i = p1.coordinates_final_x.length; i-- > 0;) {
                distance = Math.max(distance, p2.getDistance(
                        p1.coordinates_final_x[i],
                        p1.coordinates_final_y[i]));
            }
            for (int i = p2.coordinates_final_x.length; i-- > 0;) {
                distance = Math.max(distance, p1.getDistance(
                        p2.coordinates_final_x[i],
                        p2.coordinates_final_y[i]));
            }
            distance = Math.min(distance, 0);
        } else {
            distance = Double.POSITIVE_INFINITY;
            for (int i = p1.coordinates_final_x.length; i-- > 0;) {
                distance = Math.min(distance, p2.getDistance(
                        p1.coordinates_final_x[i],
                        p1.coordinates_final_y[i]));
            }
            for (int i = p2.coordinates_final_x.length; i-- > 0;) {
                distance = Math.min(distance, p1.getDistance(
                        p2.coordinates_final_x[i],
                        p2.coordinates_final_y[i]));
            }
        }
        return distance;
    }
}