SimplePathChecker.java

package com.osroyale.game.world.pathfinding.path;
 
import com.osroyale.game.world.Interactable;
import com.osroyale.game.world.entity.mob.Mob;
import com.osroyale.game.world.position.Position;
import com.osroyale.util.Utility;

 
public class SimplePathChecker extends PathFinder {
    private static final SimplePathChecker SIMPLE_PATH_CHECKER = new SimplePathChecker();
 
    @Override
    public Path find(Mob source, Position end, int targetWidth, int targetLength) {
        /* empty path */
        return new Path(null);
    }
 
    public static boolean checkLine(Interactable source, Interactable target) {
        Position targetPosition = Utility.findBestInside(source, target);
        return SIMPLE_PATH_CHECKER.check(source.getPosition(), targetPosition, source.width(), false);
    }
 
    public static boolean checkLine(Interactable source, Position target) {
        return SIMPLE_PATH_CHECKER.check(source.getPosition(), target, source.width(), false);
    }
 
    public static boolean checkProjectile(Interactable source, Interactable target) {
        Position targetPosition = Utility.findBestInside(source, target);
        return SIMPLE_PATH_CHECKER.check(source.getPosition(), targetPosition, Math.max(1, Math.max(source.width(), source.length())), true);
    }

    private boolean check(Position start, Position end, int size, boolean projectile) {
        int dx = end.getX() - start.getX();
        int dy = end.getY() - start.getY();
        int xSignum = Integer.signum(dx);
        int ySignum = Integer.signum(dy);
        int height = start.getHeight();
        int nextX = start.getX();
        int nextY = start.getY();
        int currentX = nextX;
        int currentY = nextY;
 
        while (true) {
            if (dx == 0) {
                nextY += ySignum;
            } else if (dy == 0) {
                nextX += xSignum;
            } else if (nextX != end.getX()) {
                int pointSlope = (nextX + xSignum - start.getX()) * dy / dx + start.getY();
 
                if (Math.abs(pointSlope - currentY) > 1) {
                    nextY += ySignum;
                } else {
                    nextX += xSignum;
                    nextY = pointSlope;
                }
            }
 
            Position current = new Position(currentX, currentY, height);
            Position next = new Position(nextX, nextY, height);
 
            if (projectile && !projectileCheck(current, next)) {
                return false;
            }
 
            if (!projectile && !traversable(current, next, size)) {
                return false;
            }
 
            if (nextX == end.getX() && nextY == end.getY()) {
                break;
            }
 
            currentX = nextX;
            currentY = nextY;
        }
        return true;
    }
 
}