ヅラッシュ！ by NI-Lab.

基準となる座標値から時計回り(上,右,下,左)にぐるぐると座標値を求めてみる。

画像化には class AutoResizeVisualizer を利用。

ソースコード

import java.awt.geom.*;
import java.util.*;
 
// ぐるぐると外に広がっていく点の座標を求める
public class Grgr {
 
  public static void main(String[] args) throws Exception {
    Point2D[] p = getGuruGuruPoints();
    AutoResizeVisualizer arv = new AutoResizeVisualizer();
    for (int i = 0; i < p.length - 1; i++) {
      System.out.println(p[i]);
      arv.add(new Line2D.Double(p[i], p[i + 1]));
    }
    arv.visualize(300, 300, "grgr.png");
  }
 
  private static Point2D[] getGuruGuruPoints() {
 
    // user' s params
    final int num = 12;
    final double beginx = 0.0;
    final double beginy = 0.0;
    final double movex  = 10.0;
    final double movey  = 5.0;
 
    // directions
    final int NORTH = 0;
    final int EAST  = 1;
    final int SOUTH = 2;
    final int WEST  = 3;
 
    // vars
    ArrayList<Point2D> list = new ArrayList<Point2D>();
    double x = beginx;
    double y = beginy;
    list.add(new Point2D.Double(x, y));
 
    // clockwise
    for (int i = 0; i < num; i++) {
      
      // forward_num = {1,1,2,2,3,3,4,4,5,5,...}
      final int forward_num = (i / 2) + 1;
      
      // forward
      for (int j = 0; j < forward_num; j++) {
        switch (i % 4) {
          case NORTH :
            y -= movey;
            break;
          case EAST :
            x += movex;
            break;
          case SOUTH :
            y += movey;
            break;
          case WEST :
            x -= movex;
            break;
        }
        list.add(new Point2D.Double(x, y));
      }
    }
 
    return list.toArray(new Point2D[list.size()]);
  }
}

出力結果

画像:

標準出力:

Point2D.Double[0.0, 0.0]
Point2D.Double[0.0, -5.0]
Point2D.Double[10.0, -5.0]
Point2D.Double[10.0, 0.0]
Point2D.Double[10.0, 5.0]
Point2D.Double[0.0, 5.0]
Point2D.Double[-10.0, 5.0]
Point2D.Double[-10.0, 0.0]
Point2D.Double[-10.0, -5.0]
Point2D.Double[-10.0, -10.0]
Point2D.Double[0.0, -10.0]
Point2D.Double[10.0, -10.0]
Point2D.Double[20.0, -10.0]
Point2D.Double[20.0, -5.0]
Point2D.Double[20.0, 0.0]
Point2D.Double[20.0, 5.0]
Point2D.Double[20.0, 10.0]
Point2D.Double[10.0, 10.0]
Point2D.Double[0.0, 10.0]
Point2D.Double[-10.0, 10.0]
Point2D.Double[-20.0, 10.0]
Point2D.Double[-20.0, 5.0]
Point2D.Double[-20.0, 0.0]
Point2D.Double[-20.0, -5.0]
Point2D.Double[-20.0, -10.0]
Point2D.Double[-20.0, -15.0]
Point2D.Double[-10.0, -15.0]
Point2D.Double[0.0, -15.0]
Point2D.Double[10.0, -15.0]
Point2D.Double[20.0, -15.0]
Point2D.Double[30.0, -15.0]
Point2D.Double[30.0, -10.0]
Point2D.Double[30.0, -5.0]
Point2D.Double[30.0, 0.0]
Point2D.Double[30.0, 5.0]
Point2D.Double[30.0, 10.0]
Point2D.Double[30.0, 15.0]
Point2D.Double[20.0, 15.0]
Point2D.Double[10.0, 15.0]
Point2D.Double[0.0, 15.0]
Point2D.Double[-10.0, 15.0]
Point2D.Double[-20.0, 15.0]