// Based on Listing 5.1, Generative Art
float xstart, xnoise, ystart, ynoise, tnoise;
float x_end1, y_end1;
float x_end2, y_end2;

int num = 1;
Walker[] walkers = new Walker[num];

float magnitude;
float angle;
float noise_speed;

int width = 500;
int height= 500;
int cache_len = width * height;

float[] temp_xy;
float[][] mag_angle_list = new float[250000][2];
int j,k;

void setup() {
  size(500, 500);
  background(255);
  xstart = random(10);
  ystart = random(10);
  frameRate(25);

  textSize(30);

  for (int i = 0; i < num; i++){
    walkers[i] = new Walker(i);
  }

}

void draw() {
  background(255);
  // println(frameRate);
  // xstart += 0.01;
  // ystart += 0.01;

  ynoise = ystart;

  j = 0;
  for (int y = 1; y <= height; y+=1) {
    ynoise += 0.01;
    xnoise = xstart;
    for (int x = 1; x <= width; x+=1) {
      xnoise += 0.01;
      angle = noise(xnoise, ynoise, tnoise) * 3.14 * 2;

      x_end1 = (1 * cos(angle)) + x;
      y_end1 = (1 * sin(angle)) + y;

      mag_angle_list[j][0] = x_end1;
      mag_angle_list[j][1] = y_end1;

      j = j + 1;
    }
  }


  for (int i = 0; i < num; i++){
    temp_xy = walkers[i].getLocation();
    // lookup mechanism
    int idx = (int)(((temp_xy[1] - 1) * width) + temp_xy[0]);
    float next_x = mag_angle_list[idx][0];
    float next_y = mag_angle_list[idx][1];
    walkers[i].update(next_x,next_y);

    print(next_x);
  }
}


class Walker {
  // fields
  String s;
  float x, y, a;
  float tx, ty, ta;
  color c;

  // constructor
  Walker(int i) {
    s = nf(i);
    x = random(width);
    y = random(height);
    tx = random(1000);
    ty = random(1000);
    ta = random(1000);
    c = color(2,2,2);
    // c = color(random(255),random(255),random(255));
  }

  float[] getLocation(){
    return new float[]{x,y};
  }

  // method
  void update(float next_x, float next_y) {
    pushMatrix();
    translate(x, y);
    rotate(a);
    fill(c, 100);
    text(s, 0, 0);
    popMatrix();

    tx += 0.01;
    ty += 0.01;
    ta += 0.001;

    x += next_x;
    y += next_y;
    a += 0.1-0.05;

    if (x<0)
      x += width;
    else if (x>width)
      x -= width;
    if (y<0)
      y += height;
    else if (y>height)
      y -= height;
  }
}