gridgrid.java

import java.util.ListIterator;

GridSpace[][] grid;
final int SIZE = 200;
ArrayList<GridSpace> points;

void setup() {
  size(1000, 1000);
  background(255);
  stroke(0,0,0);
  smooth();
  strokeCap(SQUARE);
  grid = new GridSpace[SIZE][SIZE];
  int xIndex = 0;
  for(int x = width / SIZE; x < width; x += (width / SIZE)) {
    int yIndex = 0;
    for(int y = height / SIZE; y < height; y += (height / SIZE)) {
      GridSpace space = new GridSpace(new PVector(x,y), xIndex, yIndex); 
      grid[xIndex][yIndex] = space;
      yIndex++; 
    }
    xIndex++;
  }
  
  points = new ArrayList<GridSpace>();
  
  this.initializeGrid();
}

void draw() {
  if(points.isEmpty()) {
    noLoop();
    saveFrame("gridStuff" + (int) random(36500) + ".png");
  }
  ListIterator<GridSpace> it = points.listIterator();
  while(it.hasNext()) {
    GridSpace space = it.next();
    GridSpace newSpace = findPlaceToMove(space);
    if(newSpace == null) {
      it.remove();
    }
    else {
      line(space.loc.x, space.loc.y, newSpace.loc.x, newSpace.loc.y);      
      space.loc.set(newSpace.loc.x, newSpace.loc.y, 0);
      space.xIndex = newSpace.xIndex;
      space.yIndex = newSpace.yIndex;
    }     
  }
}

public void initializeGrid() {
  for(int i = 0; i < 800; i++) {
    int x = (int) random(SIZE);
    int y = (int) random(SIZE);
    GridSpace space = grid[x][y];
    if(space != null) {
      PVector p = space.loc;
      points.add(new GridSpace(new PVector(p.x,p.y), x, y));
    }
  }  
}

public GridSpace findPlaceToMove(GridSpace space) {
  int x = space.xIndex;
  int y = space.yIndex;
  GridSpace newPoint = null;
  int[] searches = new int[8];
  for(int i = 0; i < 8; i++) {
    searches[i] = 0;
  }
  boolean found = false;
  while(!found) {
    boolean allChecked = true;
    for(int i = 0; i < 8; i++) {
      if(searches[i] == 0) {
        allChecked = false;
      }
    }
    if(allChecked) {
      return null;
    }  
    int rand = (int) random(8);
    if(searches[rand] == 1) {
      continue;
    }
    else {
      searches[rand] = 1;
      int newX = 0;
      int newY = 0;
      if(rand == 0) {
        newX = x - 1;
        newY = y - 1;
      }
      else if(rand == 1) {
        newX = x - 1;
        newY = y;
      }
      else if(rand == 2) {
        newX = x - 1;
        newY = y + 1;
      }
      else if(rand == 3) {
        newX = x;
        newY = y + 1;
      }
      else if(rand == 4) {
        newX = x + 1;
        newY = y + 1;
      }
      else if(rand == 5) {
        newX = x + 1;
        newY = y;
      }
      else if(rand == 6) {
        newX = x + 1;
        newY = y - 1;
      }
      else if(rand == 6) {
        newX = x + 1;
        newY = y - 1;
      }
      else if(rand == 7) {
        newX = x;
        newY = y - 1;
      }
      if((newX < 0 || newX > (SIZE - 1)) ||
        (newY < 0 || newY > (SIZE - 1))) {
        continue;    
      }
      GridSpace newSpace = grid[newX][newY];
      if(newSpace == null) {
        continue;
      }
      if(!newSpace.isFilled()) {
        newPoint = new GridSpace(new PVector(newSpace.loc.x, newSpace.loc.y), newX, newY);
        found = true;
        
        newSpace.setFilled(true);
      }
    }
  }
  
  return newPoint;
}
  

public class GridSpace
{
  
  public PVector loc;
  public int xIndex;
  public int yIndex;
  private boolean isFilled;
  
  public GridSpace(PVector loc, int xIndex, int yIndex) {
    this.loc = loc;
    this.xIndex = xIndex;
    this.yIndex = yIndex;
    isFilled = false;
  }
  
  public void setFilled(boolean filled) {
    isFilled = filled;
  }
  
  public boolean isFilled() {
    return isFilled;
  }
}