float gridWidth;
float gridHeight;

// Grid

public class Grid {
  int rows, cols;
  boolean[][] filled;
  ArrayList myCars = new ArrayList(); 
  
// --------------------------------------------------------- constructor
  
  public Grid(int rows, int cols) {
    this.rows = rows;
    this.cols = cols;
    filled = new boolean[rows][cols];
    clearGrid();
  }
  
// --------------------------------------------------------- emptyGrid
  
  public void emptyGrid() {
    
    clearGrid();
    
    myCars.clear();
      
  }
  
// --------------------------------------------------------- clearGrid
  
  public void clearGrid() {
    
    for (int i = 0; i < filled.length;i++) {
      for (int j = 0; j < filled[i].length;j++) {
        filled[i][j] = false;
      }
    }
      
  }  
  
// --------------------------------------------------------- updateCarsOnGrid
  
  public void updateCarsOnGrid() {
    
    clearGrid();
    
    // Check if there are any cars in arraylist
    if (!(myCars.isEmpty())) {

      for (int i = 0; i < myCars.size(); i++) {

        if (DEBUG) println("CURRENT CAR " + myCars.get(i));
        
        Vehicle tempCar = (Vehicle) myCars.get(i);

        int ver = 0;
        int hor = 0;

        switch(tempCar.direction) {
          case(carUP):
            ver = -1;
            break;
          case(carRIGHT):
            hor = 1;
            break;
          case(carDOWN):
            ver = 1;
            break;
          case(carLEFT):
            hor = -1;
            break;
        }
        
        for (int j = 0; j < tempCar.Length; j++)
        {
          filled[tempCar.xOriginPoint + hor*j][tempCar.yOriginPoint + ver*j] = true;
        }
      }
     
    }
    
  }
  
// --------------------------------------------------------- drawGrid
  
  public void drawGrid() {
    
    //float gridWidth = width/(float)filled.length;
    //float gridHeight = height/(float)filled[0].length;
    
    // Draw the grid
    
    for (int i = 0; i < filled.length;i++) {
      for (int j = 0; j < filled[i].length;j++) {

        //if (DEBUG) println("i " + i + " j " + j + "\n");
        
        if (DEBUG) { 
          if( filled[i][j]) {
            fill(0);
          } else {
            noFill();
          }
        }
        stroke(0);
        noFill();
        rect(i * gridWidth, j * gridHeight, gridWidth, gridHeight);
      }
    }
    
    // Draw Cars
    
    if (!(myCars.isEmpty())) {

      for (int i = 0; i < myCars.size(); i++) {

        //print(myCars.get(i));
        Vehicle tempCar = (Vehicle) myCars.get(i);
        
        
        
        stroke(tempCar.myColor);
        fill(tempCar.myColor);
        
        switch(tempCar.direction)
        {
          case(carUP):
            rect((tempCar.xOriginPoint * gridWidth)+1, ((tempCar.yOriginPoint-tempCar.Length+1) * gridHeight)+1, gridWidth-2, (gridHeight * tempCar.Length)-2);
            break;
          case(carRIGHT):
            rect((tempCar.xOriginPoint * gridWidth)+1, (tempCar.yOriginPoint * gridHeight)+1, (gridWidth * tempCar.Length)-2, gridHeight-2);
            break;
          case(carDOWN):
            rect((tempCar.xOriginPoint * gridWidth)+1, (tempCar.yOriginPoint * gridHeight)+1, gridWidth-2, (gridHeight * tempCar.Length)-2);
            break;
          case(carLEFT):
            rect(((tempCar.xOriginPoint-tempCar.Length+1) * gridWidth)+1, (tempCar.yOriginPoint * gridHeight)+1, (gridWidth * tempCar.Length)-2, gridHeight-2);
            break;  
        }
        
        stroke(0);
        if (selectedCar == tempCar) 
        {
          fill(0);
        } else 
        {
          noFill();
        }
        ellipseMode(CENTER);
        ellipse((tempCar.xOriginPoint * gridWidth)+gridWidth/2, (tempCar.yOriginPoint * gridHeight)+gridHeight/2, 20, 20);
      }
      
    }
    
  }

// --------------------------------------------------------- addVehicle
  
  public boolean addVehicle(Vehicle newVehicle) {
    if (newVehicle.legalPosition(this)) 
    {
      myCars.add(newVehicle);
      if (DEBUG) println("Car Placed on Grid");
      updateCarsOnGrid();
      return true;
    }
    if (DEBUG) println("Car NOT Placed on Grid");
    return false;
  }

// --------------------------------------------------------- removeVehicle
  
  public boolean removeVehicle(Vehicle newVehicle) {
    if (myCars.contains(newVehicle)) 
    {
      myCars.remove((myCars.indexOf(newVehicle))); 
      updateCarsOnGrid();
      return true;
    }
    return false;
  }

// --------------------------------------------------------- toString

  public String toString() {
    String discription = "";
    
    for (int i = 0; i < filled.length;i++) {
      for (int j = 0; j < filled[i].length;j++) {
        if (filled[j][i])
        { 
          discription += "X ";
        } else {
          discription += "O ";
        }
      }
      discription += "\n";
    }
    
    return discription;
  }
  
  
}