/* PixelDrawing.java by Craig Persiko
   Demonstrates drawing with a 2-dimensional array of integers
*/

class PixelDrawing
{
  public static void main(String[] args)
  {
    int[][] pixels = new int[20][20];
    int[] headerRow = new int[20];

    // store the column numbers in the header row (used to label output)
    for(int c=0; c < headerRow.length; c++)
      headerRow[c] = c;

    clearScreen(pixels);

    for(int i=0; i<pixels.length; i++)
    {
      pixels[i][i] = 1; // put 1's in a line from top left to bottom right
      pixels[i][pixels.length-1-i] = 2; // put 2's in a line from top right to bottom left
    }

    // display a header row:
    System.out.print("Col# :\t");
    outputRow(headerRow);
    // display each row of the array
    for(int r=0; r < pixels.length; r++)
    {
      System.out.print("\nRow " + r + ":\t");
      outputRow(pixels[r]);
    }
    System.out.println();
  }

  // make every element of the 2-D array store 0.
  static void clearScreen(int[][] p)
  {
    int x, y;

    for (y=0; y < p.length; y++)
    {
      for (x=0; x < p[y].length; x++)
        p[y][x] = 0;
    }
  }

  // display all "size" elements of the 1-D array p.
  static void outputRow(int[] p)
  {
    int x;

    for (x=0; x < p.length; x++)
      if(p[x] < 9) System.out.print(p[x] + " ");
      else System.out.print(p[x]);
  }
}

/* Output:

[cpersiko@fog cs111a]$ java PixelDrawing
Col# :	0 1 2 3 4 5 6 7 8 910111213141516171819
Row 0:	1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 
Row 1:	0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 
Row 2:	0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 
Row 3:	0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 
Row 4:	0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 
Row 5:	0 0 0 0 0 1 0 0 0 0 0 0 0 0 2 0 0 0 0 0 
Row 6:	0 0 0 0 0 0 1 0 0 0 0 0 0 2 0 0 0 0 0 0 
Row 7:	0 0 0 0 0 0 0 1 0 0 0 0 2 0 0 0 0 0 0 0 
Row 8:	0 0 0 0 0 0 0 0 1 0 0 2 0 0 0 0 0 0 0 0 
Row 9:	0 0 0 0 0 0 0 0 0 1 2 0 0 0 0 0 0 0 0 0 
Row 10:	0 0 0 0 0 0 0 0 0 2 1 0 0 0 0 0 0 0 0 0 
Row 11:	0 0 0 0 0 0 0 0 2 0 0 1 0 0 0 0 0 0 0 0 
Row 12:	0 0 0 0 0 0 0 2 0 0 0 0 1 0 0 0 0 0 0 0 
Row 13:	0 0 0 0 0 0 2 0 0 0 0 0 0 1 0 0 0 0 0 0 
Row 14:	0 0 0 0 0 2 0 0 0 0 0 0 0 0 1 0 0 0 0 0 
Row 15:	0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 
Row 16:	0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 
Row 17:	0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 
Row 18:	0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 
Row 19:	2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 
[cpersiko@fog cs111a]$ 

*/