For this program, you will need to add use the files found in example 2.

• Add a command to read in a file of commands. The format should be:

   
      read filename
  

• Add a command to draw a circle, given the center and the radius. The format should be:

      circle x y r
  

• Add a command to draw a n sided polygon. The format should be:

      polygon n x_1 y_1 x_2 y_2 ... x_n y_n
  

  Where n represents the number of end points and x_k,y_k is endpoint k.

• Add a command to draw a filled n sided polygon. The format should be:

      filledpolygon n x_1 y_1 x_2 y_2 ... x_n y_n
  

  Where n represents the number of end points and x_k,y_k is endpoint k.

• Implement the scan line polygon fill algorithm using the Nonzero winding rule.

• Add a fill command with the format:

      fill x y c
  

  which fills an area 4 connected to x,y with color c. Any 4-connected area to x,y with the same original color should be filled. It is an error to fill an area with it's current color. Assume 1 = white and 0 = black.

• Add a command to clear the screen. The format should be:

     clear c
  

  where c represents the color to clear the screen to. Assume 1 = white and 0 = black.