module CrossHairs (clk, BrightRow, BrightCol, ReadData, vcnt, hcnt, PixelDataOut, LaserPoint);
		
//
// Input
//		
input clk ;
input [7:0] BrightRow ;	//Brightest pixel in the image is in this row
input [7:0] BrightCol ;	//Brightest pixel in the image is in this col
input [7:0] ReadData ;	//pixel data read from memory
input [7:0] vcnt ;		//pixel column read from memory
input [7:0] hcnt ;		//pixel row read from memory
input LaserPoint ;


//
// Output
//
output [7:0] PixelDataOut ;


//
// Output registers
//
reg [7:0] PixelDataOut ;


//
// Basically, this module determines if the current row and 
// column being read from memory has a laser point in it. If
// it does, then purple cross-hairs are displayed on the image,
// otherwise the purple cross-hairs are not displayed.
//
// Note that there is a one cycle delay from getting the data
// from memory and sending the address to memory. Thus, our
// row and column will be one pixel out of sync. This can be
// fixed at a later date.
//
always @ (posedge clk)
  begin
  		if (LaserPoint)	//There was a laser point detected in this image
  			begin
  				if ((BrightRow == vcnt ) || (BrightCol == hcnt ))  
  					// If the current row == the brightest row in the image, or the current
  					// column == the brightest column in the image, display the pixel as a
  					// purple pixel (this will create the cross hairs).
  					PixelDataOut = 255;
  				else
  					// Otherwise, pass the original pixel data read from memory to the
  					// VGA block. In there, if the pixel data is < 200, the display
  					// will print a black pixel to the screen instead. This is the
  					// way we implement color mapping. Any pixel below 200 is displayed
  					// as a black pixel.
  					if (ReadData > 250)
  						PixelDataOut = ReadData;
  					else
  						PixelDataOut = 0;
  			end
  		else
			// There is no laser point in the image, so don't display any
			// purple pixels (this removes the purple cross hairs from
			// being displayed in the image).
  			PixelDataOut = ReadData;
  
  end //end always

endmodule