module LaserSpot (RowAddr, ColAddr, CameraBank, MonitorBank, PixelData, BrightRow, BrightCol, clk, LaserPoint) ;

//
// Input
//
input [7:0] RowAddr ;		//Current row address being sent to memory
input [7:0] ColAddr ;		//Current column address being sent to memory
input [1:0] CameraBank ;	//Current Memory Bank the Camera is writing to
input [1:0] MonitorBank ;	//Current Memory Bank the Monitor is reading from
input [7:0] PixelData ;		//Current data being written to memory
input clk ;


//
// Output
//
output [7:0] BrightRow ;	//Brightest row corresponding to the current MonitorBank
output [7:0] BrightCol ;	//Brightest column corresponding to the current MonitorBank
output LaserPoint ;			//Is a laser point detected in this image frame



//
// Registered outputs and local variables
//
reg [7:0] BrightRow ;		//reg output
reg [7:0] BrightCol ;		//reg output
reg LaserPoint ;				//reg output

reg [7:0] BrightData ;		//The current brightest pixel data for the current frame being written to memory

reg [7:0] Row0 ;				//Local data that stores the row with the brightest pixel for Memory bank 0
reg [7:0] Row1 ;				//Same as above for MemoryBank 1
reg [7:0] Row2 ;				//Same as above for MemoryBank 2
reg [7:0] Row3 ;				//Same as above for MemoryBank 3

reg [7:0] Col0 ;				//Local data that stores the column with the brightest pixel for Memory bank 0
reg [7:0] Col1 ;				//Same as above for MemoryBank 1
reg [7:0] Col2 ;				//Same as above for MemoryBank 2
reg [7:0] Col3 ;				//Same as above for MemoryBank 3

reg Laser0 ;					//Local data that stores if a laser point was detected in Memory Bank 0
reg Laser1 ;					//Same as above for MemoryBank 1
reg Laser2 ;					//Same as above for MemoryBank 2
reg Laser3 ;					//Same as above for MemoryBank 3




//
// Control logic to determine the brightest spot in the frame
// being written to memory by the camera. It also determines
// if the brightest spot seen so far is bright enough to be
// the laser pointer (the pixel data must be > 253).
//
always @ (posedge clk)
  begin

	if ( (RowAddr == 0) && (ColAddr == 0) )	
		//We're at the beginning of a frame, so reset the BrightData counter
		BrightData <= 0;

		case (CameraBank) //Which memory bank is the camera writing to?
			2'b00: 	//Camera Bank 0
			  begin	 
				  	if (PixelData > BrightData)	//We've found a new brightest pixel
				  	  begin
					  		Row0 <= RowAddr;				//Save the row address
					  		Col0 <= ColAddr;				//Save the column address
					  		BrightData <= PixelData;	//Save the pixel data
					  		
					  		if ( (PixelData > 253) && (ColAddr < 200) )
					  			//If the pixel data is bright enough to be the laser pointer (>253)
					  			Laser0 = 1;
					  		else	//This pixel can't be the laser pointer because it isn't bright enough
					  			Laser0 = 0;
				  	  end
			  end
			  
			2'b01: 	 //Camera Bank 1-- Do the same procedure above for CameraBank 0
			  begin		    
				  	if (PixelData > BrightData)	//We've found a new brightest pixel
				  	  begin
					  		Row1 <= RowAddr;
					  		Col1 <= ColAddr;
					  		BrightData <= PixelData;
					  		if ( (PixelData > 253) && (ColAddr < 200) )
					  			Laser1 = 1;
					  		else
					  			Laser1 = 0;
				  	  end
			  end
			2'b10:  	//Camera Bank 2-- Do the same procedure above for CameraBank 0
			  begin			  
				  	if (PixelData > BrightData)	//We've found a new brightest pixel
				  	  begin
					  		Row2 <= RowAddr;
					  		Col2 <= ColAddr;
					  		BrightData <= PixelData;
					  		if ( (PixelData > 253) && (ColAddr < 200) )
					  			Laser2 = 1;
					  		else
					  			Laser2 = 0;
				  	  end
			  end
			2'b11: 	 //Camera Bank 3-- Do the same procedure above for CameraBank 0
			  begin		  
				  	if (PixelData > BrightData)	//We've found a new brightest pixel
				  	  begin
					  		Row3 <= RowAddr;
					  		Col3 <= ColAddr;
					  		BrightData <= PixelData;
					  		if ( (PixelData > 253) && (ColAddr < 200) )
					  			Laser3 = 1;
					  		else
					  			Laser3 = 0;
				  	  end
			  end
			//default: ; //Nothing goes here because we should always fall into 1 of the 4 cases above
		endcase
  end //end always
  
  
  
  
//
// Control logic to determine which row, column, and laser point 
// variable to send to the CrossHairs block. The row and column 
// will be used by the CrossHairs block to write the crosshairs 
// on the screen IF there is a laser point in the image.
//
always @ (posedge clk)
  begin
	case (MonitorBank) //Which memory bank is the monitor currently reading from?
		2'b00:	//Monitor Bank 0
		  begin
		  		BrightRow = Row0;			//Output the correct row information for this frame
		  		BrightCol = Col0;			//Output the correct column information for this frame
		  		LaserPoint = Laser0;		//Output if there is a laser spot in this frame
		  end
		  
		2'b01:	//Monitor Bank 1-- Do the same procedure above for MonitorBank 0
		  begin
		  		BrightRow = Row1;
		  		BrightCol = Col1;
		  		LaserPoint = Laser1;
		  end
		  
		2'b10: 	//Monitor Bank 2-- Do the same procedure above for MonitorBank 0
		  begin
		  		BrightRow = Row2;
		  		BrightCol = Col2;
		  		LaserPoint = Laser2;
		  end
		  
		2'b11:	//Monitor Bank 3-- Do the same procedure above for MonitorBank 0
		  begin
		  		BrightRow = Row3;
		  		BrightCol = Col3;
			  	LaserPoint = Laser3;
		  end
		//default: ; //Nothing goes here because we should always fall into 1 of the 4 cases above		
	endcase  
  end  //end always
  
endmodule