datapath.v

module datapath(xInput, yInput, loadDatapath, xOut, yOut, clk, resetLow, colorOut, oldOrCurrent, 
		finishedPrintingSignal, collisionHappened, points);
	input [7:0] xInput;
	input [6:0] yInput;
	input loadDatapath; //load enable signal
	input clk;
	input resetLow;
	input oldOrCurrent;
	output reg [7:0] points; //point tracking
	output reg [7:0] xOut; // x coord to vga facilitator
	output reg [6:0] yOut; // y coord to vga facilitator
	output reg [2:0] colorOut;
	output reg finishedPrintingSignal;
	output collisionHappened;
	reg [2:0] birdOrPipeOrCoin; //responsible for keeping track of whether bird calculation or pipe calculation in effect
								// i.e if counting pixels for bird, this is 0, if pipe 1, its 1 etc.
	
	reg [7:0] x;
	reg [6:0] y;
	reg [3:0] count;
	
	reg [7:0] xPipe1;
	reg [6:0] yPipe1;
	reg [7:0] xPipe2;
	reg [6:0] yPipe2;
	reg [7:0] xPipe3;
	reg [6:0] yPipe3;
	
	reg [4:0] countWidth;
	reg [7:0] countHeight;
	reg checkUpperPipeFinish; // check if upper part of pipe done

	reg [2:0] colorBird;
	reg [2:0] colorPipe;
	reg [2:0] colorPoint;
	
	/*wire*/reg [2:0] speed;
	initial speed = 3'd1;
	
	wire [7:0] height;
	wire [4:0] width;
	assign height = 8'd40; // height of the gap between pipe ends
	assign width = 5'd6; // width of pipe
	reg [4:0] pipeHeightIncrease;
	
	//crash checking
	
	wire collisionHappened1;
	wire collisionHappened2;
	wire collisionHappened3;
	wire collisionHappened4;
	
	/*	Our difficulty setting, at the moment the speed doubles after getting 5 points, 
		will probably make this higher later so that the game won't get too hard at an
		early stage*/
	always @(*)
	begin
		if (!resetLow)
		begin
			speed <= 3'd1;
		end
		else if (points >= 8'd20)
		begin
			speed <= 3'd3;
		end
		else if (points >= 8'd5)
		begin
			speed <= 3'd2;
		end
	end
	
	collisionPipe checkPipe1(
		/*Inputs*/
		.evaluateCollision(1'b1),
		.xBird(xInput), 
		.yBird(yInput), 
		.xPipe(xPipe1), 
		.yPipe(yPipe1), 
		.clk(clk),
		.resetLow(resetLow), 
		.height(height), 
		.width(width),
		
		/*Outputs*/
		.collisionHappen(collisionHappened1)
		);
			
	collisionPipe checkPipe2(
		/*Inputs*/
		.evaluateCollision(1'b1),
		.xBird(xInput),
		.yBird(yInput),
		.xPipe(xPipe2), 
		.yPipe(yPipe2), 
		.clk(clk),
		.resetLow(resetLow),
		.height(height), 
		.width(width),
		
		/*Outputs*/
		.collisionHappen(collisionHappened2)
		);
			
	collisionPipe checkPipe3(
		/*Inputs*/
		.evaluateCollision(1'b1),
		.xBird(xInput),
		.yBird(yInput),
		.xPipe(xPipe3), 
		.yPipe(yPipe3), 
		.clk(clk),
		.resetLow(resetLow), 
		.height(height),
		.width(width), 
		
		/*Outputs*/
		.collisionHappen(collisionHappened3)
		);
			
	collisionSurface checkSurface(
		/*Inputs*/
		.evaluateCollision(1'b1),
		.yBird(yInput),
		.resetLow(resetLow),
		.clk(clk),
		
		/*Outputs*/
		.crashHappen(collisionHappened_4)
		);
	
	/*	Marks that a collision has happened if either of the previous modules
		notes that a collision has happened on their end */
	assign collisionHappened = collisionHappened1 | collisionHappened2 | collisionHappened3 | collisionHappened4;

	always @(posedge clk)
	begin
		// Reset, low active
		if (resetLow == 1'b0)
		begin
			x <= 8'd78;
			y <= 7'd58;
			xOut <= 8'd0;
			yOut <= 7'd0;
			xPipe1 <= 8'd135;
			yPipe1 <= 7'd40;
			xPipe2 <= 8'd20;
			yPipe2 <= 7'd60;
			xPipe3 <= 8'd60;
			yPipe3 <= 7'd30;
			points <= 8'd0;
			countWidth <= 5'd0;
			countHeight <= 8'd0;
			checkUpperPipeFinish <= 1'd0;
			colorBird <= 3'd0;
			colorPipe <= 3'd0;
			count <= 4'd0; //for pixel counting
			finishedPrintingSignal <= 1'd0;
			colorOut <= 3'd0;
			
		end
		// Loading value for x and y, and set count to 0.
		else if (loadDatapath == 1'b1)
		begin
				x <= xInput;
				xOut <= xInput;
				y <= yInput;
				xOut <= yInput;
				count <= 4'b0000;
				finishedPrintingSignal <= 1'b0;
				birdOrPipeOrCoin = 1'b0;
				//+++++++++++PIPE UNO location++++++
				if (oldOrCurrent == 1'b1)
					if (xPipe1 - speed >= 8'd160) //boundary checking
					begin
						xPipe1 <= 8'd160/*8'd154*/;
						yPipe1 <= 7'd30 + pipeHeightIncrease; //might be able to remove this line, comment out and see what happens
					end
					else
					begin
						if (!collisionHappened) //no crash occured
						begin
							if (xPipe1 + width >= 8'd78 && xPipe1 + width - speed < 8'd78) //score increase criteria, once u are in middle position of screen regarding x 
								points <= points + 1;
							xPipe1 <= xPipe1 - speed; // decrease the x coordinate by 1 (pipes move left as bird moves right)
						end
						else
							xPipe1 <= xPipe1; // if collision happens stop movement
					end
				else
					xPipe1 <= xPipe1;
				//+++++++++++++++++PIPE DEUX location++++++++
				if (oldOrCurrent == 1'b1)
					if (xPipe2 - speed >= 8'd160)
					begin
						xPipe2 <= 8'd160;
						yPipe2 <= 7'd20 + pipeHeightIncrease;
					end
					else
					begin
						if (!collisionHappened)
						begin
							if (xPipe2 + width >= 8'd78 && xPipe2 + width - speed < 8'd78)
								points <= points + 1;
							xPipe2 <= xPipe2 - speed;
						end
						else
							xPipe2 <= xPipe2;
					end
				else
					xPipe2 <= xPipe2;

				//+++++++++++++PIPE TROIS location+++++++++++
				if (oldOrCurrent == 1'b1)
					if (xPipe3 - speed >= 8'd160)
					begin
						xPipe3 <= 8'd160;
						yPipe3 <= 7'd40 + pipeHeightIncrease;
					end
					else
					begin
						if (!collisionHappened)
						begin
							if (xPipe3 + width >= 8'd78 && xPipe3 + width - speed < 8'd78)
								points <= points + 1;
							xPipe3 <= xPipe3 - speed;
						end
						else
							xPipe3 <= xPipe3;
					end
				else
					xPipe3 <= xPipe3;
				
				xOut <= 8'd0; // for pixel counting
				yOut <= 7'd0; // for pixel counting
				countWidth <= 5'd0;
				countHeight <= 8'd0;
				finishedPrintingSignal <= 1'b0;
				checkUpperPipeFinish <= 1'b0;
				//if dealing with old position of visuals we want to print clear colors as to prepare for new position for visuals
				if (oldOrCurrent == 1'b0)
				begin
					colorBird <= 3'b000;
					colorPipe <= 3'b000;
					colorPoint <= 3'b000;
				end
				else
				begin // dealing with current so not the erasure state, we gonna apply relevant colors for new positions of visuals
					colorBird <= 3'b100;
					colorPipe <= 3'b010;
					colorPoint <= 3'b110;
				end
		end
		// !!! PRINTING STAGES FOR BIRD, PIPES, AND COINS !!!
		// BIRD PRINT (16 pixel count)
		else if (birdOrPipeOrCoin == 3'b0)
		begin
			colorOut <= colorBird;
			// counting.
			if (count != 4'b1111)
			begin
				xOut <= x + count[3:2];
				yOut <= y + count[1:0];
				count <= count + 1'b1;
			end
			// Stay on the lower right pixel.
			else
			begin
				xOut <= x + count[3:2];
				yOut <= y + count[1:0];
				birdOrPipeOrCoin = 3'd1;
			end
		end // bird print done ~~~~~~~
		// !!!!!!!!!!!PIPE 1 PRINT !!!!!!!!!
		else if (birdOrPipeOrCoin == 3'd1)
		begin
			colorOut <= colorPipe;
			if (!checkUpperPipeFinish)
			// Printing upper half of the pair of the pipes.
			begin
				if (countWidth != (width - 1) || yOut != 0) // Last px of the upper half.
				begin
					if (countWidth < width)
					begin // Printing one row.
						colorOut <= colorPipe;
							
						xOut <= xPipe1 + countWidth;
						countWidth <= countWidth + 1'b1;
						yOut <= yPipe1 - countHeight;
					end
					else
					begin // One row of the pxs have been printed.
						countWidth <= 0;
						countHeight <= countHeight + 1;
						xOut <= xPipe1;
						yOut <= yPipe1 - countHeight;
					end
				end
				else
				begin // Finished printing upper half.
					xOut <= xPipe1 + countWidth;
					countWidth <= 0;
					countHeight <= height;
					checkUpperPipeFinish <= 1'b1;
				end
			end
			// Stay on the lower right pixel.
			else
			// Printing lower half of the pair of the pipes.
			begin
				if (countWidth != (width - 1) || yOut != 119) // Last px of the upper half.
				begin
					if (countWidth < width)
					begin // Printing one row.
						xOut <= xPipe1 + countWidth;
						countWidth <= countWidth + 1'b1;
						yOut <= yPipe1 + countHeight;
					end
					else
					begin // One row of the pxs have been printed.
						countWidth <= 0;
						countHeight <= countHeight + 1;
						xOut <= xPipe1;
						yOut <= yPipe1 + countHeight;
					end
				end
				else
				begin // Finished printing lower half.
					xOut <= xPipe1 + countWidth;
					checkUpperPipeFinish <= 1'b0;
					countWidth <= 5'd0;
					countHeight <= 8'd0;
					count <= 4'b0000;
					if (xPipe1 >= 8'd82)
						birdOrPipeOrCoin <= 3'd4; // go to coin 1
					else
						birdOrPipeOrCoin <= 3'd2; // go to pipe 2
				end
			end
		end //pipe 1 print done ~~~~
		else if (birdOrPipeOrCoin == 3'd4)
		begin //!!!!!!!!!!!!!!!!COIN 1 PRINT!!!!!!!!!!!!!!!!!!!!!
			colorOut <= colorPoint;
			// counting.
			if (count != 4'b1111)
			begin
				xOut <= xPipe1 + count[3:2];
				yOut <= yPipe1 + 7'd19 + count[1:0];
				count <= count + 1'b1;
			end
			// Stay on the lower right pixel.
			else
			begin
				xOut <= xPipe1 + count[3:2];
				yOut <= yPipe1 + 7'd19 + count[1:0];
				birdOrPipeOrCoin <= 3'd2;
			end
		end //coin 1 print done ~~~~~
		// !!!!!!!!!!!!!!!!!!!!PIPE 2 PRINT!!!!!!!!!!!!!!!!!!!!!!!
		else if (birdOrPipeOrCoin == 3'd2)
		begin
			colorOut <= colorPipe;
			if (!checkUpperPipeFinish)
			// Printing upper half of the pair of the pipes.
			begin
				if (countWidth != (width - 1) || yOut != 0) // Last px of the upper half.
				begin
					if (countWidth < width)
					begin // Printing one row.
						colorOut <= colorPipe;

						xOut <= xPipe2 + countWidth;
						countWidth <= countWidth + 1'b1;
						yOut <= yPipe2 - countHeight;
					end
					else
					begin // One row of the pxs have been printed.
						countWidth <= 0;
						countHeight <= countHeight + 1;
						xOut <= xPipe2;
						yOut <= yPipe2 - countHeight;
					end
				end
				else
				begin // Finished printing upper half.
					xOut <= xPipe2 + countWidth;
					countWidth <= 0;
					countHeight <= height;
					checkUpperPipeFinish <= 1'b1;
				end
			end
			// Stay on the lower right pixel.
			else
			// Printing lower half of the pair of the pipes.
			begin
				if (countWidth != (width - 1) || yOut != 119) // Last px of the upper half.
				begin
					if (countWidth < width)
					begin // Printing one row.
						xOut <= xPipe2 + countWidth;
						countWidth <= countWidth + 1'b1;
						yOut <= yPipe2 + countHeight;
					end
					else
					begin // One row of the pxs have been printed.
						countWidth <= 0;
						countHeight <= countHeight + 1;
						xOut <= xPipe2;
						yOut <= yPipe2 + countHeight;
					end
				end
				else
				begin // Finished printing lower half.
					xOut <= xPipe2 + countWidth;	
					checkUpperPipeFinish <= 1'b0;
					countWidth <= 5'd0;
					countHeight <= 8'd0;
					count <= 4'b0000;
					if (xPipe2 >= 8'd82)
						birdOrPipeOrCoin <= 3'd5;
					else
						birdOrPipeOrCoin <= 3'd3;
				end
			end
		end// PIPE 2 PRINT DONE ~~~~~~~~~~~
		else if (birdOrPipeOrCoin == 3'd5)
		begin //!!!!!!!!!!!!!!!!!!!!!COIN 2 PRINT!!!!!!!!!!!!!!!!!!!!!!
			colorOut <= colorPoint;
			// counting.
			if (count != 4'b1111)
			begin
				xOut <= xPipe2 + count[3:2];
				yOut <= yPipe2 + 7'd19 + count[1:0];
				count <= count + 1'b1;
			end
			// Stay on the lower right pixel.
			else
			begin
				xOut <= xPipe2 + count[3:2];
				yOut <= yPipe2 + 7'd19 + count[1:0];
				birdOrPipeOrCoin <= 3'd3;
			end
		end// COIN 2 PRINT DONE ~~~~~~~~~~
		else if (birdOrPipeOrCoin == 3'd3)
		begin //!!!!!!!!!!!!!!!!!!!!PIPE 3 PRINT!!!!!!!!!!!!!!!!!!!!!!!!!
			colorOut <= colorPipe;
			if (!checkUpperPipeFinish)
			// Printing upper half of the pair of the pipes.
			begin
				if (countWidth != (width - 1) || yOut != 0) // Last px of the upper half.
				begin
					if (countWidth < width)
					begin // Printing one row.
						colorOut <= colorPipe;

						xOut <= xPipe3 + countWidth;
						countWidth <= countWidth + 1'b1;
						yOut <= yPipe3 - countHeight;
					end
					else
					begin // One row of the pxs have been printed.
						countWidth <= 0;
						countHeight <= countHeight + 1;
						xOut <= xPipe3;
						yOut <= yPipe3 - countHeight;
					end
				end
				else
				begin // Finished printing upper half.
					xOut <= xPipe3 + countWidth;
					countWidth <= 0;
					countHeight <= height;
					checkUpperPipeFinish <= 1'b1;
				end
			end
			// Stay on the lower right pixel.
			else
			// Printing lower half of the pair of the pipes.
			begin
				if (countWidth != (width - 1) || yOut != 119) // Last px of the upper half.
				begin
					if (countWidth < width)
					begin // Printing one row.
						xOut <= xPipe3 + countWidth;
						countWidth <= countWidth + 1'b1;
						yOut <= yPipe3 + countHeight;
					end
					else
					begin // One row of the pxs have been printed.
						countWidth <= 0;
						countHeight <= countHeight + 1;
						xOut <= xPipe3;
						yOut <= yPipe3 + countHeight;
					end
				end
				else
				begin // Finished printing lower half.
					xOut <= xPipe3 + countWidth;	
					checkUpperPipeFinish <= 1'b0;
					countWidth <= 5'd0;
					countHeight <= 8'd0;
					count <= 4'b0000;
					if (xPipe3 >= 8'd82)
						birdOrPipeOrCoin <= 3'd6;
					else
						finishedPrintingSignal = 1'b1;
				end
			end
		end // PIPE 3 DONE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		else if (birdOrPipeOrCoin == 3'd6)
		begin //!!!!!!!!!!!!!!!!!!!!!!!COIN 3 PRINT!!!!!!!!!!!!!!!!!!!!!!!!!!!
			colorOut <= colorPoint;
			// counting.
			if (count != 4'b1111)
			begin
				xOut <= xPipe3 + count[3:2];
				yOut <= yPipe3 + 7'd19 + count[1:0];
				count <= count + 1'b1;
			end
			// Stay on the lower right pixel.
			else
			begin
				xOut <= xPipe3 + count[3:2];
				yOut <= yPipe3 + 7'd19 + count[1:0];
				finishedPrintingSignal = 1'b1;
			end
		end // COIN 3 DONE ~~~~~~~~~~~~~~~
	end //end for always 
	
	
	// just needed for proper compilation, doesnt really have effect, kinda of like bandaid, needs re-evaluation
	
	always @(posedge clk)
	begin
		if (!resetLow)
			pipeHeightIncrease <= 5'd0;
		else
			pipeHeightIncrease <= pipeHeightIncrease + 5'd15;
	end


endmodule