mike: Rewrote paddle col detection; removed comments; less reliance on global variables

love/mike/lib/functions.lua

@@ -12,6 +12,9 @@ function screen_col_detect(object, display)
   return true
 end
 
+
+
+
 function create_object(start_x, start_y, width, height, speed)
   local	object = {}
 	object.x = start_x
@@ -29,7 +32,36 @@ function num_is_pos(number)
 	end
 end
 
-function ball_bounce(ball)
+
+-- Inspired by https://love2d.org/wiki/BoundingBox.lua
+-- Returns true if boxes overlap
+
+function hitbox_collision(x1, y1, width1, height1,
+                          x2, y2, width2, height2)
+	return x1 < x2 + width2 and
+  	     x2 < x1 + width1 and
+    	   y1 < y2 + height2 and
+      	 y2 < y1 + height1
+end
+
+
+--Takes a string "left" or "right"
+function bounce(str, ball)
+	if str == "right" and
+		 not num_is_pos(ball.x_speed) then
+		 ball.x_speed = ball.x_speed *-1
+
+	elseif
+		str == "left" and
+		num_is_pos(ball.x_speed) then
+		ball.x_speed = ball.x_speed *-1
+	end
+	return ball
+end
+
+
+
+function ball_bounce(player, ball)
 	local paddle_hit = false
 	ball.x = ball.x + ball.x_speed
 	ball.y = ball.y + ball.y_speed
@@ -45,25 +77,27 @@ function ball_bounce(ball)
 	end
 
 	--If ball hits paddle 
-	if ball.y + 1 >= player.y and
+	
-		 ball.x >= player.x and
+	if hitbox_collision(ball.x, ball.y, ball.width, ball.height,
-		 ball.x <= player.x + player.width then
+											player.x, player.y, player.width, player.height) then
-		 ball.y_speed = ball.y_speed *-1
-		 paddle_hit = true
-	 end
 
-	 if paddle_hit == true then
+		
-		 if ball.x < player.x + (player.width/2) and
+		-- We don't need to check left limits because we already know
-			 num_is_pos(ball.x_speed) then
+		-- there was a collision, so just bounce left if the ball is
-			 ball.x_speed = ball.x_speed *-1
+		-- left of center on the paddle
-		 elseif ball.x > player.x + (player.width/2) and
+		if ball.x < player.x + (player.width /2) then
-			 not num_is_pos(ball.x_speed) then
+			bounce("left", ball)
-			 ball.x_speed = ball.x_speed *-1
+		
-		 end
+		-- If the ball is on the right side, bounce right
-	 end
+		elseif ball.x > player.x +(player.width /2) then
+			bounce("right", ball)
+		end
 
+		-- We don't really need to worry about the center
+		-- so we won't modify it.
+
+		-- Bounce
+		ball.y_speed = ball.y_speed *-1
+	end
 	return ball
 end
-
-
-	

love/mike/lib/keys.lua

@@ -33,7 +33,7 @@ function half_speed(object_speed)
 	end
 end
 
-function check_keys(object) 
+function check_keys(object, screen) 
   local newObject = {}
   newObject.x = object.x
   newObject.y = object.y
@@ -49,14 +49,6 @@ function check_keys(object)
 		newObject.x = newObject.x - half_speed(newObject.speed)
 	end
 
---  if love.keyboard.isDown("up") then
---		newObject.y = newObject.y - newObject.speed
---	end
-
---	if love.keyboard.isDown("down") then
---		newObject.y = newObject.y + newObject.speed
---	end
-	
 	if screen_col_detect(newObject, screen) then
 		return newObject
 	else
@@ -64,3 +56,5 @@ function check_keys(object)
 	end
 end
 
+--Inspired by https://love2d.org/wiki/BoundingBox.lua
+--Returns true if boxes overlap

love/mike/main.lua

@@ -10,18 +10,18 @@ function love.load()
 	screen.height = love.graphics.getHeight()
 	
 	-- Create a table to hold all the player data
-	player = create_object(screen.width /2, screen.height - 50, 25, 5, 10)
+	player = create_object(screen.width /2, screen.height - 50, 30, 5, 10)
 	-- Create a table to hold ball data
 	ball = create_object(screen.width /2, screen.height /2, 1, 1, 10)
-	ball.x_speed = ball.speed /2
+	ball.x_speed = (ball.speed /2)
-	ball.y_speed = ball.speed /2
+	ball.y_speed = (ball.speed /2)
 
 
 end
 
 function love.update(dt)
-	player = check_keys(player)
+	player = check_keys(player, screen)
-	ball = ball_bounce(ball)
+	ball = ball_bounce(player, ball)
 end
 
 function love.draw()