Allow pausing and frame-by-frame via key presses

main.lua

@@ -33,6 +33,9 @@ end
 function love.load(arg)
   game.window_width, game.window_height = love.graphics.getDimensions()
 
+  game.paused = false
+  game.frame_by_frame = false
+
   game.bubble_diameter = 60
   game.bubble_radius = game.bubble_diameter / 2
   game.bubble_speed = 900 -- px/s
@@ -121,10 +124,16 @@ function love.load(arg)
 end
 
 function love.update(dt)
+  if game.paused then return end
   if game.next_bubble.velocity_x ~= 0 or game.next_bubble.velocity_y ~= 0 then
     game.next_bubble.x = game.next_bubble.x + game.next_bubble.velocity_x * dt
     game.next_bubble.y = game.next_bubble.y + game.next_bubble.velocity_y * dt
   end
+
+  if game.frame_by_frame then
+    game.paused = true
+    game.frame_by_frame = false
+  end
 end
 
 function love.draw()
@@ -213,5 +222,10 @@ end
 function love.keypressed(key, scan_code, is_repeat)
   if key == 'escape' then
     love.event.quit()
+  elseif key == 'space' then
+    game.paused = not game.paused
+  elseif key == 'n' and game.paused then
+    game.frame_by_frame = true
+    game.paused = false
   end
 end