Camera Shake and Global Pause Effects

game_pause_and_cam_shake.lua

-- Created for my Ko-fi article about my game
-- dev journey with my retro platformer
-- https://ko-fi.com/post/ENGHUN-Unnamed-Project--Making-Abilites-Look-B-X8X2DH3X2

-- Code is In progress, heavily not optimized
-- and geared towards readability until PICO_8
-- token counts come into play

-- Update Cycle for the game, notice that we
-- do not update core gameplay things if we 
-- have pause time set up in pickups
-- see: https://gist.github.com/Achie72/b528c49987b2550d37c9d45a5ccbcaad
function update_game()
  
  -- Game pause effect is we have time remaining
	if not (global.pauseTime > time()) then
		control_player()
		update_fireballs()
		update_enemies()
		check_stomp()
		update_scores()
		update_pickup()
	end
	update_particles()
	if player.life <= 0 then
		-- set our state to endscreen
		global.state = 2
		global.endScreenMessage = endScreenMessages[flr(rnd(#endScreenMessages)+1)]
		global.transition = true
		global.trans.x = player.x-64
		global.trans.y = player.y-64
	end
  
  -- Check for camera shake
	if time() > global.camShakeTime then
		global.camShake = false
	end
end



-- camera shake code
function screen_shake(x, y)
  local fade = 0.95
  local offset_x=16-rnd(32)
  local offset_y=16-rnd(32)
  offset_x*=global.offset
  offset_y*=global.offset
  
  camera(x+offset_x,y+offset_y)
  global.offset*=fade
  if global.offset<0.05 then
    global.offset=0
  end
end

-- game draw code, took out what is not needed
-- for the camera setup, but this handels
-- basically drawing everything in the game as well
function draw_game()

	-- camera setup
	local target_pos = {
		x = player.x-60,
		y = 0
	}

	local camera_treshold = 16

	local position_minimum = {
		x = 0,
		y = 0
	}
	local position_maximum = {
		x = 128*8-64,
		y = 64+182
	}
	-- calculate out of buffer corrigations
	if (cam.x + camera_treshold) < target_pos.x then
		cam.x += min(target_pos.x - (cam.x + camera_treshold), 4)
	end
	if (cam.x - camera_treshold) > target_pos.x then
		cam.x += min(target_pos.x - (cam.x - camera_treshold), 4)
	end
	if (cam.y + camera_treshold) < target_pos.y then
		cam.y += min(target_pos.y - (cam.y + camera_treshold), 4)
	end
	if (cam.y - camera_treshold) > target_pos.y then
		cam.y += min(target_pos.y - (cam.y - camera_treshold), 4)
	end

	if cam.x < position_minimum.x then
		cam.x = position_minimum.x
	end
	if cam.x > position_maximum.x then
		cam.x = position_maximum.x 
	end
	if cam.y < position_minimum.y then
		cam.y = position_minimum.y
	end
	if cam.y > position_maximum.y then
		cam.y = position_maximum.y
	end

	if global.camShake then
		screen_shake(cam.x, cam.y)
	else
		camera(cam.x, cam.y)
	end

end