Tuto Gideros Game Template1 Part 7 Game

The Game Scene

This is going to be the last scene for our Gideros Game Template1 tutorial. A quick and simple one because you may decide to organize your game differently.

Note: we will code the player actor in the next chapter

Usually, when I make games and prototypes, I put all my levels in one scene. When I change levels I reload the Game scene with a variable indicating the current level, eg.: currlevel = 1, 2, ... and load the appropriate assets (graphics, sounds, ...).

I have been using this kind of architecture for quite some time, instead of calling my game scenes Level1, Level2, ..., I decided to call it: LevelX.

The Game scene (LevelX) will mainly consist of:

• a pause variable
• moving the mouse cursor out of the way :-)
• arranging our graphics into layers: background, actors, foreground, ...
• a game loop

It makes sense to create the file in the scenes folder. You can call the file levelX.lua, and the code:

LevelX = Core.class(Sprite)

local ispaused = false

function LevelX:init()
	-- move the cursor out of the way
	if not application:isPlayerMode() then
		local sw, sh = application:get("screenSize") -- the user's screen size!
		application:set("cursorPosition", sw, sh) -- 0, 0
	end
	-- layer sprites
	local mainlayer = Sprite.new() -- one Sprite to hold them all
	local bglayer = Sprite.new() -- background layer
	local bgfxlayer = Sprite.new() -- background fx layer
	local actorslayer = Sprite.new() -- actors layer
	local fgfxlayer = Sprite.new() -- foreground fx layer
	local fglayer = Sprite.new() -- foreground layer
	-- current level assets
	local bggfx, fggfx
	if g_currlevel == 1 then
		bggfx = Pixel.new(math.random(0xffffff), 1, myappwidth, myappheight)
		fggfx = Pixel.new(math.random(0xffffff), 1, myappwidth, myappheight/8)
	elseif g_currlevel == 2 then
		bggfx = Pixel.new(math.random(0xffffff), 1, myappwidth, myappheight)
	elseif g_currlevel == 3 then
		bggfx = Pixel.new(math.random(0xffffff), 1, myappwidth, myappheight)
		fggfx = Pixel.new(math.random(0xffffff), 1, myappwidth, myappheight/16)
	end
	-- the player1
	self.player1 = Player1.new()
	-- position
	if bggfx then bggfx:setPosition(0+myappleft, 0+myapptop) end
	if fggfx then fggfx:setPosition(0+myappleft, myappheight+myapptop-fggfx:getHeight()) end
	self.player1.x = myappwidth/2+myappleft
	self.player1.y = myappheight/2+myapptop
	self.player1:setPosition(self.player1.x, self.player1.y)
	-- add children to corresponding layer
	if bggfx then bglayer:addChild(bggfx) end -- add the background graphics to the background layer if any
	if fggfx then fglayer:addChild(fggfx) end -- add the foreground graphics to the foreground layer if any
	actorslayer:addChild(self.player1)
	-- order
	mainlayer:addChild(bglayer) -- first the background layer
	mainlayer:addChild(bgfxlayer) -- then the background fx layer
	mainlayer:addChild(actorslayer) -- then the actors layer
	mainlayer:addChild(fgfxlayer) -- then the foreground fx layer
	mainlayer:addChild(fglayer) -- lastely the foreground layer
	-- the main sprite
	self:addChild(mainlayer) -- the only Sprite layer that needs to be added to to scene tree hierarchy!
	-- the game loop
	self:addEventListener(Event.ENTER_FRAME, self.onEnterFrame, self)
	-- let's go
	self:myKeysPressed()
end

-- game loop
local dt
function LevelX:onEnterFrame(e)
	if not ispaused then
		dt = e.deltaTime
		if self.player1.isleft and not self.player1.isright and self.player1.x > 0 then -- LEFT
			self.player1.vx = -self.player1.speed*dt
			self.player1.flip = -1
		elseif self.player1.isright and not self.player1.isleft and self.player1.x < myappwidth then -- RIGHT
			self.player1.vx = self.player1.speed*dt
			self.player1.flip = 1
		else -- IDLE
			self.player1.vx = 0
		end
		if self.player1.isup and not self.player1.isdown and self.player1.y > 0 then -- UP
			self.player1.vy = -self.player1.speed*dt
		elseif self.player1.isdown and not self.player1.isup and self.player1.y < myappheight then -- DOWN
			self.player1.vy = self.player1.speed*dt
		else
			self.player1.vy = 0
		end
		-- actions
		if self.player1.isactionpunch1 then
			self.player1.vx *= 0.5*dt -- you choose, magik XXX
			self.player1.vy *= 0.5*dt -- you choose, magik XXX
		elseif self.player1.isactionpunch2 then
			self.player1.vx *= 0.25*dt -- you choose, magik XXX
			self.player1.vy *= 0.25*dt -- you choose, magik XXX
		elseif self.player1.isactionpunch3 then
			self.player1.vx *= 0.1*dt -- you choose, magik XXX
			self.player1.vy *= 0.1*dt -- you choose, magik XXX
		end
		-- move and flip
		self.player1.x += self.player1.vx
		self.player1.y += self.player1.vy
		self.player1:setPosition(self.player1.x, self.player1.y)
		self.player1.sprite:setScale(self.player1.sx * self.player1.flip, self.player1.sy)
	end
end

-- keys handler
function LevelX:myKeysPressed()
	self:addEventListener(Event.KEY_DOWN, function(e) -- KEY_UP
		if e.keyCode == KeyCode.ESC or e.keyCode == KeyCode.BACK then self:gotoScene() end -- MENU
		if e.keyCode == KeyCode.P then ispaused = not ispaused print("is paused: "..tostring(ispaused)) end -- PAUSE
		-- modifier
		local modifier = application:getKeyboardModifiers()
		local alt = (modifier & KeyCode.MODIFIER_ALT) > 0
		if (not alt and e.keyCode == KeyCode.ENTER) then -- nothing here!
		elseif alt and e.keyCode == KeyCode.ENTER then -- SWITCH FULLSCREEN
			ismyappfullscreen = not ismyappfullscreen
			application:setFullScreen(ismyappfullscreen)
		end
	end)
end

-- scenes navigation
function LevelX:gotoScene()
	self:removeAllListeners()
	for i = stage:getNumChildren(), 1, -1 do
		stage:removeChildAt(i)
	end collectgarbage()
	stage:addChild(Transitions.new(Menu.new())) -- next scene
end

Code comments

We start by defining a ispaused to pause the game using the letter P on the keyboard.

init

We move the mouse cursor out of the way. Done!

The main layer is the Parent of all the other layers, this way you could use the mainlayer Sprite as a camera, a viewport, ...:

• mainlayer Sprite Parent
  • bglayer Sprite Child
  • bgfxlayer Sprite Child
  • actorslayer Sprite Child
  • fgfxlayer Sprite Child
  • fglayer Sprite Child

The graphics for our game are put in their corresponding layer as children of that layer.

Finally we choose the order to display the layers. Here the first layer to be drawn is the background layer and all the other layers will be drawn on top:

• bglayer (drawn first)
• bgfxlayer
• actorslayer
• fgfxlayer
• fglayer (drawn last, on top of all the others)

the game loop

If the game is not in Pause mode it will execute what's inside it.

keys handler

We listen to any key press and switch the state of the game, go back to the Menu scene, ...

Next?

Well, to test that everything works fine, we add a player :-)

Prev.: Tuto Gideros Game Template1 Part 6 Options
Next: Tuto Gideros Game Template1 Part 8 Player

Tutorial - Gideros Game Template1

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