feat(scene): add *Start() and *End() functions.

Make the scene children able to add functions before or after 
everything.

examples/basic/test_scene2/init.lua

@@ -58,10 +58,13 @@ function TestScene:mousepressed(x, y)
 end
 
 
-function TestScene:draw()
+function TestScene:drawStart()
   love.graphics.setColor(.4, 0, 0, 1)
   love.graphics.rectangle("fill", 0, 0, 424, 240)
+  utils.graphics.resetColor()
+end
 
+function TestScene:drawEnd()
   love.graphics.setColor(1, 1, 1, 1)
   love.graphics.print(math.floor(self.i) .. " ; " .. self.mouse.x .. ":" .. self.mouse.y .. ":" .. self.world:countActors(), 16, 16)
 

gamecore/modules/scenes.lua

@@ -59,10 +59,18 @@ end
 -- UPDATE FUNCTIONS
 -- Handle stuff that happens every steps
 
+function Scene:updateStart(dt)
+
+end
+
 function Scene:update(dt)
   -- Empty function, is just here to avoid crash
 end
 
+function Scene:updateEnd(dt)
+
+end
+
 function Scene:updateWorld(dt)
   if (self.world ~= nil) and (self.world.isActive) then
     self.world:update(dt)
@@ -105,10 +113,18 @@ end
 -- DRAW FUNCTIONS
 -- Draw the scene and its content
 
+function Scene:drawStart()
+
+end
+
 function Scene:draw()
 
 end
 
+function Scene:drawEnd()
+
+end
+
 function Scene:drawWorld(dt)
   if (self.world ~= nil) then
     self.world:draw()

gamecore/scenemanager.lua

@@ -64,11 +64,13 @@ end
 
 function SceneManager:update(dt)
   if (self.currentScene ~= nil) then
+    self.currentScene:updateStart(dt)
     self.currentScene:setKeys()
     self.currentScene.assets:update(dt)
     self.currentScene.menusystem:update(dt)
     self.currentScene:updateWorld(dt)
     self.currentScene:update(dt)
+    self.currentScene:updateEnd(dt)
   end
 end
 
@@ -108,9 +110,11 @@ end
 function SceneManager:draw()
   self.controller.screen:apply()
   if (self.currentScene ~= nil) then
+    self.currentScene:drawStart()
     self.currentScene:drawWorld()
-    self.currentScene:draw(dt)
+    self.currentScene:draw()
     self.currentScene.menusystem:draw()
+    self.currentScene:drawEnd()
   end
   self.controller.screen:cease()
 end