add character movement acceleration/deceleration

right_coin.lua

@@ -159,18 +159,44 @@ do -- Player
 		isFlipped=false
 	}
 	
+	local maxSp=2
+	local accel=0.3
+	local decel=0.5
+  
 	function Player:direct()
 		if btn(2) then 
-			self.vx = -2
+			self:goLeft()
-			self.isFlipped = true
 		elseif btn(3) then
-			self.vx = 2
+			self:goRight()
-			self.isFlipped = false
+		else self:stop()
-		else self.vx = 0
 		end
 		if btnp(4) and self.vy == 0 then self.vy = j end
 	end
 	
+	function Player:goLeft()
+		if self.vx > 0 then self.vx=0 end
+		self.vx=self.vx - accel
+		if self.vx < -maxSp then self.vx=-maxSp end
+		self.isFlipped = true
+	end
+	
+	function Player:goRight()
+		if self.vx < 0 then self.vx=0 end
+		self.vx=self.vx + accel
+		if self.vx > maxSp then self.vx=maxSp end
+		self.isFlipped = false
+	end
+	
+	function Player:stop()
+		if self.vx < 0 then 
+			self.vx= self.vx + decel
+			if self.vx > 0 then self.vx=0 end
+		elseif self.vx > 0 then 
+			self.vx= self.vx - decel
+			if self.vx < 0 then self.vx=0 end
+		end
+	end
+  
 	function Player:update()
 		self:resolve()
 		self.x = self.x + self.vx