Platformer game using Tiled , colission detection layer fail

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Oprogrammer
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Posts: 9
Joined: Sat Mar 01, 2014 10:37 pm

Platformer game using Tiled , colission detection layer fail

Post by Oprogrammer » Tue Mar 04, 2014 9:49 pm

Hey guys , i am using Tiled to create my tile map , i have two layers , Solid and Death , before when i had integrated Solid layer only my character would not slip through the tiles , but ever since i have "tried" to integrate the death layer my character just slips into the tiles,

This is the code i have for the collision detection part.

Code: Select all

function player:isColliding(map, x, y) -- character collides with tile layer solid only from tmx map. 
		local layer = map.tl["Solid"]
		local tileX, tileY = math.floor(x / map.tileWidth), math.floor(y / map.tileHeight)
		local tile = layer.tileData(tileX, tileY)
		local layer2 = map.tl["Death"]
		local tileX, tileY = math.floor(x / map.tileWidth), math.floor(y / map.tileHeight)
		local tile = layer2.tileData(tileX, tileY)
		return not(tile == nil)	
	end
	
and here is my player:collide (event)

Code: Select all

 function player:collide(event)
		if event == "floor" then
			self.y_vel = 0
			self.standing = true
		end
		if event == "ceiling" then
			self.y_vel = 0
		end
		
		if event == "death" then
			self.y_vel = 0
			player.x = 256
		end
	end
I assume there is something wrong in the player:collide function but i don't know what.

PS: i am using advance tiled loader, and looked at their range of in depth tutorials but could not even get the game to compile after the changes.

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Azhukar
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Posts: 478
Joined: Fri Oct 26, 2012 11:54 am

Re: Platformer game using Tiled , colission detection layer

Post by Azhukar » Tue Mar 04, 2014 9:58 pm

Try this:

Code: Select all

function player:isColliding(map, x, y) -- character collides with tile layer solid only from tmx map. 
	local tileX, tileY = math.floor(x / map.tileWidth), math.floor(y / map.tileHeight)
	local layer = map.tl["Solid"]
	local tile = layer.tileData(tileX, tileY)
	local layer2 = map.tl["Death"]
	local tile2 = layer2.tileData(tileX, tileY)
	return (tile~=nil or tile2~=nil)
end

Oprogrammer
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Posts: 9
Joined: Sat Mar 01, 2014 10:37 pm

Re: Platformer game using Tiled , colission detection layer

Post by Oprogrammer » Tue Mar 04, 2014 10:09 pm

Hello ,

Thank you for the quick reply !! , i have put your code it and i am glad to say that my character does not slip into the tiles :).

I wanted to ask, as the tile in the "Death" layer has a physical presence , how would i make a function that would go if player is colliding with tile layer "Death" then ....

Edit: I have added this to my player: update(dt) function

Code: Select all

function player:update(dt) -- update player position 
		local halfX = self.w / 2
		local halfY = self.h / 2
		
		self.y_vel = self.y_vel + (world.gravity * dt)
		
		self.x_vel = math.clamp(self.x_vel, -self.speed, self.speed)
		self.y_vel = math.clamp(self.y_vel, -self.flySpeed, self.flySpeed)
		
		local nextY = self.y + (self.y_vel*dt)
		if self.y_vel < 0 then
			if not (self:isColliding(map, self.x - halfX, nextY - halfY))
				and not (self:isColliding(map, self.x + halfX - 1, nextY - halfY)) then
				self.y = nextY
				self.standing = false
			else
				self.y = nextY + map.tileHeight - ((nextY - halfY) % map.tileHeight)
				self:collide("ceiling")
			end
		end
		if self.y_vel > 0 then
			if not (self:isColliding(map, self.x-halfX, nextY + halfY))
				and not(self:isColliding(map, self.x + halfX - 1, nextY + halfY)) then
					self.y = nextY
					self.standing = false
			else
				self.y = nextY - ((nextY + halfY) % map.tileHeight)
				self:collide("floor")
			end
			else self.y = nextY - ((nextY + halfY) % map.tileHeight)
				self:collide("death")
		end
		
		local nextX = self.x + (self.x_vel * dt)
		if self.x_vel > 0 then
			if not(self:isColliding(map, nextX + halfX, self.y - halfY))
				and not(self:isColliding(map, nextX + halfX, self.y + halfY - 1)) then
				self.x = nextX
			else
				self.x = nextX - ((nextX + halfX) % map.tileWidth) 
			end
		elseif self.x_vel < 0 then
			if not(self:isColliding(map, nextX - halfX, self.y - halfY))
				and not(self:isColliding(map, nextX - halfX, self.y + halfY - 1)) then
				self.x = nextX
			else
				self.x = nextX + map.tileWidth - ((nextX - halfX) % map.tileWidth)
			end
		end
		
		self.state = self:getState()
	end
The issue i have is it registers a "floor" as a "death" which makes my character re spawn to the start ( which it should in an event of a death) I know it is linked to the "if not (self:isColliding) " as i have put an else statement in saying if event is not floor then event = death .
Last edited by Oprogrammer on Wed Mar 05, 2014 12:04 am, edited 1 time in total.

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Azhukar
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Posts: 478
Joined: Fri Oct 26, 2012 11:54 am

Re: Platformer game using Tiled , colission detection layer

Post by Azhukar » Tue Mar 04, 2014 10:27 pm

Oprogrammer wrote:The issue i have is it registers a "floor" even as a "death"
You will have to return a value in player:isColliding that will indicate whether the collision was caused by one layer or the other. Then you can get this value in your update and react accordingly.

Oprogrammer
Prole
Posts: 9
Joined: Sat Mar 01, 2014 10:37 pm

Re: Platformer game using Tiled , colission detection layer

Post by Oprogrammer » Wed Mar 05, 2014 12:57 pm

Would i have to put an If else statement in the player:isColliding , that would say something like

Code: Select all

If tile then
     a=1
end

if tile2 then
a =2 
end

and then in the player:update(dt) i just put a statement that goes if a =1 then ......... else .........

PS: sorry i am new to lua and don't understand all the concepts.

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Azhukar
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Posts: 478
Joined: Fri Oct 26, 2012 11:54 am

Re: Platformer game using Tiled , colission detection layer

Post by Azhukar » Wed Mar 05, 2014 1:34 pm

Something similar.

Read about function return values here http://www.lua.org/pil/5.1.html

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