bump.lib cannot get filters working

[JohnnyC]

I apologize for making so many threads the last few days.

I have actual collision working but if I put a filter it just all reads as nil so nothing collides. Trying to figure out what I'm doing wrong.

Code: Select all

local playerFilter = function(player, other)
	if other.enemy then return 'bounce'
	elseif other.ispbullet then return 'bounce'
	end
  -- else return nil
end

function movePlayer(player, dt,dir)
	if dir == 'right' then
		local goalX, goalY = player.x + player.speed * dt, player.y
		local actualX, actualY, cols, len = world:move(player, goalX, goalY, playerFilter)
		player.x, player.y = actualX, actualY
		-- deal with the collisions
		for i=1,len do
			if other.ispbullet then
			collided = true
			else
			end
		end
	end

My bullets are

Code: Select all

table.insert(pbullets, pbullet)
world:add(pbullet, pbullet.x, pbullet.y, pbullet.sx, pbullet.sy)

I'm aware that I only have the code when moving right but I just want to test it first. Thank you in advance for anyone who checked my thread out.

[veethree]

You're creating "playerFilter" in main.lua as a local variable, This means it's in the local scope of main.lua, So player.lua doesn't have access to it. Either make playerFilter a global, Or move it into player.lua.

There's a post on the löve blog about how scope works in lua, You can check it out here.

[JohnnyC]

I have a player filter in player.lua. I actually didn't know I had it in main as well. It was probably when I was trying to get it to work. However deleting the one in main and even making the one in player.lua global it still doesn't seem to be working.

Thank you for the link though since I've always been kinda bad with scope and I need to comb through my code and fix a lot of things regarding that.

[veethree]

"other.enemy" is a reference to the "enemy" object (table) that you add into the bump world (in enemyCreate), The object (table) you add into the bump world doesn't contain the "enemy" you check for in the playerFilter.

Adding the line "enemy.enemy = true" in "enemyCreate" should fix this. And bullets as far as i can tell aren't added to the bump world at all.

Also regarding scope, At the top of player.lua (same for enemy, bullets, pattern etc.) you put "Player = {}", And you return it at the bottom, But you never put anything into the table. So when you do "local Player = require "Player"" in main.lua, The variable "Player" in main.lua is just an empty table. This is pretty pointless.

What you should do is put all the functions and all player related variables into the Player table. So player.lua would look something like this

Code: Select all

local player = {}

function player.information()
	player.x = 0
	player.y = 0
	--etc
end

function player.update(dt)
	--update stuff
end

function player.draw()
	--draw stuff
end

return player

[JohnnyC]

pbullet is added under movement under love.keyboard.isDown('m'). I know it's a bit hidden, I apologize. I tried what you said and it still did not resolve the issue. The filter is still not working, if I remove the reference to the filter it works fine with the default slide. I just can't get the filter to work. Which is what I've been doing the last few hours or so. I've created a new project just to test it out and even in the brand new project I cannot get the filter working.

[veethree]

Here's a simple example of a filter working, The player can move through the orange block, but not the blue one.

Code: Select all

function love.load()
	bump = require "bump"
	world = bump.newWorld()

	player = {
		type = "player",
		x = love.graphics.getWidth() / 2 - 16,
		y = love.graphics.getHeight() / 2 - 16,
		size = 32
	}

	solidWall = {
		type = "solidWall",
		x = 32, 
		y = 128,
		width = 32,
		height = 32
	}

	notSolidWall = {
		type = "notSolidWall",
		x = love.graphics.getWidth() - 64, 
		y = 128,
		width = 32,
		height = 32
	}

	world:add(player, player.x, player.y, player.size, player.size)
	world:add(solidWall, solidWall.x, solidWall.y, solidWall.height, solidWall.width)
	world:add(notSolidWall, notSolidWall.x, notSolidWall.y, notSolidWall.height, notSolidWall.width)

end

function playerFilter(item, other)
	if other.type == "solidWall" then
		return "slide"
	elseif other.type == "notSolidWall" then
		return "cross"
	end
end

function love.update(dt)
	local goalX, goalY = player.x, player.y
	if love.keyboard.isDown("d") then
		goalX = player.x + 200 * dt
	elseif love.keyboard.isDown("a") then
		goalX = player.x - 200 * dt
	end

	if love.keyboard.isDown("s") then
		goalY = player.y + 200 * dt
	elseif love.keyboard.isDown("w")  then
		goalY = player.y - 200 * dt
	end

	local actualX, actualY, cols = world:move(player, goalX, goalY, playerFilter)

	player.x = actualX
	player.y = actualY
end

function love.draw()
	love.graphics.setColor(255, 255, 255)
	love.graphics.rectangle("fill", player.x, player.y, player.size, player.size)

	love.graphics.setColor(0, 125, 255)
	love.graphics.rectangle("fill", solidWall.x, solidWall.y, solidWall.width, solidWall.height)

	love.graphics.setColor(255, 125, 0)
	love.graphics.rectangle("fill", notSolidWall.x, notSolidWall.y, notSolidWall.width, notSolidWall.height)
end

function love.keypressed(key)
	if key == "escape" then love.event.push("quit") end
end

I'm pretty sure the problem is your filter is checking for a value that doesn't exist, so it always returns nil. Perhaps you can read over my code and figure things out.

[JohnnyC]

Thank you, the example code you made was very useful. I got it working, you actually explained it properly earlier but I just didn't understand it properly.

I had other.isenemy because that is how it is in the example on github. I was preoccupied with the 'is' thinking it was important to have, like the code is supposed to be other.is<type>. So even though I put enemy.enemy like you said I should. It didn't work because it was looking for isenemy not enemy.