table index is nill

[babablackshep]

tried to add some rectangles to the world and this error appeared

[kikito]

I need more information in order to be able to help you. Can you provide of the code showing the issue?

[babablackshep]

sure thing:

local bump = require 'lib/bump'
require "var"

local world = bump.newWorld(50)

function love.update(dt)
if love.keyboard.isDown('d')then px = px + psped * dt end
if love.keyboard.isDown('a')then px = px - psped * dt end
if love.keyboard.isDown('s')then py = py + psped * dt end
if love.keyboard.isDown('w')then py = py - psped * dt end
if love.keyboard.isDown('escape')then love.quit() end
end

function love.draw()
love.graphics.setColor(255,255,255)
player = love.graphics.rectangle("fill", px,py,50,50)
enemy = love.graphics.rectangle("line",ex,ey,50,50)
end

world:add(player, px, py, 50, 50)
world:add(enemy, ex, ey, 50, 50)

print(world:getRect(enemy))

sorry for being a bit late
and if it helps the error is at line 600 in bump.lua(i probably should have said that to begin with)

[kikito]

Hi there,

The problem is, fortunatelly, quite simple: you are not using love.graphics.rectangle correctly.

In LÖVE, the drawing-related functions (like love.graphics.rectangle, or love.graphics.circle) don't "create" anything. They just "change the colors of the current canvas in a certain way" (when drawing a rectangle, they change the colors so they look like a rectangle. When drawing a circle, they change the colors to look like a circle, etc). But once they are done changing the colors they don't "store that". They don't "create a rectangle" or a circle. They return nothing (which in Lua is the same as returning nil).

For this reason, player and enemy are nil (nothing). When you try to add them to the world, there is an error, because you are "adding nothing".

A way to get around this is using a Lua table to represent player and enemy, and then using that table to both add it to the world and drawing it. In addition to that, you were not updating the world after moving the player, and the order in which you were doing initializations and checks was a bit ... too original.

Here is a version that should work (I have not tested it for typos and such).

local bump = require 'lib/bump'

local world = bump.newWorld(50)
local player = {x = 10, y = 10, w = 50, h = 50, speed = 100}
local enemy = {x = 100, y = 100, w = 50, h = 50}

world:add(player, player.x, player.y, player.w, player.h)
world:add(enemy, enemy.x, enemy.y, enemy.w, enemy.h)

function love.update(dt)
  if love.keyboard.isDown('d') then player.x = player.x + player.speed * dt end
  if love.keyboard.isDown('a') then player.x = player.x - player.speed * dt end
  if love.keyboard.isDown('s') then player.y = player.y + player.speed * dt end
  if love.keyboard.isDown('w') then player.y = player.y - player.speed * dt end

  world:move(player, player.x, player.y)

  if love.keyboard.isDown('escape') then love.quit() end

  print(world:getRect(enemy))
end

function love.draw()
  love.graphics.setColor(255,255,255)
  love.graphics.rectangle("fill", player.x, player.y, player.w, player.h)
  love.graphics.rectangle("fill", enemy.x, enemy.y, enemy.w, enemy.h)
end

Since this is not an issue with bump, I am closing this issue. Feel free to ask more questions (if you have questions about LÖVE, however, I would recommend you to ask them in the LÖVE forums, there's lots of people which can help you there besides me, and my schedule has been a bit packed lately).

Regards!