collision help

[newcoder]

i keep getting errors and i know its probably something small so could someone just check my code so that i can get done with the collision. (im terrible at collision).
heres my code:

Code: Select all

System.usbDiskModeActivate() 

red = Color.new(225,0,0)
player = Image.load("player.png")
background = Image.load("background.png")
pic1 = Image.load("pic1.png")
pic2 = Image.load("pic2.png")
Pic = { }
Pic[1] = { x= 80, y = 95, height = pic1:height(), width = pic1:width() }
Player = { }
Player[1] = { x = 50, y = 107 } 
screenwidth = 480 - player:width()
screenheight = 272 - player:width()
playerHeight = 90
playerWidth = 90
function collisionCheck(Pic)
if &#40;Player&#91;1&#93;.x + playerWidth > Pic&#91;1&#93;.x&#41; and &#40;Player&#91;1&#93;.x < Pic&#91;1&#93;.x + Pic&#91;1&#93;.width&#41; and &#40;Player&#91;1&#93;.y + playerHeight > Pic&#91;1&#93;.y&#41; and &#40;Player&#91;1&#93;.y < Pic&#91;1&#93;.y + Pic&#91;1&#93;.height&#41; then
Player&#91;1&#93;.x = oldx
Player&#91;1&#93;.y = oldy
end 
end
function movePlayer&#40;&#41;
pad = Controls.read&#40;&#41;
if pad&#58;left&#40;&#41; then 
Player&#91;1&#93;.x = Player&#91;1&#93;.x - 1 
end
if pad&#58;right&#40;&#41; then 
Player&#91;1&#93;.x = Player&#91;1&#93;.x + 1 
end
if pad&#58;up&#40;&#41; then 
Player&#91;1&#93;.y = Player&#91;1&#93;.y - 1 
end
if pad&#58;down&#40;&#41; then 
Player&#91;1&#93;.y = Player&#91;1&#93;.y + 1 
end
end
while true do
pad = Controls.read&#40;&#41;
oldx = Player&#91;1&#93;.x
oldy = Player&#91;1&#93;.y
screen&#58;clear&#40;&#41;
collisionCheck&#40;Pic&#91;1&#93;&#41;
screen&#58;blit&#40;0,0,background&#41;
screen&#58;blit&#40;Pic&#91;1&#93;.x,Pic1.y,pic1&#41;
screen&#58;blit&#40;140,107,pic2&#41;
screen&#58;blit&#40;Player&#91;1&#93;.x,Player&#91;1&#93;.y,player&#41;
if pad&#58;left&#40;&#41; and Player&#91;1&#93;.x > 0 then
Player&#91;1&#93;.x = Player&#91;1&#93;.x - 2
end

if pad&#58;right&#40;&#41; and Player&#91;1&#93;.x < screenwidth then
Player&#91;1&#93;.x = Player&#91;1&#93;.x + 2
end

if pad&#58;up&#40;&#41; and Player&#91;1&#93;.y > 0 then
Player&#91;1&#93;.y = Player&#91;1&#93;.y - 2
end

if pad&#58;down&#40;&#41; and Player&#91;1&#93;.y < screenheight then
Player&#91;1&#93;.y = Player&#91;1&#93;.y + 2
end
screen.waitVblankStart&#40;&#41;
screen.flip&#40;&#41;
end

everything worked up until i implemented collision so i know its something with that.
i you want to know the actual error it says:
attempt to index global field '?' a nil value

[Altair]

What line is the error on?

[newcoder]

i think 15

[newcoder]

anyone??

[harleyg]

1. "i think 15" is not a definite answer.
2. Learn to wait on these forums, do not expect answer straight away.

[newcoder]

i know its just everytime i get to collision i end up dropping the project cause i cant get it to work. ill be more patient

[Altair]

Nope it cant be 15. Just run the game and see what the error says, complete with line number and post it here. Maybe then we can help you

[newcoder]

the error says this:
error: script.lua:15: attempt to index field '?' (a nil value)

[Altair]

And this is all of your code? That would mean it would be this line:

Code: Select all

playerWidth = 90 

Right?

I don't see anything wrong with that.

[Kleptoone]

You're passing the specific index into the function and trying to index it again. you pass Pic[1] and then are trying to test Pic[1][1]. just pass the array without the one and it should work (at least compile)