issue
i'm trying out some object oriented programming but i've run into some confusion
when i make a value in a list derived from another list
class={
new=function(self,tbl)
tbl=tbl or {}
setmetatable(tbl,{
__index=self
})
return tbl
end,
}
entity=class:new({
--dsp is read by the main upd
--stands for despawn
--removes the entity from the
--list if true
--dsp=false,
--dspwait=false,
x=0,
y='smelly',
--o is for origin
ox=0,
oy=0,
sprn=1,
--s is for size
--the size of the spr that is
xs=1,
ys=1,
--a is for animation
asprnum=2,
--asp is how much to divide
--the tmr by
--so 1 is every frame,
--2 is evey other frame,
--3 is every third frame,
--etc.
aspd=1,
--update=function()
--if x< camera.x+8 or x> camera.x+128 then
--if
--dsp = true
--end
--end,
draw=function()
spr(sprn,x,y)
print(y)
end,
}) |
and then try to reference a value from that same table from a function (as seen in the draw function
in the entity class) it spits out nil. i have the entire cart up above as you likely have already seen, ignore that it's trying to draw a sprite at a position thats text. i set y to smelly for testing so i could easily see if it was spitting out smelly or it was spitting out nil.
wait you can paste pico-8 sprites in here
|
[8x8] |
sprn is nil because you're not actually referencing a value from the table, you're referencing the global variable sprn which does not exist. You'd want to use self.sprn instead, and set the draw function like draw = function(self). Then, instead of calling thing.draw(), call it with a colon instead of a dot: thing:draw(). This is equivalent to calling thing.draw(thing), but it's neater.
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