Syntax + Runtime errors in Zine #1 particle code

Wed, 27 Apr 2016 05:55:37 UTC

Hi. Going through the Smoke Particle section of zine #1 and found an error I couldn't solve. If you copy paste the following code..

function   make_smoke(x,y,init_size,col)
 local s = {}
 s.x=x
 s.y=y
 s.col=col
 s.width = init_size
 s.width_final = init_size + rnd(3)+1
 s.t=0
 s.max_t = 30+rnd(10)
 s.dx = (rnd(.8).4)
 s.dy = rnd(.05)
 s.ddy = .02
 add(smoke,s)
 return s
end
function   _init()
 smoke = {}
 cursorx = 50
 cursory = 50
 color = 7
end

function   move_smoke(sp)
if (sp.t > sp.max_t) then
 del(smoke,sp)
end
if (sp.t > sp.max_t15) then
 sp.width +=1
 sp.width = min(sp.width,sp.width_final)
end
sp.x = sp.x + sp.dx
sp.y = sp.y + sp.dy
sp.dy= sp.dy+ sp.ddy
sp.t = sp.t + 1
end
function  _update ()
foreach(smoke, move_smoke)
if btn(0,0) then cursorx=1 end
if btn(1,0) then cursorx+=1 end
if btn(2,0) then cursory-=1 end
if btn(3,0) then cursory+=1 end
if btn(4,0) then color = flr(rand(16)) end
make_smoke(cursorx,cursory,rnd(4),color)
end

function  draw_smoke(s)
circfill(s.x, s.y,s.width, s.col)
end
function _draw()
cls()
foreach(smoke, draw_smoke)
end

.. you get 'syntax error line 10. ')' expected near '.4'. I changed the line to

 s.dx = (rnd(.8))*.4

which seems to have fixed the problem, but then you get 'line 27: attempt to compare nil with number. in _f line 27. in _update line 37'

Anyone know a fix?

The cartridge that the tutorial points to at the end seems broken as well (https://www.lexaloffle.com/bbs/?tid=1920)

Edit: if you replace 'sp.max_t15' with a number it works ok.

Syntax errors in zine 3 collision code

Sat, 23 Apr 2016 17:12:22 UTC

Hi. I'm trying to learn about collisions using the DOM8VERSE section of zine 3 but I'm getting weird error messages whenever I try and use a foreach.

For example, when I try this:

function _update()
if btnp(5, 0) then
add(objects, bulletconstruct(player1.position.x,player1.position.y))
end

foreach(objects, function(obj)
obj.update(obj)
end

end

.. I get ')' expected ( to close '(' at line 0.0003891 near 'end'

I've tried adding and taking away brackets, as well as 'end' statements but I can't get it to work. Thought it was strange as I'm copy pasting zine 3 code.

Anyone know the solution?

elayekay [Lexaloffle Blog Feed]

Syntax + Runtime errors in Zine #1 particle code

Syntax errors in zine 3 collision code