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I want to make my own raycaster game in picotron and I have been following this blog written for a pico-8 raycaster. I get an error when I run this and I am not sure what I should do to fix this issue. Help would be much appreciated.

Other than the code, all I did is make a sprite in slot 1 and draw a simple map in the map editor.

 
function _init()
	cam={
		x=12,
		y=12,
		a=0,
		w2d=2
	}
	scrx=0
end

function _update()
	controls()
end

function _draw()
	cls()
	map(0,0,0,0,16,16)
	circ(cam.x,cam.y,2,12)
	--for scrx=0,480 do
	--	raycast(cam,scrx)
	--end
	raycast(cam,240)
end

function controls()
	if btn(0) then
		cam.a+=0.01
	end
	if btn(1) then
		cam.a-=0.01
	end
	if btn(2) then
		cam.x+=cos(cam.a)*0.5
		cam.y+=sin(cam.a)*0.5
	end
	if btn(3) then
		cam.x+=cos(cam.a)*-0.25
		cam.y*=sin(cam.a)*-0.25
	end
end

function raycast(cam,scrx)
	local rayvx,rayvy=
		cam.vx-cam.vy*cam.w2d*(scrx-64)/128,
		cam.vy+cam.vx*cam.w2d*(scrx-64)/128

	-- distance traveled
	local dist=0
	-- current coordinates
	local x,y=cam.x,cam.y
	-- map cel coordinate and value
	local celx,cely=x8,y8
	local cel=mget(celx,cely)
	-- direction of ray
	local dirx,diry=
		sgn(rayvx),sgn(rayvy)

	-- distances across map cel
	local dist4x,dist4y=
		abs(8/rayvx),
		abs(8/rayvy)

	-- distances to next map cel
	local dx,dy=
		abs(4+4*dirx-x%8),
		abs(4+4*diry-y%8)
	local dist2x,dist2y=
		abs(dx/rayvx),
		abs(dy/rayvy)

	-- which direction / angle
	-- the wall was hit from
	local hita=0

	-- perform dda
	repeat

		if dist2x=64
end



What error are you getting?

I'm not home right now but I remember the error being about a missing "then" by the if statement at the end of the code. I'm not sure how that part of the code is supposed to work anyways

Ah yes...
That bit at the end looks very broken
Looks like the code's been cut off in that guide - a repeat statement should have an until part too. You might need to find another guide?

I suppose so. I sent an email to the author to see if they still have the code to share
1

If you view source on that webpage the full code is there. Here's the rest of it.

 
-- perform dda
repeat
   if dist2x < dist2y then
      celx+=dirx
      dist+=dist2x
      dist2y-=dist2x
      dist2x=dist4x
      hita=0.25-dirx*0.25
   else
      cely+=diry
      dist+=dist2y
      dist2x-=dist2y
      dist2y=dist4y
      hita=0.5+diry*0.25
   end

   local cel=mget(celx,cely)
   if fget(cel,0) then
      -- ray hit a wall
      rect(celx*8,cely*8,celx*8+7,cely*8+7,12)
   else
      rect(celx*8+2,cely*8+2,celx*8+5,cely*8+5,11)
   end

until dist >= 64

Oddly enough when I copied the code over here it got cut off in the same way as on the author's page. The problem was that they hadn't put a space between < and dist2y. So everything after dist2x until =64 was being interpreted as an html tag that the browser didn't know how to render.

If you encounter more broken code @Nedim, just open up the page source and look for the code there. And if you feel like it pass that info along to the author in case they feel like fixing it.
1

Ohhhhh that actually makes a lot of sense. Thank you so much



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