Something like this?

[img]http://i.imgur.com/wX8WR.png[/img]


or:

[img]http://i.imgur.com/DFZJf.png[/img]

YES.

Thing is, I pretty much need to generate it row-by-row, or at most screen-by-screen, in such a way to keep down generation time [i]and[/i] memory use. (Yay phone capabilities.) Part of the problem is I've been coding straight to those requirements, rather than adapting something that works to them.

The algorithm I used is easy enough to do a row at a time as needed, but it does depend upon you having access to a basic Perlin noise fractal generator. Basically, this is what I did to generate the two previous images:

[code]
function pitBaseFunction(x,y)
if x<-0.5 or x>0.5 then return 1 else return 0 end
end

function pitFunction(x,y)
local turb=perlinFractal:get(x,y)
return pitBaseFunction(x+turb,y)
end

for x=0,255,1 do
for y=0,1023,1 do
local nx=x/255 * 4 - 2
local ny=y/1024 * 4
buf:set(x,y, pitFunction(nx,ny))
end
end

anl.saveDoubleArray("buf.tga", buf)
[/code]

[b]pitBaseFunction[/b] defines the basic cross-section of a single row of pit, by returning open (0) for any x in the range (-0.5,0.5) and returning solid (1) for anything beyond that range.

[b]pitFunction[/b] then calls a Perlin noise fractal with the input coordinates and uses the resulting value to perturb the x coordinate before calling [b]pitBaseFunction[/b]. The algorithm can be generated a cell at a time, a row at a time, a page at a time, however you need, and the generated pit is of basically infinite depth, although it will repeat if the Perlin function has a repeating period so if you want it to go a long way you'll need to construct your Perlin function to accommodate.

The character of the pit can be tweaked by tweaking the Perlin fractal frequency or by scaling the amplitude of the fractal output.