comparison: test_mandelbrot.lua
test_mandelbrot.lua
- changeset 4
- caf89bc9100a
- child 5
- fa4d448b07d3
equal
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| 3:7f619444bc2a | 4:caf89bc9100a |
|---|---|
| 1 -- Code originally by Luiz Henrique de Figueiredo | |
| 2 -- At http://lua-users.org/lists/lua-l/2010-10/msg00754.html | |
| 3 -- Ported to lua-xpm by Matthew Wild | |
| 4 | |
| 5 local xpm = require "xpm"; | |
| 6 | |
| 7 local N=255 | |
| 8 | |
| 9 local pic = xpm.new(N,N); | |
| 10 | |
| 11 for i=1,N do | |
| 12 local y=2-4*(i-1)/(N-1) | |
| 13 for j=1,N do | |
| 14 local x=-2+4*(j-1)/(N-1) | |
| 15 local xc,yc=x,y | |
| 16 local X,Y=0,0 | |
| 17 local p=0 | |
| 18 for n=1,255 do | |
| 19 X,Y = X^2-Y^2+xc, 2*X*Y+yc | |
| 20 if X^2+Y^2>4 then p=n break end | |
| 21 end | |
| 22 pic:setpixel(j, i, ("#%02x%02x%02x"):format(p,p,p)); | |
| 23 end | |
| 24 end | |
| 25 | |
| 26 pic:render(io.stdout); |
