prog8/examples/mandelbrot.p8

47 lines
1.3 KiB
Lua

%import c64lib
%import c64utils
%import c64flt
~ main {
const uword width = 30
const uword height = 20
const ubyte max_iter = 16
sub start() {
c64scr.print("calculating mandelbrot fractal...\n")
c64.TIME_HI=0
c64.TIME_MID=0
c64.TIME_LO=0
for ubyte pixely in 0 to height-1 {
float yy = (pixely as float)/0.4/height - 1.0
for ubyte pixelx in 0 to width-1 {
float xx = (pixelx as float)/0.3/width - 2.2
float xsquared = 0.0
float ysquared = 0.0
float x = 0.0
float y = 0.0
ubyte iter = 0
while (iter<max_iter and xsquared+ysquared<4.0) {
y = x*y*2.0 + yy
x = xsquared - ysquared + xx
xsquared = x*x
ysquared = y*y
iter++
}
c64scr.setcc(pixelx+4, pixely+1, 160, max_iter-iter)
}
}
float duration = floor(((c64.TIME_LO as float) + 256.0*(c64.TIME_MID as float) + 65536.0*(c64.TIME_HI as float))/60.0)
c64.PLOT(0, 0, 21)
c64scr.print("finished in ")
c64flt.print_f(duration)
c64scr.print(" seconds!\n")
}
}