prog8/examples/mandelbrot.p8
Irmen de Jong de06353194 auto select correct library to import based on target, instead of having c64- and cx16- prefix variants
some programs are now 100% source compatible between C64 and Cx16 targets!
import libraries have been rena;med
2020-09-21 00:50:09 +02:00

55 lines
1.4 KiB
Lua

%import syslib
%import textio
%import floats
%zeropage basicsafe
; TODO use RDTIM() to get the time and make this system agnostic
main {
const uword width = 30
const uword height = 20
const ubyte max_iter = 16
sub start() {
txt.print("calculating mandelbrot fractal...")
c64.TIME_HI=0
c64.TIME_MID=0
c64.TIME_LO=0
ubyte pixelx
ubyte pixely
for pixely in 0 to height-1 {
float yy = (pixely as float)/0.4/height - 1.0
for 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++
}
txt.setcc(pixelx+4, pixely+1, 160, max_iter-iter)
}
}
float duration = ((c64.TIME_LO as float)
+ 256.0*(c64.TIME_MID as float)
+ 65536.0*(c64.TIME_HI as float))/60.0
txt.plot(0, 21)
txt.print("finished in ")
floats.print_f(duration)
txt.print(" seconds!\n")
}
}