mirror of
https://github.com/irmen/prog8.git
synced 2024-08-28 13:28:56 +00:00
55 lines
1.3 KiB
Lua
55 lines
1.3 KiB
Lua
%import textio
|
|
%import floats
|
|
%zeropage basicsafe
|
|
|
|
main {
|
|
const uword width = 256
|
|
const uword height = 240
|
|
const ubyte max_iter = 16 ; 32 actually looks pretty nice but takes longer
|
|
|
|
sub start() {
|
|
void cx16.screen_mode($80, false)
|
|
cx16.r0=0
|
|
cx16.FB_init()
|
|
mandel()
|
|
}
|
|
|
|
sub mandel() {
|
|
const float XL=-2.200
|
|
const float XU=0.800
|
|
const float YL=-1.300
|
|
const float YU=1.300
|
|
float dx = (XU-XL)/width
|
|
float dy = (YU-YL)/height
|
|
ubyte pixelx
|
|
ubyte pixely
|
|
|
|
for pixely in 0 to height-1 {
|
|
float yy = YL+dy*(pixely as float)
|
|
|
|
cx16.FB_cursor_position(0, pixely)
|
|
|
|
for pixelx in 0 to width-1 {
|
|
float xx = XL+dx*(pixelx as float)
|
|
|
|
float xsquared = 0.0
|
|
float ysquared = 0.0
|
|
float x = 0.0
|
|
float y = 0.0
|
|
ubyte iter = 0
|
|
|
|
while xsquared+ysquared<4.0 {
|
|
y = x*y*2.0 + yy
|
|
x = xsquared - ysquared + xx
|
|
xsquared = x*x
|
|
ysquared = y*y
|
|
iter++
|
|
if iter>16
|
|
break
|
|
}
|
|
cx16.FB_set_pixel(iter)
|
|
}
|
|
}
|
|
}
|
|
}
|