prog8/examples/cx16/mandelbrot-gfx-colors.p8

89 lines
2.0 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() {
initialize()
mandel()
repeat {
; do nothing
}
}
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 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++
}
cx16.FB_set_pixel(max_iter-iter)
}
print_time()
}
}
sub initialize() {
void cx16.screen_set_mode($80)
txt.plot(32, 5)
txt.print("256*240")
txt.plot(32, 6)
txt.print("mandel-")
txt.plot(33, 7)
txt.print("brot")
txt.plot(32, 9)
txt.print("floats")
txt.plot(32, 10)
txt.print_b(max_iter)
txt.print(" iter")
cx16.clock_set_date_time(0, 0, 0, 0)
cx16.r0=0
cx16.FB_init()
}
sub print_time() {
void cx16.clock_get_date_time()
txt.plot(33, 12)
if lsb(cx16.r2) < 10
c64.CHROUT('0')
txt.print_ub(lsb(cx16.r2))
c64.CHROUT(':')
if msb(cx16.r2) < 10
c64.CHROUT('0')
txt.print_ub(msb(cx16.r2))
}
}