mirror of
https://github.com/irmen/prog8.git
synced 2024-07-05 22:29:04 +00:00
68 lines
1.6 KiB
Lua
68 lines
1.6 KiB
Lua
%import c64lib
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%import c64utils
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%import c64flt
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%zeropage basicsafe
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main {
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const uword width = 30
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const uword height = 20
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const ubyte max_iter = 16
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sub start() {
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c64scr.print("calculating mandelbrot fractal...")
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c64.TIME_HI=0
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c64.TIME_MID=0
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c64.TIME_LO=0
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ubyte pixelx
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ubyte pixely
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; TODO fix compiler - calculation is broken now
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for pixely in 0 to height-1 {
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float yy = (pixely as float)/0.4/height - 1.0
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for pixelx in 0 to width-1 {
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float xx = (pixelx as float)/0.3/width - 2.2
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float xsquared = 0.0
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float ysquared = 0.0
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float x = 0.0
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float y = 0.0
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ubyte iter = 0
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while (iter<max_iter and xsquared+ysquared<4.0) {
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y = x*y*2.0 + yy
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x = xsquared - ysquared + xx
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xsquared = x*x
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ysquared = y*y
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iter++
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}
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c64scr.setcc(pixelx+4, pixely+1, 160, max_iter-iter)
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}
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}
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float duration = ((c64.TIME_LO as float)
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+ 256.0*(c64.TIME_MID as float)
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+ 65536.0*(c64.TIME_HI as float))/60.0
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c64scr.plot(0, 21)
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c64scr.print("finished in ")
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c64flt.print_f(duration)
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c64scr.print(" seconds!\n")
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check_eval_stack()
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}
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sub check_eval_stack() {
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if X!=255 {
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c64scr.print("stack x=")
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c64scr.print_ub(X)
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c64scr.print(" error!\n")
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}
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}
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}
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