mirror of https://github.com/irmen/prog8.git
55 lines
1.4 KiB
Lua
55 lines
1.4 KiB
Lua
%import graphics
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%import floats
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%import test_stack
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%zeropage floatsafe
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; Draw a mandelbrot in graphics mode (the image will be 256 x 200 pixels).
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; NOTE: this will take an eternity to draw on a real c64. A CommanderX16 is a bit faster.
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; even in Vice in warp mode (700% speed on my machine) it's slow, but you can see progress
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; Note: this program can be compiled for multiple target systems.
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main {
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const uword width = 320
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const ubyte height = 200
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const ubyte max_iter = 16
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sub start() {
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graphics.enable_bitmap_mode()
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uword pixelx
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ubyte pixely
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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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if iter & 1 !=0
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graphics.plot(pixelx, pixely)
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}
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}
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; graphics.disable_bitmap_mode()
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; test_stack.test()
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repeat {
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}
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}
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}
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