Ghost of Julia ver2 by andrea270872

function u(t) {

c.width=1920 // clear the canvas
for(i=0;i<9;i++)
x.fillRect(400+i*100+S(t)*300,400,50,200) // draw 50x200 rects

} // 122/140

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    u(t) is called 60 times per second.
    t: Elapsed time in seconds.
    S: Shorthand for Math.sin.
    C: Shorthand for Math.cos.
    T: Shorthand for Math.tan.
    R: Function that generates rgba-strings, usage ex.: R(255, 255, 255, 0.5)
    c: A 1920x1080 canvas.
    x: A 2D context for that canvas.

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andrea270872

function u(t) {

I=(t*3350)%2e3;J=(t*94)%1e3
A=I/1e3-1;B=J/600-1
i=0;while(((A*A+B*B)<4)&&(i<25))[A,B]=[A*A-B*B-.8,2*A*B+.2,i++]
x.fillRect(I,J,i,i)

Mar 7 2019 5:29 PM UTC

}// 131/140

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Ghost of Julia ver2

u/andrea270872

/* LOGIC The point (I,J) depends on t and scans the screen from top-left to bottom-right, then restarts. It also hops of circa 50 pixels in both directions. The point (A,B) is a scaled and translated version of (I,J); (A,B) is centered arund (0,0) and goes approximately from -1,5 to +1.5 in both directions. The loop is a simplified version of the Julia iterated fractal loop: - i starts from 0, and goes max to 25 iterations, and the point starts at z=A+i*B - the function being computed is: Z=Z^2+(-0.8,+0.2) separating real and imaginary part, the formula is: A = A*A-B*B-.8 AND B = 2*A*B+.2 and the notation [A,B] saves me from using a temp variable. The loop exits if: - i is 25 or - distance of (A,B) from (0,0) is more than 2 */
u/f8f82804

#dither #halftone #fractal


      u(t) is called 60 times per second.
      t: elapsed time in seconds.
      c: A 1920x1080 canvas.
      x: A 2D context for that canvas.
      S: Math.sin
      C: Math.cos
      T: Math.tan
      R: Generates rgba-strings, ex.: R(255, 255, 255, 0.5)

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