d/24130 by ciaccodavide

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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ciaccodavide

function u(t) {

for(c.width|=i=3e2,d=1-i/2e2;i--;)x.beginPath(x.arc(960,540+S(t+i/3*99)*99*d,i*4,0,7),x.stroke())

Oct 15 2021 11:55 AM UTC

}// 97/140

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u/joeytwiddle

I perceive movement inwards, but the code says the only movement is up and down! 🤯 Want proof? Try growing i slowly with i=t*3|0. Or try reversing the movement with t-i/3 instead of t+i/3.
u/joeytwiddle

This is also a rare-ish example of inverted Moire, by which I mean the interference patterns which most stand out are white rather than black.
u/joeytwiddle

The remix simplifies the effect, making it a little easier to see what's happening.


      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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