d/3036 by artfarnaa

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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artfarnaa

function u(t) {

 for (c.width|=a=200;--a;x.arc(960+S(G+t)*400,
 540+C(t+G*1)*400,a%2*137*Math.abs(S(t))*4,0,
 6.2832))x.moveTo(G=a/2|0,0)
 x.fill('evenodd')

Aug 8 2017 1:52 AM UTC

}// 140/140

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Show more comments…
u/kchplr

Great !
u/sigveseb

Awesome!
u/ninerdelta

stupid question, but why c.width|=a=200? I was tinkering with this code and just made it a=200 and the fps drops significantly.
u/kchplr

ninerdelta: I think that the reason is that c.width|=something is not only clearing the canvas but also the 2d context. Without it each iterations keeps adding arcs to the current path, by the 10th frames there are 2000 arcs to redraw, by the 50th frames there are 10000, etc. In a, err, "non-cold golfing codebase" you could avoid this by using beginPath and closePath.
u/kchplr

"cold golfing", superb. I meant code golfing...
u/ninerdelta

ah that makes sense, thanks!
u/donbright

now this is fine work


      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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