Animation slowdown detector (does not h… by pavel

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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pavel

function u(t) {

s=t?s:new Date;c.width|=0;x.font='8em"';['t',t,'system clock',w=(new Date-s)/1e3,'ratio',t/w].map((s,i)=>x.fillText(s,i%2*800,(2+i>>1)*99))

Nov 13 2018 10:06 PM UTC

}// 139/140

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Animation slowdown detector (does not handle pausing)

u/pavel

I've noticed animations being slower on my iphone. This dweet shows a ratio of 1 on my macbook but 0.558 on my phone!
u/pavel

This is a Safari issue; runs at .558 on phone and mac. Mac Chrome runs at 1.
u/prplz

Same result on my iPhone/safari too
u/magna

See also d/3307
u/katkip

Mine is 1.1 on pc


      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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