8 primary colours flashing (sorry) by joeytwiddle

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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joeytwiddle

function u(t) {

c.width|=W=500,J=255
for(i=8;i--;x.fillRect(W*X,W*Y,W,W))X=i%4,Y=i>>2,k=(3+i)/t,f=t%k<k/2?i:i^7,x.fillStyle=R(J*(f&1),J*((f&2)/2),J*((f&4)))

Jun 14 2026 10:59 PM UTC

}// 140/140

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8 primary colours flashing (sorry)

u/joeytwiddle

I just made this to explain my 8-bit childhood trauma to a friend
u/joeytwiddle

Long ago I noticed that the brightness of the colours increases in an alternating fashion: 0,4, 1,5, 2,6, 3,7. Paste ,c.style.filter='saturate(0%)',t=0 at the top to see this. It seemed to me to be intentional but odd. Now I realise it's simply because blue is the darkest primary, with red and green following. So we can get a smooth gradient by moving J*(f&1) from the first argument to the last.


      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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