Paint! Works best in fullscreen, unfort… by FireFly

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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FireFly

function u(t) {

X=0;X||(c.onmousemove=(e)=>(x.lineTo(X=e.offsetX/c.offsetWidth*1920,Y=e.offsetY/c.offsetHeight*1080),x.beginPath(x.stroke()),x.moveTo(X,Y)))

Feb 28 2017 3:28 PM UTC

}// 140/140

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Paint! Works best in fullscreen, unfortunately I can't fit detection of mouse button to toggle painting (also not sure how, without two more event handlers…)

u/Kalanchoe

Nice! moveTo is unnecessary if you already have beginPath and lineTo; c.offsetWidth/1920 and c.offsetHeight/1080 are both equal to about .2958 (at least on the desktop): https://www.dwitter.net/d/809
u/FireFly

Won't c.offsetWidth and c.offsetHeight change when the user goes fullscreen? I wanted to support both not-fullscreen and fullscreen equally well. Good point about moveTo!


      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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