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.
Clever idea. If you do fill you can re-use the rect you did for clipping. onmousemove=e=>T=e.x;c.width=568;with(x)for(font="7cm'",i=2;i--;i&&clip(fill(rect(0,0,T,568))))fillText(i?"🧔":"💀",92,250+S(t*9)*(T>500)*4)
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)