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.
@alien the F=(v)=> is indeed a function, using the short ES6 arrow syntax. Its purpose is to return a hex value between 0 and 255, (with a preceding 0 when value is less than 16). the hex code is then combined with 2 other hex codes to form a complete, valid color code in the form of #000000. There is a shorter way to do this but it results in exponentially fewer colors. sorry for delayed response.
Using rgb colors instead of hex you dont need to struggel with converting. a=130;for(i=1e3;i--;x.fillStyle=R(a*S(v=i/70-t*4)+a,a*C(v)+a,-a*S(v)+a))x.fillRect(5*i,0,5,2e3) a here uses 130 of the 255 colors to match the same colors.
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)