So I am working on my wikipedia project and had an idea where I want the text to draw itself on the page and found this code on the internet to achieve this. So i have been trying to understand exactly what it does line by line but am stuck on why it surrounds the function call with a ( and calls an empty () after it. If anyone could explain the reasoning behind this that would be awesome here is the code… Also I put comments on the sections that confuse me.
var ctx = document.querySelector("canvas").getContext("2d"),
dashLen = 220, dashOffset = dashLen, speed = 5,
txt = "STROKE-ON CANVAS", x = 30, i = 0;
ctx.font = "50px Comic Sans MS, cursive, TSCu_Comic, sans-serif";
ctx.lineWidth = 5; ctx.lineJoin = "round"; ctx.globalAlpha = 2/3;
ctx.strokeStyle = ctx.fillStyle = "#1f2f90";
(function loop() { // WHY DOES THIS HAVE A ( BEFORE FUNCTION//
ctx.clearRect(x, 0, 60, 150);
ctx.setLineDash([dashLen - dashOffset, dashOffset - speed]); // create a long dash mask
dashOffset -= speed; // reduce dash length
ctx.strokeText(txt[i], x, 90); // stroke letter
if (dashOffset > 0) requestAnimationFrame(loop); // animate
else {
ctx.fillText(txt[i], x, 90); // fill final letter
dashOffset = dashLen; // prep next char
x += ctx.measureText(txt[i++]).width + ctx.lineWidth * Math.random();
ctx.setTransform(1, 0, 0, 1, 0, 3 * Math.random()); // random y-delta
ctx.rotate(Math.random() * 0.005); // random rotation
if (i < txt.length) requestAnimationFrame(loop);
}
})(); // WHY IS THERE A EMPTY () HERE?