51 lines
2.0 KiB
JavaScript
51 lines
2.0 KiB
JavaScript
function clamp(min, val, max) {
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if (val < min) {
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val = min;
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}
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if (val > max) {
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val = max;
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}
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return val;
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}
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const scrollchecks = () => {
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var el = document.getElementById("header");
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el.style.backgroundPositionY = 50 + (document.documentElement.scrollTop/el.scrollHeight) / 2 * 100 + "%";
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Array.from(document.getElementsByClassName("scrolly")).forEach(el => {
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let box = el.getBoundingClientRect();
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if (box.bottom < 0 || box.top >= window.innerHeight) {
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el.classList.add("scrolly-out");
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el.classList.remove("scrolly-in");
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el.classList.remove("scrolly-onedge");
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}
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else {
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el.classList.remove("scrolly-out");
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el.classList.add("scrolly-in");
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el.classList.add("scrolly-entered");
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if (box.top <= 0 || box.bottom >= window.innerHeight) {
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el.classList.add("scrolly-onedge");
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}
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else {
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el.classList.remove("scrolly-onedge");
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}
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}
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if (box.top + box.height / 2 <= window.innerHeight / 2) {
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el.classList.add("scrolly-tophalf");
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el.classList.remove("scrolly-bottomhalf");
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}
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else {
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el.classList.remove("scrolly-tophalf");
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el.classList.add("scrolly-bottomhalf");
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}
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});
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var perc = clamp(0, document.getElementById("outer").scrollTop / (window.innerHeight / 2), 1);
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document.querySelector("#headin > h1").style.fontSize = 2 + 4 * (1 - perc) + "em";
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document.querySelector("#links").style.opacity = perc;
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};
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window.addEventListener("scroll", scrollchecks);
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window.addEventListener("scrollend", scrollchecks);
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window.addEventListener("wheel", scrollchecks);
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window.addEventListener("resize", scrollchecks);
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window.addEventListener("load", scrollchecks);
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window.addEventListener("touchmove", scrollchecks);
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setInterval(scrollchecks, 250); // Computers are fast and scrolling in JavaScript is dumb. Shoot me.
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