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Add support for fractional and NTSC style framerates #1

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Add support for fractional and NTSC style framerates #1

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75 changes: 64 additions & 11 deletions index.html
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Original file line number Diff line number Diff line change
Expand Up @@ -56,7 +56,7 @@

#settings {
width: 100vw;
height: 64px;
height: 70px;
overflow: hidden;
font-size: 16px;
white-space: nowrap;
Expand Down Expand Up @@ -120,6 +120,10 @@
color: lime;
}

input[id="fps"] {
width: 100px;
}

#help {
display: none;
}
Expand Down Expand Up @@ -201,14 +205,15 @@
</ul>
<div id="ball"></div>
<div id="boxes"></div>
<div id="settings"><label for="fps">FPS: <input type="text" id="fps" size="3" value="60" /></label> / <label
<div id="settings"><label for="fps">FPS: <input type="text" id="fps" size="8" value="60" /></label> / <label
for="auto"><input type="checkbox" id="auto" checked autocomplete="off">Auto</label>
≈<span id="fps2"></span> |
<label for="start"><input type="checkbox" id="start" autocomplete="off">🏃RUN TEST</label> |
<label for="trail"><input type="checkbox" id="trail" checked autocomplete="off"><span
style="color: #900000">⋯</span>Trail</label> |
<label for="noise"><input type="checkbox" id="noise" autocomplete="off">🥵Noise</label> |
<label for="tone"><input type="checkbox" id="tone" autocomplete="off">🎺Tone</label>
<div style="font-size: 14px">Supported formats: 60 (integer), 59.94 (fractional), 60000/1001 (NTSC)</div>
<div id="calc">Calculator | <label for="a">Host: <input type="text" id="a" /></label> ≥ <label for="b">Client:
<input type="text" id="b" /></label> <span id="delay"></span>
</div>
Expand Down Expand Up @@ -294,6 +299,20 @@
}
}

function parseFpsInput(value) {
if (value.includes('/')) {
const [numerator, denominator] = value.split('/').map(Number);
if (denominator && denominator !== 0) {
return numerator / denominator;
}
return NaN;
} else if (value.includes('.')) {
return parseFloat(value);
} else {
return parseInt(value);
}
}

const fpsTick = function () {
times.push(performance.now());
const ms = times[times.length - 1] - times[0];
Expand Down Expand Up @@ -349,9 +368,42 @@
if (document.getElementById("auto").checked) {
refreshLoop();
} else {
if (timer)
if (timer) {
timer.cancel();
timer = new interval(1000 / parseInt(document.getElementById("fps").value), nextFrame);
}
const fpsInput = document.getElementById("fps").value;
const fpsValue = parseFpsInput(fpsInput);
if (isNaN(fpsValue) || fpsValue <= 0) {
alert("Invalid FPS value");
return;
}

timer = {
cancel: () => clearTimeout(timer.timeoutId),
run: () => {
const intervalMs = 1000 / fpsValue;
let start = performance.now();
let frameCount = 0;

const tick = () => {
nextFrame();
frameCount++;

const nextFrameTime = start + frameCount * intervalMs;
const now = performance.now();
let delay = nextFrameTime - now;

if (delay < 0) {
// If we are behind, skip ahead
delay = 0;
start = now;
frameCount = 0;
}
timer.timeoutId = setTimeout(tick, delay);
};
timer.timeoutId = setTimeout(tick, intervalMs);
}
};
timer.run();
}
if (document.getElementById("noise").checked)
Expand Down Expand Up @@ -392,13 +444,14 @@
stop();
}
const calc = () => {
var a = parseInt(document.getElementById("a").value);
var b = parseInt(document.getElementById("b").value);
var realFps = fps > 0 ? fps : parseInt(document.getElementById("fps").value);
var delta = a - b;
var ms = (1 / realFps) * delta * 1000;
document.getElementById("delay").innerText = " = " + delta + " frames = " + ms.toFixed(2) + "ms @ " + realFps.toFixed(2) + " FPS";
}
const a = parseInt(document.getElementById("a").value);
const b = parseInt(document.getElementById("b").value);
const fpsInput = document.getElementById("fps").value;
const realFps = parseFpsInput(fpsInput) || fps;
const delta = a - b;
const ms = (1 / realFps) * delta * 1000;
document.getElementById("delay").innerText = ` = ${delta} frames = ${ms.toFixed(2)}ms @ ${realFps.toFixed(5)} FPS`;
};
document.getElementById("a").onchange = calc;
document.getElementById("b").onchange = calc;
document.getElementById("a").onkeyup = calc;
Expand Down