zenno/mspeed: calculator for front runner mechanical speed bonuses

zenno/src/routes/mspeed/SpeedDur.svelte

@@ -0,0 +1,33 @@
+<script lang="ts">
+	import { HORSE_LENGTH, speedGain } from '$lib/race';
+	import type { Snippet } from 'svelte';
+
+	interface Props {
+		children: Snippet;
+		speed: number;
+		dur: number;
+		accel: number;
+		decel: number | number[];
+	}
+
+	function fmtp(x: number): string {
+		return x >= 0 ? '+' + x.toFixed(3) : x.toFixed(3);
+	}
+
+	const { children, speed, dur, accel, decel }: Props = $props();
+	const decels = $derived([decel].flat(1));
+
+	const gain = $derived(decels.map((d) => speedGain(speed, accel, d, dur) / HORSE_LENGTH));
+	const text = $derived(gain.map(fmtp).join(' &ndash; '));
+</script>
+
+<div
+	class="m-2 flex h-full w-full max-w-80 flex-1 flex-col rounded-md border p-2 text-center shadow-sm transition-shadow hover:shadow-md"
+>
+	<div class="block">{@render children()}</div>
+	<span class="block text-xl">{@html text} L</span>
+	<div class="flex flex-row">
+		<span class="flex-1 text-xs">{fmtp(speed)} m/s</span>
+		<span class="flex-1 text-xs">{dur.toFixed(3)} s</span>
+	</div>
+</div>