26a5751394
Stage 0. Zero-dependency serve.py (static + allowlisted horizons/sbdb/cad proxy, sha256 disk cache with past-span immutability). Three.js via pinned importmap, logarithmic depth, procedural starfield sky (+ Milky Way panorama swap-in), Sun with additive glow, OrbitControls, brass-and-void HUD, scrubbable time bar, central bodyWorld position pass, focus/camera system, hash state. Boots clean, no console errors. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
96 lines
3.9 KiB
JavaScript
96 lines
3.9 KiB
JavaScript
// SOLARGOD shared helpers — time (JD / centuries), math, the ecliptic→world
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// frame map, and human formatters. Pure and dependency-free so verify.html can
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// import it (and ephem.js) with zero Three.js in scope.
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// ---- constants ----
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export const AU_KM = 149597870.7; // 1 astronomical unit in km (IAU 2012)
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export const C_KMS = 299792.458; // speed of light, km/s
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export const MS_PER_DAY = 86400000;
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export const J2000_JD = 2451545.0; // 2000-Jan-01 12:00 TT
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export const UNIX_EPOCH_JD = 2440587.5; // JD of 1970-Jan-01 00:00 UTC
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export const DEG = Math.PI / 180;
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export const RAD = 180 / Math.PI;
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// ---- time ----
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// We treat the sim clock as UTC and ignore the TT/TDB−UTC offset (~69 s in 2026).
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// At interplanetary scale that is < 1e-5 AU even for Mars — noted, deliberately
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// dropped (brief §2). JD from unix-ms: divide by ms/day, add the unix-epoch JD.
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export function jdFromUnixMs(ms) { return ms / MS_PER_DAY + UNIX_EPOCH_JD; }
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export function unixMsFromJd(jd) { return (jd - UNIX_EPOCH_JD) * MS_PER_DAY; }
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// Julian centuries since J2000.0.
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export function centuriesSinceJ2000(jd) { return (jd - J2000_JD) / 36525; }
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// ---- scalar math ----
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export const clamp = (x, lo, hi) => (x < lo ? lo : x > hi ? hi : x);
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export const lerp = (a, b, t) => a + (b - a) * t;
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export function smoothstep(t) { t = clamp(t, 0, 1); return t * t * (3 - 2 * t); }
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// Normalize degrees to (−180, +180]. Must run in float64 AFTER any large
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// subtraction (Mercury's L rate is 149473°/Cy → M can be tens of thousands of
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// degrees before reduction; brief §12).
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export function normDegPM180(d) {
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d = d % 360;
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if (d <= -180) d += 360;
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else if (d > 180) d -= 360;
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return d;
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}
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export const normDeg360 = (d) => ((d % 360) + 360) % 360;
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// ---- frame convention (fixed here once; nothing else maps by hand) ----
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// Heliocentric J2000 ecliptic {x,y,z} [AU or view units] → Three.js world:
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// ecliptic X → world x, ecliptic Z (north) → world y, ecliptic Y → world −z.
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// Keeps the frame right-handed with Y up. `out` is any {x,y,z} sink (Vector3 ok).
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export function eclToWorld(ecl, out = {}) {
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out.x = ecl.x;
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out.y = ecl.z;
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out.z = -ecl.y;
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return out;
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}
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// Inverse, for round-trip checks and picking rays.
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export function worldToEcl(w, out = {}) {
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out.x = w.x;
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out.y = -w.z;
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out.z = w.y;
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return out;
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}
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// ---- formatters ----
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const pad = (n, w = 2) => String(n).padStart(w, '0');
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// "2026-07-15 00:00:00 UTC" from unix-ms.
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export function formatUTC(ms) {
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const d = new Date(ms);
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return `${d.getUTCFullYear()}-${pad(d.getUTCMonth() + 1)}-${pad(d.getUTCDate())} ` +
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`${pad(d.getUTCHours())}:${pad(d.getUTCMinutes())}:${pad(d.getUTCSeconds())} UTC`;
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}
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export function formatUTCDate(ms) {
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const d = new Date(ms);
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return `${d.getUTCFullYear()}-${pad(d.getUTCMonth() + 1)}-${pad(d.getUTCDate())}`;
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}
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export function fmtAU(au) {
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const a = Math.abs(au);
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if (a < 0.001) return `${(au * AU_KM).toFixed(0)} km`;
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if (a < 100) return `${au.toFixed(3)} AU`;
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return `${au.toFixed(1)} AU`;
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}
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export function fmtKm(km) {
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const a = Math.abs(km);
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if (a >= 1e7) return `${(km / 1e6).toLocaleString('en-US', { maximumFractionDigits: 2 })} M km`;
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return `${Math.round(km).toLocaleString('en-US')} km`;
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}
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// Light-time for a distance in AU → "43 min 12 s" / "1 h 08 m" / "8.3 s".
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export function fmtLightTime(au) {
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let s = (au * AU_KM) / C_KMS;
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if (s < 90) return `${s.toFixed(1)} s`;
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const h = Math.floor(s / 3600); s -= h * 3600;
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const m = Math.floor(s / 60); s -= m * 60;
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if (h > 0) return `${h} h ${pad(m)} m`;
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return `${m} min ${pad(Math.floor(s))} s`;
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}
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// Duration in days → "27.3 d" / "1.88 yr".
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export function fmtDuration(days) {
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const a = Math.abs(days);
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if (a < 2) return `${(a * 24).toFixed(1)} h`;
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if (a < 900) return `${a.toFixed(1)} d`;
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return `${(a / 365.25).toFixed(2)} yr`;
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}
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export function fmtSpeed(kms) { return `${kms.toFixed(2)} km/s`; }
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