GODSIGH/js/lib.js
jing 3ca9409f31 wave2 phase 2: wildfires layer (real NASA EONET)
New js/layers/fires.js — fetches EONET open wildfire events directly (ACAO:*),
refreshes every 15 min, rebuilt wholesale (no time dynamics — EONET events are
slow-moving). Uses the latest dated geometry per event; Point coords direct,
Polygon reduced to first-ring centroid. Flame-teardrop billboard (new
lib.flameGlyph, drawn in #ff7a1a with dark outline, shared canvas), aggressive
label translucency so dense California/Australia clusters stay legible, cap 500.
HUD row "Wildfires (NASA EONET)".

PITFALL handled: EONET mislabels Content-Type as application/rss+xml but the
body is JSON — we call res.json() and never gate on the header.

Verified in browser: 500 fires, all finite positions, glyphs render over
North America, zero console errors.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-07-13 16:05:28 +10:00

90 lines
2.5 KiB
JavaScript

// Shared helpers used across layers. Cesium and satellite are CDN globals.
const Cesium = window.Cesium;
// Build an offscreen canvas glyph for a BillboardCollection.
export function makeGlyphCanvas(size, drawFn) {
const c = document.createElement('canvas');
c.width = size;
c.height = size;
drawFn(c.getContext('2d'), size);
return c;
}
// White upward-pointing triangle (aircraft). Tinted per-billboard via .color.
export function aircraftGlyph() {
return makeGlyphCanvas(32, (g) => {
g.fillStyle = '#ffffff';
g.beginPath();
g.moveTo(16, 2);
g.lineTo(28, 30);
g.lineTo(16, 23);
g.lineTo(4, 30);
g.closePath();
g.fill();
});
}
// Upward teardrop/flame (wildfires). Drawn directly in `hex` with a dark
// outline — one shared canvas reused across every fire billboard.
export function flameGlyph(hex) {
return makeGlyphCanvas(28, (g, s) => {
const cx = s / 2;
g.beginPath();
g.moveTo(cx, 3); // pointed top
g.bezierCurveTo(s * 0.86, s * 0.34, s * 0.80, s * 0.72, cx, s - 4);
g.bezierCurveTo(s * 0.20, s * 0.72, s * 0.14, s * 0.34, cx, 3);
g.closePath();
g.fillStyle = hex;
g.fill();
g.lineWidth = 2;
g.strokeStyle = '#0a0f14';
g.stroke();
});
}
// White diamond (ships).
export function shipGlyph() {
return makeGlyphCanvas(28, (g) => {
g.fillStyle = '#ffffff';
g.beginPath();
g.moveTo(14, 2);
g.lineTo(26, 14);
g.lineTo(14, 26);
g.lineTo(2, 14);
g.closePath();
g.fill();
});
}
// Great-circle initial bearing, degrees (0 = north, clockwise).
export function bearingDeg(lat1, lon1, lat2, lon2) {
const toR = Math.PI / 180;
const p1 = lat1 * toR;
const p2 = lat2 * toR;
const dl = (lon2 - lon1) * toR;
const y = Math.sin(dl) * Math.cos(p2);
const x = Math.cos(p1) * Math.sin(p2) - Math.sin(p1) * Math.cos(p2) * Math.cos(dl);
return (Math.atan2(y, x) * 180 / Math.PI + 360) % 360;
}
// Aircraft altitude → band color.
export function altitudeColor(CONFIG, altMeters) {
const c = CONFIG.colors;
if (altMeters == null) return c.aircraftHigh;
if (altMeters < 3000) return c.aircraftLow;
if (altMeters < 9000) return c.aircraftMid;
return c.aircraftHigh;
}
// CSS hex → Cesium.Color, optional alpha.
export function cz(hex, alpha) {
const col = Cesium.Color.fromCssColorString(hex);
return alpha == null ? col : col.withAlpha(alpha);
}
// Billboard screen-space rotation (CCW) for a compass heading (CW from north).
export function headingToRotation(headingDeg) {
return -Cesium.Math.toRadians(headingDeg || 0);
}