2b:null 2c:["$","title",null,{"children":"Eclipses | nxrix | Observable"}] 31:Tafa,viewof selectedEclipse = { const list = eclipseList ?? []; const el = html`

`; el.style.cursor = "pointer"; el.style.userSelect = "none"; const isLocal = mode === "Local"; const chip = (kind) => html`${kind.charAt(0).toUpperCase() + kind.slice(1)}`; function select(ecl) { el.value = ecl; state.selectedEclipse = ecl; for (const r of el.querySelectorAll("tr")) { const on = r._ecl === ecl; r.style.outline = on ? "1px solid currentColor" : ""; r.style.outlineOffset = on ? "2px" : ""; r.style.borderRadius = on ? "2px" : ""; //r.style.background = on ? "#add8e6" : ""; //r.style.fontWeight = on ? "bold" : ""; } el.dispatchEvent(new CustomEvent("input")); } if (!list.length) { el.value = null; el.appendChild( html`

${ isLocal && !marker ? "No point selected yet." : "No eclipses found." }

` ); el.dispatchEvent(new CustomEvent("input")); return el; } const head = isLocal ? [ "Peak (UTC)", "At your Marker", "Obscuration", "Partial start", "Partial end", "Sun alt.", "Central phase" ] : ["Peak (UTC)", "Kind", "Max obscuration", "Greatest eclipse"]; const tbody = html`${list.map((ecl) => { const cells = isLocal ? [ html`${Astro.fmtDate(ecl.peak)} ${Astro.fmtTime( ecl.peak )}`, html`${chip(ecl.kind)}`, html`${(100 * ecl.obscuration).toFixed(1)}%`, html`${Astro.fmtTime(ecl.partialBegin)}`, html`${Astro.fmtTime(ecl.partialEnd)}`, html`${ecl.peakAltitude.toFixed(0)}°`, html`${ ecl.centralDuration != null ? Astro.fmtDur(ecl.centralDuration) : "-" }` ] : [ html`${Astro.fmtDate(ecl.peak)} ${Astro.fmtTime( ecl.peak )}`, html`${chip(ecl.kind)}`, html`${ ecl.obscuration != null ? (100 * ecl.obscuration).toFixed(1) + "%" : "-" }`, html`${ ecl.obscuration != null ? Astro.fmtLatLon(ecl.focus) : "-" }` ]; return html`${cells}`; })}`; [...tbody.children].forEach((tr, i) => { tr._ecl = list[i]; tr.addEventListener("click", () => select(list[i])); }); el.appendChild(html`${head.map((h) => html``)}${tbody}

${h}

`); const i = list.find( (e) => e.key.substr(1, 10) === state.selectedEclipse?.key?.substr(1, 10) ); select(i || list[0]); return el; }32:T4bb,{ const normLunar = (l) => { const t = l.peak.date.getTime(); const start = t - l.sd_penum * 60000; const end = t + l.sd_penum * 60000; return { key: "Lunar" + l.peak.date.toISOString(), mode: "Lunar", kind: l.kind, peak: { date: l.peak.date }, window: { start: new Date(start), end: new Date(end) }, // handy extras if your UI colors phases: partial_begin: l.sd_partial > 0 ? new Date(t - l.sd_partial * 60000) : null, total_begin: l.sd_total > 0 ? new Date(t - l.sd_total * 60000) : null }; }; const le = []; if (!selectedEclipse) return md`No lunar eclipses found.`; const p = selectedEclipse.peak.date.getTime(); const minDate = p - 18 * 86400000; const maxDate = p + 18 * 86400000; let l = Astronomy.SearchLunarEclipse(new Date(minDate)); while (l) { const t = l.peak.date.getTime(); if (t > maxDate) break; if (t >= minDate) le.push(normLunar(l)); l = Astronomy.NextLunarEclipse(l.peak); } if (le.length > 0) { return md`Lunar eclipses: \n${le .map((i) => "**" + Astro.fmtUTC(i.window.start) + "**") .join(" \n")}`; } else { return md`No lunar eclipses found.`; } }33:T2794,renderer = { const renderer = new THREE.WebGLRenderer({ antialias: true, preserveDrawingBuffer: true }); errors.innerText = "No errors :)"; errors.style.color = "green"; function handleSource(string, errorLine) { const lines = string.split("\n"); const lines2 = []; const from = Math.max(errorLine - 6, 0); const to = Math.min(errorLine + 6, lines.length); for (let i = from; i < to; i++) { const line = i + 1; lines2.push(`${line === errorLine ? ">" : " "} ${line}: ${lines[i]}`); } return lines2.join("\n"); } function getShaderErrors(gl, shader, type) { const status = gl.getShaderParameter(shader, gl.COMPILE_STATUS); const shaderInfoLog = gl.getShaderInfoLog(shader) || ""; const errors = shaderInfoLog.trim(); if (status && errors === "") return ""; const errorMatches = /ERROR: 0:(\d+)/.exec(errors); if (errorMatches) { const errorLine = parseInt(errorMatches[1]); return ( errors + "\n\n" + handleSource(gl.getShaderSource(shader), errorLine) ); } else { return errors; } } renderer.debug.onShaderError = ( gl, program, glVertexShader, glFragmentShader ) => { const programInfoLog = gl.getProgramInfoLog(program) || ""; const fragmentShaderInfoLog = gl.getShaderInfoLog(glFragmentShader) || ""; const programLog = programInfoLog.trim(); const fragmentLog = fragmentShaderInfoLog.trim(); if (gl.getProgramParameter(program, gl.LINK_STATUS) === false) { const fragmentErrors = getShaderErrors(gl, glFragmentShader, "fragment"); errors.innerText = fragmentErrors; errors.style.color = "red"; } }; const canvas = renderer.domElement; canvas.style.maxWidth = "100%"; canvas.style.borderRadius = "8px"; const camera = new THREE.PerspectiveCamera(45, 1, 0.25, 24000); camera.position.setFromSphericalCoords(3.2, 1.5, 2.0); let needsRender = true; const controls = new THREE.OrbitControls(camera, canvas); controls.rotateSpeed = 0.4; controls.enablePan = false; //controls.enableZoom = false; controls.minDistance = 2.0; controls.maxDistance = 6.0; controls.minPolarAngle = 0.05; controls.maxPolarAngle = Math.PI - 0.05; controls.addEventListener("change", () => { needsRender = true; }); const scene = new THREE.Scene(); const uniforms = { uDayTex: { value: textures.day }, uNightTex: { value: textures.night }, uSunPos: { value: new THREE.Vector3(23000, 0, 0) }, uMoonPos: { value: new THREE.Vector3(0, 0, 5000) }, uRealShadows: { value: true } }; const maxAnisotropy = renderer.capabilities.getMaxAnisotropy(); const optimizeTex = (tex) => { if (!tex) return; tex.anisotropy = maxAnisotropy; tex.wrapS = THREE.RepeatWrapping; tex.wrapT = THREE.ClampToEdgeWrapping; tex.minFilter = THREE.LinearMipMapLinearFilter; tex.magFilter = THREE.LinearFilter; tex.generateMipmaps = true; tex.needsUpdate = true; //tex.colorSpace = THREE.SRGBColorSpace; }; optimizeTex(uniforms.uDayTex.value); optimizeTex(uniforms.uNightTex.value); const earth = new THREE.Mesh( new THREE.SphereGeometry(1, 160, 120), new THREE.ShaderMaterial({ uniforms, vertexShader: earthVertexShader, fragmentShader: earthFragmentShader }) ); scene.add(earth); const atmo = new THREE.Mesh( new THREE.SphereGeometry(1.02, 96, 64), new THREE.ShaderMaterial({ uniforms: { uSunPos: uniforms.uSunPos, uMoonPos: uniforms.uMoonPos, uRealShadows: uniforms.uRealShadows }, vertexShader: atmoVertexShader, fragmentShader: atmoFragmentShader, transparent: true, blending: THREE.AdditiveBlending, depthWrite: false //side: THREE.DoubleSide, //forceSinglePass: true }) ); scene.add(atmo); function makeGlowTexture(size = 256) { const c = document.createElement("canvas"); c.width = c.height = size; const ctx = c.getContext("2d"); const g = ctx.createRadialGradient( size / 2, size / 2, 0, size / 2, size / 2, size / 2 ); g.addColorStop(0.0, "rgba(255,252,240,1)"); g.addColorStop(0.25, "rgba(255,236,180,0.85)"); g.addColorStop(0.5, "rgba(255,190,90,0.30)"); g.addColorStop(0.75, "rgba(255,150,50,0.07)"); g.addColorStop(1.0, "rgba(255,130,30,0)"); ctx.fillStyle = g; ctx.fillRect(0, 0, size, size); return new THREE.CanvasTexture(c); } const sunGlowTex = makeGlowTexture(); const sunGlow = new THREE.Sprite( new THREE.SpriteMaterial({ map: sunGlowTex, color: 0xffe9b0, blending: THREE.AdditiveBlending, transparent: true, depthWrite: false, depthTest: true }) ); sunGlow.scale.setScalar(109 * 8); sunGlow.position.set(0, 0, 23000); scene.add(sunGlow); const sunMesh = new THREE.Mesh( new THREE.SphereGeometry(109, 48, 48), new THREE.MeshBasicMaterial({ color: 0xfff2a8 }) ); sunMesh.position.set(0, 0, 23000); scene.add(sunMesh); const moonMesh = new THREE.Mesh( new THREE.SphereGeometry(0.27, 32, 32), new THREE.MeshBasicMaterial({ color: 0x888888 }) ); moonMesh.position.set(0, 0, 60); scene.add(moonMesh); const markerMesh = new THREE.Group(); const dot = new THREE.Mesh( new THREE.SphereGeometry(0.011, 16, 12), new THREE.MeshBasicMaterial({ color: 0xffffff }) ); const ring = new THREE.Mesh( new THREE.RingGeometry(0.024, 0.034, 40), new THREE.MeshBasicMaterial({ color: 0xffffff, side: THREE.DoubleSide, transparent: true, opacity: 0.5 }) ); markerMesh.add(dot, ring); markerMesh.visible = false; scene.add(markerMesh); const MAXPTS = 256; const trailGeo = new THREE.BufferGeometry(); trailGeo.setAttribute( "position", new THREE.BufferAttribute(new Float32Array(MAXPTS * 3), 3) ); const trail = new THREE.Line( trailGeo, new THREE.LineBasicMaterial({ color: 0xffffff, transparent: true, opacity: 0.5, linecap: "round", linejoin: "round", linewidth: 4 }) ); trail.frustumCulled = false; trail.visible = false; scene.add(trail); const pick = (e) => { const r = canvas.getBoundingClientRect(); raycaster.setFromCamera( new THREE.Vector2( ((e.clientX - r.left) / r.width) * 2 - 1, -((e.clientY - r.top) / r.height) * 2 + 1 ), camera ); const hit = raycaster.intersectObject(earth, false)[0]; if (!hit) return; const p = hit.point.clone().normalize(); const ll = Astro.sceneToLatLon([p.x, p.y, p.z]); markerMesh.position.copy(p).multiplyScalar(1.006); ring.quaternion.setFromUnitVectors(new THREE.Vector3(0, 0, 1), p); markerMesh.visible = true; mutable marker = { lat: +ll.lat.toFixed(2), lon: +ll.lon.toFixed(2) }; needsRender = true; }; const raycaster = new THREE.Raycaster(); let down = null; const onPointerDown = (e) => { if (e.button === 0) down = { x: e.clientX, y: e.clientY, moved: 0 }; }; const onPointerMove = (e) => { if (!down) return; down.moved += Math.abs(e.clientX - down.x) + Math.abs(e.clientY - down.y); down.x = e.clientX; down.y = e.clientY; }; const onPointerUp = (e) => { if (down && down.moved < 6) pick(e); down = null; }; canvas.addEventListener("pointerdown", onPointerDown); canvas.addEventListener("pointermove", onPointerMove); canvas.addEventListener("pointerup", onPointerUp); renderer.api = { setRealShadows(v) { uniforms.uRealShadows.value = v; needsRender = true; }, setBodies(pos) { if (pos) { const { sun, moon } = pos; sunMesh.position.set(sun[0], sun[1], sun[2]); sunGlow.position.copy(sunMesh.position); moonMesh.position.set(moon[0], moon[1], moon[2]); uniforms.uSunPos.value.fromArray(sun); uniforms.uMoonPos.value.fromArray(moon); } else { uniforms.uMoonPos.value.set(0, 0, 5000); } needsRender = true; }, setTrail(points) { const a = trailGeo.attributes.position; const n = Math.min(points ? points.length : 0, MAXPTS); for (let i = 0; i < n; i++) { a.array[3 * i] = points[i][0]; a.array[3 * i + 1] = points[i][1]; a.array[3 * i + 2] = points[i][2]; } trailGeo.setDrawRange(0, n); a.needsUpdate = true; trail.visible = n > 1; needsRender = true; } }; let running = true; const loop = () => { if (!running) return; if (needsRender) { needsRender = false; renderer.render(scene, camera); } requestAnimationFrame(loop); }; loop(); const resize = (w, h, r = 1) => { renderer.setPixelRatio(r); renderer.setSize(w, h,false); const a = w / h; camera.aspect = a; camera.zoom = a <= 1 ? a : 1; camera.updateProjectionMatrix(); renderer.render(scene, camera); }; const resizeEvent = () => { const z = Math.min(window.innerWidth, 512 * 1.40625); const w = z; const h = z * 0.75; resize(w, h, devicePixelRatio); }; window.addEventListener("resize", resizeEvent); resizeEvent(); renderer.resize = resize; renderer.resizeEvent = resizeEvent; invalidation.then(() => { running = false; canvas.removeEventListener("pointerdown", onPointerDown); canvas.removeEventListener("pointermove", onPointerMove); canvas.removeEventListener("pointerup", onPointerUp); window.removeEventListener("resize", resizeEvent); controls.dispose(); scene.traverse((obj) => { if (obj.isMesh || obj.isSprite || obj.isLine) { if (obj.geometry) obj.geometry.dispose(); if (obj.material) { if (Array.isArray(obj.material)) { obj.material.forEach((m) => m.dispose()); } else { obj.material.dispose(); } } } }); sunGlowTex.dispose(); renderer.dispose(); if (renderer.forceContextLoss) renderer.forceContextLoss(); }); return renderer; }34:T79a,searchEclipses = (mode, point, count) => { const normGlobal = (g) => { const hit = Astro.shadowAxisHit(g.peak.date, g.kind); const ll = Astro.sceneToLatLon(hit.scene); return { key: "G" + g.peak.date.toISOString(), mode: "Global", kind: g.kind, obscuration: g.obscuration ?? null, peak: g.peak, window: { start: Astro.addH(g.peak, -3), end: Astro.addH(g.peak, +3) }, focus: { scene: hit.scene, lat: ll.lat, lon: ll.lon }, local: null }; }; const normLocal = (l) => { const hit = Astro.shadowAxisHit(l.peak.time.date, l.kind); const pb = l.partial_begin ? l.partial_begin.time : null; const pe = l.partial_end ? l.partial_end.time : null; return { key: "L" + l.peak.time.date.toISOString(), mode: "Local", kind: l.kind, obscuration: l.obscuration, peak: l.peak.time, peakAltitude: l.peak.altitude, partialBegin: pb, partialEnd: pe, centralDuration: l.total_begin && l.total_end ? (l.total_end.time.date - l.total_begin.time.date) / 1000 : null, window: { start: pb ?? Astro.addH(l.peak.time, -1), end: pe ?? Astro.addH(l.peak.time, +1) }, focus: { scene: hit.scene, ...Astro.sceneToLatLon(hit.scene) }, local: l }; }; const out = []; if (mode === "Global") { let g = Astronomy.SearchGlobalSolarEclipse(new Date()); for (let i = 0; g && out.length < count && i < 100; i++) { out.push(normGlobal(g)); g = Astronomy.NextGlobalSolarEclipse(g.peak); } } else if (point) { const obs = new Astronomy.Observer(point.lat, point.lon, 0); let l = Astronomy.SearchLocalSolarEclipse(new Date(), obs); for (let i = 0; l && out.length < count && i < 200; i++) { if (l.peak.altitude > 0) out.push(normLocal(l)); l = Astronomy.NextLocalSolarEclipse(l.peak.time, obs); } } return out; }35:T59f,viewof earthFragmentShader = glsl( "earthFragmentShader", ` uniform sampler2D uDayTex; uniform sampler2D uNightTex; uniform vec3 uSunPos; uniform vec3 uMoonPos; varying vec2 vUv; varying vec3 vPos; ${obscurationGLSL} ${atmosphereGLSL} #define TAU_V vec3(0.055, 0.115, 0.245) void main() { vec3 n = normalize(vPos); vec3 sunDir = normalize(uSunPos - vPos); float ndl = max(dot(n, sunDir), 0.0); float obsc = moonObscuration(vPos); ndl = mix(ndl, 0.04, obsc); vec3 dayCol = texture2D(uDayTex, vUv).rgb; vec3 nightCol = texture2D(uNightTex, vUv).rgb; float s = dot(n, sunDir); float dayF = smoothstep(-0.08, 0.03, s); vec3 sunT = exp(-TAU_V * (1.0 / (ndl + 0.028))); float light = smoothstep(-0.1, 0.001, max(nightCol.r, nightCol.g) - nightCol.b); float nf = max(1.0 - dayF*sunT.z,0.0); nightCol *= 1.0 + light * (1.0-dayF*1.5); vec3 col = dayCol * sunT * dayF * (1.0 - obsc) + nightCol * nf; //float water = smoothstep(0.01,0.10,dayCol.b-max(dayCol.r,dayCol.g)); float mx = max(max(dayCol.r, dayCol.g), dayCol.b); float blueness = (dayCol.b - max(dayCol.r, dayCol.g))/max(mx,1e-4); float water = smoothstep(0.10, 0.30, blueness)*0.6+0.05; vec3 viewDir = normalize(cameraPosition - vPos); vec3 h = normalize(sunDir + viewDir); float spec = pow(max(dot(n, h), 0.0), 90.0); col += water * spec * vec3(1.0, 0.95, 0.85) * ndl * (1.0 - obsc); gl_FragColor = vec4(col,1); }` )36:T58b,viewof obscurationGLSL = glsl( "obscurationGLSL", ` const float PI = 3.141592653589793; const float R_SUN = 109.0757; const float R_MOON = 0.27247; float moonObscuration0(vec3 p) { vec3 toSun = uSunPos - p; vec3 toMoon = uMoonPos - p; float ds = length(toSun); float dm = length(toMoon); float alpha = asin(clamp(R_SUN / ds, 0.0, 1.0)); float beta = asin(clamp(R_MOON / dm, 0.0, 1.0)); float d = atan(length(cross(toSun, toMoon)), dot(toSun, toMoon)); if (d >= alpha + beta) return 0.0; if (beta > alpha && d <= beta - alpha) return 1.0; if (d < 1.0e-7) return clamp(beta*beta/(alpha*alpha), 0.0, 1.0); float d2 = d*d, a2 = alpha*alpha, b2 = beta*beta; float A = a2 * acos(clamp((d2 + a2 - b2) / (2.0*d*alpha), -1.0, 1.0)); float B = b2 * acos(clamp((d2 + b2 - a2) / (2.0*d*beta ), -1.0, 1.0)); float C = sqrt(max(0.0, (-d+alpha+beta)*(d+alpha-beta)*(d-alpha+beta)*(d+alpha+beta))); return clamp((A + B - 0.5*C) / (PI*a2), 0.0, 1.0); } uniform bool uRealShadows; float moonObscuration(vec3 p) { float a = moonObscuration0(p); if (uRealShadows) return a; else if (a>=1.0) return 1.0; //else if (a>0.0) return 0.5; else return floor(a*6.0)/6.0; } vec2 raySphere(vec3 ro, vec3 rd, float r) { float b = dot(ro, rd); float c = dot(ro, ro) - r*r; float disc = b*b - c; if (disc < 0.0) return vec2(-1.0); float s = sqrt(disc); return vec2(-b - s, -b + s); }` )37:Tf5f,viewof atmosphereGLSL = glsl( "atmosphereGLSL", ` #define R_EARTH 1.0 #define R_ATMO 1.0157 #define H_R 0.015 #define H_M 0.004 #define BETA_R vec3(3.8, 13.5, 33.1) #define BETA_M vec3(21) /* #define H_R 8.5/6371.0 #define H_M 1.2/6371.0 #define BETA_R vec3(5.802, 13.558, 33.100) * 1e-6 * 6.371e6 #define BETA_M vec3(3.996e-6 * 6.371e6) */ const float MIE_EX = 1.1; const float MIE_G = -0.78; float rayleighPhase(float cosT) { return 3.0 / (16.0 * PI) * (1.0 + cosT * cosT); } float miePhase(float g, float c, float cc) { float gg = g * g; float a = (1.0 - gg) * (1.0 + cc); float b = 1.0 + gg - 2.0 * g * c; b *= sqrt(b); b *= 2.0 + gg; return (3.0 / (8.0 * PI)) * a / b; } float densityRay(vec3 p) { return exp(-max(length(p) - R_EARTH, 0.0) / H_R); } float densityMie(vec3 p) { return exp(-max(length(p) - R_EARTH, 0.0) / H_M); } vec3 sunTransmittance(vec3 p, out float earthOcc, out vec3 sunDir, out float moonObsc) { vec3 toSun = uSunPos - p; sunDir = normalize(toSun); vec2 tESun = raySphere(p, sunDir, R_EARTH); earthOcc = (tESun.x > 0.0) ? 0.0 : 1.0; if (earthOcc < 0.5) return vec3(0.0); moonObsc = moonObscuration(p); vec2 tASun = raySphere(p, sunDir, R_ATMO); float chord = max(tASun.y, 0.0); vec3 pA = p + (chord * 0.25) * sunDir; vec3 pB = p + (chord * 0.75) * sunDir; float step = chord * 0.5; vec3 tau = (BETA_R * (densityRay(pA) + densityRay(pB)) + BETA_M * MIE_EX * (densityMie(pA) + densityMie(pB))) * step; return exp(-tau); } ${cloudsGLSL} vec3 sky(vec3 ro, vec3 rd) { vec2 tA = raySphere(ro, rd, R_ATMO); if (tA.x < 0.0) return vec3(0); float tStart = max(tA.x, 0.0); float tEnd = tA.y; vec2 tE = raySphere(ro, rd, R_EARTH); if (tE.x > 0.0) tEnd = min(tEnd, tE.x); if (tStart >= tEnd) return vec3(0); float tMid = (tStart + tEnd) * 0.5; float sliceLen = (tEnd - tStart) * 0.5; vec3 pFront = ro + ((tStart + tMid) * 0.5) * rd; vec3 pBack = ro + ((tMid + tEnd) * 0.5) * rd; vec3 sigmaRF = BETA_R * densityRay(pFront) * sliceLen; vec3 sigmaMF = BETA_M * densityMie(pFront) * sliceLen; vec3 sigmaRB = BETA_R * densityRay(pBack) * sliceLen; vec3 sigmaMB = BETA_M * densityMie(pBack) * sliceLen; vec3 sigmaF = sigmaRF + sigmaMF; vec3 sigmaB = sigmaRB + sigmaMB; float earthOccF, moonObscF; vec3 sunDirF; vec3 transSunF = sunTransmittance(pFront, earthOccF, sunDirF, moonObscF); float sunVisF = earthOccF * (1.0 - moonObscF); float earthOccB, moonObscB; vec3 sunDirB; vec3 transSunB = sunTransmittance(pBack, earthOccB, sunDirB, moonObscB); float sunVisB = earthOccB * (1.0 - moonObscB); float cF = dot(sunDirF, -rd); float cB = dot(sunDirB, -rd); float phaseR_F = rayleighPhase(cF); float phaseR_B = rayleighPhase(cB); float phaseM_F = miePhase(MIE_G, cF, cF * cF); float phaseM_B = miePhase(MIE_G, cB, cB * cB); vec3 L_front = sunVisF * transSunF * (phaseR_F * (1.0 - exp(-sigmaRF)) + phaseM_F * (1.0 - exp(-sigmaMF))); vec3 L_back = sunVisB * transSunB * exp(-sigmaF) * (phaseR_B * (1.0 - exp(-sigmaRB)) + phaseM_B * (1.0 - exp(-sigmaMB))); /*vec3 cloudCol = vec3(0); float cT = 1.0; vec2 tCo = raySphere(ro, rd, RC1); if (tCo.y > 0.0 && tCo.x < tEnd) { float cs = max(tCo.x, 0.0); float ce = tCo.y; vec2 tCi = raySphere(ro, rd, RC0); if (tCi.x > 0.0) ce = min(ce, tCi.x); if (tE.x > 0.0) ce = min(ce, tE.x); float span = ce - cs; if (span > 0.0) { float dt = span / 3.0; //float j = hash13(vec3(gl_FragCoord.xy, 7.31)) - 0.5; //cloudSample(ro + rd * (cs + dt * 0.5), rd, dt, cloudCol, cT); cloudSample(ro + rd * (cs + dt * 1.5), rd, dt, cloudCol, cT); //cloudSample(ro + rd * (cs + dt * 2.5), rd, dt, cloudCol, cT); } } vec3 airT = exp(-(sigmaF + sigmaB)); + airT * cloudCol*/ return (L_front + L_back) * 10.0; }` )38:Taf9,viewof cloudsGLSL = glsl( "cloudsGLSL", `#define iTime 0.0 #define RC0 1.012 #define RC1 1.040 #define CLOUD_EXT 25.0 #define SUN_TINT vec3(1.0, 0.97, 0.92) #define CLOUD_AMB vec3(0.22, 0.27, 0.36) float hash13(vec3 p3) { p3 = fract(p3 * 0.1031); p3 += dot(p3, p3.zyx + 31.32); return fract((p3.x + p3.y) * p3.z); } const float TAU = 6.2831853; const float SHAPE_POW = 6.0; const float SHAPE_MUL = 256.0; float hash12n(vec2 p) { vec3 p3 = fract(vec3(p.xyx) * 0.1031); p3 += dot(p3, p3.yzx + 33.33); return fract((p3.x + p3.y) * p3.z); } float vnoise2(vec2 p) { vec2 i = floor(p), f = fract(p); vec2 u = f * f * (3.0 - 2.0 * f); return mix(mix(hash12n(i), hash12n(i + vec2(1, 0)), u.x), mix(hash12n(i + vec2(0, 1)), hash12n(i + vec2(1, 1)), u.x), u.y); } const vec3 DRIFT = vec3(0.020, 0.007, -0.013) * iTime; const vec3 MORPH = vec3(0.009, -0.006, 0.011) * iTime; #define SWIRL_OCT(FQ) \ s += a * vnoise3(p * FQ * 0.5 + MORPH * a - DRIFT); \ m += a; a *= 0.6; \ p += vec3(cos(s * TAU), sin(s * TAU), cos(s * TAU * 1.31 + 2.17)) / ((FQ) * 2.0) * 0.4; float vnoise3(vec3 p) { vec3 i = floor(p), f = fract(p); vec3 u = f * f * (3.0 - 2.0 * f); return mix( mix(mix(hash13(i), hash13(i + vec3(1,0,0)), u.x), mix(hash13(i + vec3(0,1,0)), hash13(i + vec3(1,1,0)), u.x), u.y), mix(mix(hash13(i + vec3(0,0,1)), hash13(i + vec3(1,0,1)), u.x), mix(hash13(i + vec3(0,1,1)), hash13(i + vec3(1,1,1)), u.x), u.y), u.z); } float swirlyFbm(vec3 p) { float s = 0.0, m = 0.0, a = 1.0; SWIRL_OCT(5.0) SWIRL_OCT(10.0) SWIRL_OCT(20.0) SWIRL_OCT(40.0) SWIRL_OCT(80.0) SWIRL_OCT(160.0) return s / m; } float cloudCover(vec3 dir) { float c = swirlyFbm(normalize(dir)); return exp(-pow(c, SHAPE_POW) * SHAPE_MUL); } float cloudDensity(vec3 p) { float h = (length(p) - RC0) / (RC1 - RC0); if (h <= 0.0 || h >= 1.0) return 0.0; return smoothstep(0.0, 0.3, h) * smoothstep(1.0, 0.7, h) * cloudCover(normalize(p)); } float cloudShadow(vec3 p, vec3 sd) { float th = RC1 - RC0; float d1 = cloudDensity(p + sd * (th * 0.25)); float d2 = cloudDensity(p + sd * (th * 0.75)); return exp(-th * CLOUD_EXT * (d1 * 0.25 + d2 * 0.75)); } /*void cloudSample(vec3 P, vec3 rd, float w, inout vec3 col, inout float T) { float d = cloudDensity(P); if (d < 0.001) return; float occ; vec3 sd; float mo; vec3 st = sunTransmittance(P, occ, sd, mo); float c = dot(sd, -rd); float ph = 0.75 * miePhase(MIE_G, c, c * c) + 0.35; float pw = 1.0 - 0.75 * exp(-d * 4.0); vec3 lit = st * (occ * (1.0 - mo)) * cloudShadow(P, sd) * ph * pw; float sigma = d * CLOUD_EXT * w; col += T * (1.0 - exp(-sigma)) * (lit * SUN_TINT * 10.0 + CLOUD_AMB); T *= exp(-sigma); }*/` )39:T146e,Astro = { const AU_KM = 149597870.7; const ER_KM = 6378.137; const K = AU_KM / ER_KM; const R_SUN = 695700 / ER_KM; const R_MOON = 1737.4 / ER_KM; const RAD = Math.PI / 180; const clamp = (x, lo, hi) => Math.min(hi, Math.max(lo, x)); const sub3 = (a, b) => [a[0] - b[0], a[1] - b[1], a[2] - b[2]]; const add3 = (a, b) => [a[0] + b[0], a[1] + b[1], a[2] + b[2]]; const scale3 = (a, s) => [a[0] * s, a[1] * s, a[2] * s]; const dot3 = (a, b) => a[0] * b[0] + a[1] * b[1] + a[2] * b[2]; const cross3 = (a, b) => [ a[1] * b[2] - a[2] * b[1], a[2] * b[0] - a[0] * b[2], a[0] * b[1] - a[1] * b[0] ]; const len3 = (a) => Math.hypot(a[0], a[1], a[2]); const norm3 = (a) => scale3(a, 1 / len3(a)); function sunMoonScene(date) { const tm = Astronomy.MakeTime(date); const rot = Astronomy.Rotation_EQJ_EQD(tm); const g = Astronomy.SiderealTime(tm) * 15 * RAD; const cg = Math.cos(g), sg = Math.sin(g); const conv = (body) => { const v = Astronomy.RotateVector( rot, Astronomy.GeoVector(body, tm, true) ); const x = v.x * cg + v.y * sg; const y = -v.x * sg + v.y * cg; return [x * K, v.z * K, -y * K]; }; return { sun: conv(Astronomy.Body.Sun), moon: conv(Astronomy.Body.Moon) }; } const sceneToLatLon = (p) => ({ lat: Math.asin(clamp(p[1] / len3(p), -1, 1)) / RAD, lon: Math.atan2(-p[2], p[0]) / RAD }); const latLonToScene = (lat, lon) => { const c = Math.cos(lat * RAD); return [ c * Math.cos(lon * RAD), Math.sin(lat * RAD), -c * Math.sin(lon * RAD) ]; }; function shadowAxisHit(date) { const { sun, moon } = sunMoonScene(date); const u = norm3(sub3(moon, sun)); const b = dot3(moon, u); const c = dot3(moon, moon) - 1; const disc = b * b - c; if (disc < 0) return { hit: false, scene: [99999, 0, 0] }; const s = Math.sqrt(disc); const t = -b - s; if (t < 0) return { hit: false, scene: [99999, 0, 0] }; const p = add3(moon, scale3(u, t)); return { hit: true, scene: norm3(p) }; } function shadowAxisHit0(date,type) { const { sun, moon } = sunMoonScene(date); const u = norm3(sub3(moon, sun)); const tClosest = -dot3(moon, u); const pLine = add3(moon, scale3(u, tClosest)); const dist = len3(pLine); if (dist <= 1.0) { const tHit = tClosest - Math.sqrt(Math.max(0, 1 - dist * dist)); const pHit = add3(moon, scale3(u, tHit)); return { hit: true, scene: norm3(pHit), distance: 0 }; } else { const pMiss = norm3(pLine); return { hit: type=="partial", scene: pMiss }; } } function obscuration(p, sun, moon) { const toSun = sub3(sun, p), toMoon = sub3(moon, p); const ds = len3(toSun), dm = len3(toMoon); const alpha = Math.asin(clamp(R_SUN / ds, 0, 1)); const beta = Math.asin(clamp(R_MOON / dm, 0, 1)); const d = Math.atan2(len3(cross3(toSun, toMoon)), dot3(toSun, toMoon)); if (d >= alpha + beta) return 0; if (d <= beta - alpha) return 1; if (d < 1e-7) return clamp((beta * beta) / (alpha * alpha), 0, 1); const d2 = d * d, a2 = alpha * alpha, b2 = beta * beta; const A = a2 * Math.acos(clamp((d2 + a2 - b2) / (2 * d * alpha), -1, 1)); const B = b2 * Math.acos(clamp((d2 + b2 - a2) / (2 * d * beta), -1, 1)); const C = Math.sqrt( Math.max( 0, (-d + alpha + beta) * (d + alpha - beta) * (d - alpha + beta) * (d + alpha + beta) ) ); return clamp((A + B - 0.5 * C) / (Math.PI * a2), 0, 1); } const obscurationAtPoint = (point, date) => { const { sun, moon } = sunMoonScene(date); return obscuration(latLonToScene(point.lat, point.lon), sun, moon); }; const sunAltitude = (point, date) => { const obs = new Astronomy.Observer(point.lat, point.lon, 0); const tm = Astronomy.MakeTime(date); const eq = Astronomy.Equator(Astronomy.Body.Sun, tm, obs, true, true); return Astronomy.Horizon(tm, obs, eq.ra, eq.dec, "normal").altitude; }; const toDate = (x) => (x instanceof Date ? x : x.date); const addH = (t, h) => new Date(toDate(t).getTime() + h * 3600e3); const scrubDate = (ecl, s) => { const a = toDate(ecl.window.start).getTime(), b = toDate(ecl.window.end).getTime(); return new Date(a + (b - a) * s); }; const fmtUTC = (t) => toDate(t).toISOString().replace("T", " ").slice(0, 16) + " UTC"; const fmtDate = (t) => toDate(t).toISOString().slice(0, 10); const fmtTime = (t) => toDate(t).toISOString().slice(11, 16); const fmtLatLon = (p) => `${Math.abs(p.lat).toFixed(2)}°${p.lat >= 0 ? "N" : "S"}, ${Math.abs( p.lon ).toFixed(2)}°${p.lon >= 0 ? "E" : "W"}`; const fmtDur = (s) => s == null ? "-" : `${Math.floor(s / 60)}m${Math.round(s % 60) .toString() .padStart(2, "0")}s`; return { sunMoonScene, sceneToLatLon, latLonToScene, shadowAxisHit, obscuration, obscurationAtPoint, sunAltitude, toDate, addH, scrubDate, fmtUTC, fmtDate, fmtTime, fmtLatLon, fmtDur }; }3a:[] 2f:{"id":"78781bf1e5576566","slug":"eclipses","title":"Eclipses","thumbnail":"111d7be01cf3a7ccb4ba78529fb00e653465773aeb6d883d4ed135173b724e62","access_level":"public","create_time":"$D2026-08-25T17:38:36.711Z","update_time":"$D2026-09-05T08:04:40.408Z","view_time":null,"first_public_time":"$D2026-08-26T04:40:59.316Z","fork":false,"stars":8,"starred":false,"owner":{"type":"team","id":"d6840fab65eebcab","login":"nxrix","name":"nxrix","avatar_url":"https://avatars-next.observableusercontent.com/e64bf55bfe8edb531a8042147a84d2906d224f9102c11c06b67fae3be08b1a80","tier":"starter_2024"},"version":578,"publish_version":null,"role":null,"authored":false,"authors":[{"type":"individual","id":"9d8e4bfddc4592ef","login":"nxrix","name":"nxrix","avatar_url":"https://avatars-next.observableusercontent.com/e64bf55bfe8edb531a8042147a84d2906d224f9102c11c06b67fae3be08b1a80","tier":null}],"members":[{"type":"individual","id":"9d8e4bfddc4592ef","login":"nxrix","name":"nxrix","avatar_url":"https://avatars-next.observableusercontent.com/e64bf55bfe8edb531a8042147a84d2906d224f9102c11c06b67fae3be08b1a80","tier":null,"role":"editor"},{"type":"team","id":"d6840fab65eebcab","login":"nxrix","name":"nxrix","avatar_url":"https://avatars-next.observableusercontent.com/e64bf55bfe8edb531a8042147a84d2906d224f9102c11c06b67fae3be08b1a80","tier":"starter_2024","role":"editor"}],"comments":[],"custom_thumbnail":false,"trashed":false,"subscribed":null,"forks":3,"collection":null,"type":"notebook","body":{"title":"Eclipses","cells":[{"id":0,"value":"# Eclipses","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined"},{"id":49,"value":"canvas = renderer.domElement","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":159,"value":"{\n const i = Inputs.number({\n placeholder: \"Size\",\n value: 1024,\n min: 1,\n step: 1\n });\n const d = Inputs.button(\"Download PNG\", {\n reduce() {\n const a = document.createElement(\"a\");\n const s = Number(i.value) || 1024;\n renderer.resize(s, (s * 3) / 4, 1);\n a.href = canvas.toDataURL();\n renderer.resizeEvent();\n a.download = `image.png`;\n a.click();\n }\n });\n i.style.width = \"100px\";\n return html`

${i}${d}

`;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":80,"value":"{\n const e = Inputs.toggle({ label: \"Real Shadows\", value: true });\n e.addEventListener(\"input\", () => {\n renderer.api.setRealShadows(e.value);\n });\n return e;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":83,"value":"viewof progress = Inputs.range([0, 1], {\n label: \"Eclipse progress\",\n step: 0.001,\n value: 0\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":86,"value":"{\n const ecl = selectedEclipse;\n if (!ecl) return html`

Select an eclipse.

`;\n const t = Astro.scrubDate(ecl, progress);\n const rows = [\n html`

🕰 ${Astro.fmtUTC(t)}

`,\n html`

Window: ${Astro.fmtUTC(\n ecl.window.start\n )} to ${Astro.fmtUTC(ecl.window.end)}

`\n ];\n if (ecl.mode === \"Local\")\n rows.push(\n html`

Max obscuration ${(100 * ecl.obscuration).toFixed(\n 1\n )}% | Peak Sun altitude ${ecl.peakAltitude.toFixed(0)}°${\n ecl.centralDuration != null\n ? html` | Central phase ${Astro.fmtDur(ecl.centralDuration)}`\n : \"\"\n }

`\n );\n if (marker)\n rows.push(\n html`

At your marker (${Astro.fmtLatLon(marker)}): Obscuration ${(\n 100 * Astro.obscurationAtPoint(marker, t)\n ).toFixed(1)}% | Sun altitude ${Astro.sunAltitude(\n marker,\n t\n ).toFixed(1)}°

`\n );\n return html`

${rows}

`;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":94,"value":"viewof mode = Inputs.radio([\"Global\", \"Local\"], {\n value: \"Global\",\n label: \"Eclipse Type\"\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":91,"value":"viewof count = Inputs.select([2, 4, 6, 8, 10], {\n value: 4,\n label: \"Count\",\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":97,"value":"viewof eclipseList = {\n if (mode === \"Local\" && !marker) {\n const e = md`Click a point on the globe to search eclipses visible from there.`;\n e.value = [];\n return e;\n }\n const t0 = performance.now();\n const list = searchEclipses(mode, marker, count);\n const e = md`Found **${list.length}** ${mode.toLowerCase()} solar eclipse${\n list.length === 1 ? \"\" : \"s\"\n } in ${(performance.now() - t0).toFixed(0)} ms.`;\n e.value = list;\n return e;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":101,"value":"$31","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":245,"value":"$32","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":45,"value":"---","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined"},{"id":397,"value":"errors = html`

Loading...

`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":107,"value":"updateScene = {\n const api = renderer.api;\n if (!api) return;\n const ecl = selectedEclipse;\n if (ecl) {\n api.setBodies(Astro.sunMoonScene(Astro.scrubDate(ecl, progress)));\n api.setTrail(trailPoints(ecl));\n } else {\n api.setBodies(null);\n api.setTrail(null);\n }\n return \"\";\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":302,"value":"state = {\n return {\n selectedEclipse: null\n };\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":66,"value":"mutable marker = null","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":8,"value":"$33","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":42,"value":"trailPoints = {\n const cache = new Map();\n return (ecl, n = 256) => {\n if (!ecl) return null;\n const key = `${ecl.key}|${ecl.window.start}|${ecl.window.end}|${n}`;\n if (cache.has(key)) return cache.get(key);\n const a = Astro.toDate(ecl.window.start).getTime();\n const b = Astro.toDate(ecl.window.end).getTime();\n const pts = [];\n for (let i = 0; i <= n; i++) {\n const t = a + ((b - a) * i) / n;\n const r = Astro.shadowAxisHit(new Date(t),ecl.kind);\n if (!r.hit || !r.scene) continue;\n const p = r.scene;\n if (!p.every(Number.isFinite)) continue;\n pts.push([p[0] * 1.004, p[1] * 1.004, p[2] * 1.004]);\n }\n cache.set(key, pts);\n return pts;\n };\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":38,"value":"$34","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":35,"value":"viewof atmoFragmentShader = glsl(\n \"atmoFragmentShader\",\n `\nprecision highp float;\n\nuniform vec3 uSunPos;\nuniform vec3 uMoonPos;\nvarying vec3 vPos;\n\n${obscurationGLSL}\n${atmosphereGLSL}\n\nvoid main() {\n vec3 ro = cameraPosition;\n vec3 rd = normalize(vPos - ro);\n gl_FragColor = vec4(sky(ro,rd), 1);\n}`\n)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":32,"value":"viewof atmoVertexShader = glsl(\n \"atmoVertexShader\",\n `\nvarying vec3 vPos;\nvoid main() {\n vPos = position;\n gl_Position = projectionMatrix*modelViewMatrix*vec4(position,1);\n}`\n)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":29,"value":"$35","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":26,"value":"viewof earthVertexShader = glsl(\n \"earthVertexShader\",\n `\nvarying vec2 vUv;\nvarying vec3 vPos;\nvoid main() {\n vUv = uv;\n vPos = position;\n gl_Position = projectionMatrix*modelViewMatrix*vec4(position,1);\n}`\n)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":23,"value":"$36","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":395,"value":"$37","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":366,"value":"$38","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":20,"value":"textures = {\n const loader = new THREE.TextureLoader();\n const load = (url) =>\n new Promise((resolve, reject) => {\n loader.load(url, resolve, undefined, reject);\n });\n const u = [\n \"https://cdn.jsdelivr.net/npm/three-globe/example/img/earth-blue-marble.jpg\",\n \"https://cdn.jsdelivr.net/npm/three-globe/example/img/earth-night.jpg\"\n ];\n // https://www.solarsystemscope.com/textures/download/8k_earth_daymap.jpg\n // https://www.solarsystemscope.com/textures/download/8k_earth_nightmap.jpg\n // https://cdn.jsdelivr.net/gh/mrdoob/three.js@r171/examples/textures/planets/earth_day_4096.jpg\n // https://cdn.jsdelivr.net/gh/mrdoob/three.js@r171/examples/textures/planets/earth_night_4096.jpg\n // https://cdn.jsdelivr.net/gh/mrdoob/three.js@r171/examples/textures/planets/earth_specular_2048.jpg\n const [day, night] = await Promise.all([load(u[0]), load(u[1])]);\n return { day, night };\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":17,"value":"glsl = (l = \"\", t) => {\n return Object.assign(md`\\`${l} = glsl(~)\\``, { value: t });\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":14,"value":"$39","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":11,"value":"Astronomy = import(\"astronomy-engine\")","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"},{"id":5,"value":"THREE = {\n try {\n const THREE = await import(\"three@0.184.0\");\n const { OrbitControls } = await import(\n \"three@0.184.0/examples/jsm/controls/OrbitControls.js\"\n );\n return { ...THREE, OrbitControls };\n } catch (e) {\n // IOS 15 issue\n const THREE = await import(\"https://esm.sh/three@0.184.0?target=es2020\");\n const { OrbitControls } = await import(\n \"https://esm.sh/three@0.184.0/examples/jsm/controls/OrbitControls.js?target=es2020\"\n );\n return { ...THREE, OrbitControls };\n }\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined"}],"files":"$W3a","stdlib":"2","titling":"auto"}} 30:"$2f:body"