9b20040b49
The background weather is now GPU-rendered: one instanced-quad draw call over a baked sprite atlas plus a fullscreen sky shader (fog, Saharan haze, aurora, sun rays, storm gloom and lightning flash). The old Canvas2D renderer stays as weather-2d.js and kicks in automatically when WebGL2 is missing; weather.js is now a thin controller that owns the toggle, prefs and the PeteWeather API. Effect upgrades: shared wind with gust pulses leans the whole scene together, rain gets depth, splash pops and velocity-aligned streaks, storms grow procedural branched lightning bolts, snow mixes soft motes with spinning six-arm crystals, clouds drift in two parallax layers, clear nights get a moon with maria, twinkling stars and the occasional shooting star, blossoms and leaves tumble with a faked 3D flip. New variants: haze (Saharan calima), wind (autumn gusts with streak lines), hail (bouncing stones with drizzle) and aurora. The /weather demo page switches variant, intensity and phase in place without a reload and shows the active renderer plus an FPS meter.
488 lines
18 KiB
JavaScript
488 lines
18 KiB
JavaScript
// Canvas2D weather engine — the fallback when WebGL2 isn't available. This is
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// the original hand-drawn renderer wrapped as an engine factory; weather.js
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// owns the toggle, storage and the PeteWeather API and just calls
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// set/start/stop here. New GPU-only variants (hail, haze, wind, aurora) alias
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// to their nearest 2D look so the fallback never renders a blank page.
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(function () {
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window.PeteWeatherEngines = window.PeteWeatherEngines || {};
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window.PeteWeatherEngines.canvas2d = function (canvas) {
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var ctx = canvas.getContext("2d");
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if (!ctx) return null;
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var root = document.documentElement;
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var W = 0, H = 0, DPR = 1;
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function resize() {
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DPR = Math.min(window.devicePixelRatio || 1, 2);
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W = canvas.clientWidth || window.innerWidth;
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H = canvas.clientHeight || window.innerHeight;
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canvas.width = Math.floor(W * DPR);
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canvas.height = Math.floor(H * DPR);
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ctx.setTransform(DPR, 0, 0, DPR, 0, 0);
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}
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resize();
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window.addEventListener("resize", resize);
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var aliases = { hail: "snow", haze: "motes", wind: "leaves", aurora: "clear" };
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var counts = {
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rain: 160, petals: 50, jacaranda: 55, motes: 70, leaves: 38,
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snow: 150, clouds: 7, fog: 7, clear: 0, storm: 200
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};
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var mults = { light: 0.6, medium: 1.0, heavy: 1.4 };
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function rand(a, b) { return a + Math.random() * (b - a); }
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var variant = null; // current rendered variant
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var intensity = "heavy"; // light | medium | heavy
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var particles = [];
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var flash = 0; // lightning flash decay (storm only)
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var nextBolt = 2; // seconds until next lightning bolt (storm only)
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function spawn(initial) {
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var p = {};
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p.x = rand(0, W);
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p.y = initial ? rand(0, H) : rand(-40, -10);
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p.z = rand(0.7, 1.3); // depth — affects size + speed + alpha
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if (variant === "rain" || variant === "storm") {
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p.vy = rand(700, 1100) * p.z;
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p.vx = -rand(60, 120);
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p.len = rand(10, 18) * p.z;
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p.alpha = rand(0.25, 0.55);
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} else if (variant === "snow") {
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p.vy = rand(35, 75) * p.z;
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p.swayAmp = rand(12, 34);
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p.swayFreq = rand(0.3, 0.8);
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p.swayPhase = rand(0, Math.PI * 2);
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p.size = rand(2, 4.6) * p.z;
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p.alpha = rand(0.65, 0.95);
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} else if (variant === "clouds") {
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// Soft puffs drifting across the upper sky.
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p.y = initial ? rand(0, H * 0.5) : rand(-H * 0.1, H * 0.45);
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p.x = initial ? rand(0, W) : -rand(120, 320);
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p.vx = rand(8, 22);
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p.size = rand(80, 170) * p.z;
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p.alpha = rand(0.32, 0.55);
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p.sprite = Math.floor(rand(0, 3));
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} else if (variant === "fog") {
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// Wide translucent bands creeping sideways.
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p.y = rand(H * 0.1, H);
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p.x = initial ? rand(0, W) : -rand(200, 500);
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p.vx = rand(6, 16);
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p.w = rand(260, 520);
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p.h = rand(70, 150);
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p.alpha = rand(0.05, 0.14);
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} else if (variant === "petals" || variant === "jacaranda") {
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p.vy = rand(60, 120);
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p.swayAmp = rand(20, 50);
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p.swayFreq = rand(0.4, 0.9);
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p.swayPhase = rand(0, Math.PI * 2);
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p.rot = rand(0, Math.PI * 2);
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p.vrot = rand(-1.2, 1.2);
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p.size = rand(8, 16) * p.z;
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p.alpha = rand(0.75, 1.0);
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if (variant === "jacaranda") {
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p.hue = rand(265, 285); // blue-violet — jacaranda uses the petal silhouette in purple
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p.sat = rand(55, 75);
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p.light = rand(70, 82);
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} else {
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p.hue = rand(335, 355); // pink (almond/cherry)
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p.sat = rand(60, 80);
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p.light = rand(78, 88);
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}
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} else if (variant === "motes") {
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p.vx = rand(-15, 25);
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p.vy = rand(8, 25);
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p.size = rand(1.2, 2.8) * p.z;
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p.alpha = rand(0.35, 0.7);
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p.twinklePhase = rand(0, Math.PI * 2);
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p.twinkleFreq = rand(0.5, 1.5);
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} else if (variant === "leaves") {
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p.vy = rand(70, 130);
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p.swayAmp = rand(30, 70);
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p.swayFreq = rand(0.3, 0.6);
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p.swayPhase = rand(0, Math.PI * 2);
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p.rot = rand(0, Math.PI * 2);
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p.vrot = rand(-2.0, 2.0);
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p.size = rand(10, 18) * p.z;
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p.alpha = rand(0.8, 1.0);
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p.hue = rand(18, 42); // orange→amber→brown
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p.light = rand(38, 55);
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}
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return p;
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}
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var night = root.dataset.phase === "night";
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function refreshNight() { night = root.dataset.phase === "night"; }
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function drawRain(p) {
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// Day/dawn/dusk backgrounds are warm and pale, so the rain needs a darker,
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// more saturated blue plus a slightly thicker line to stay visible. Night
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// keeps a paler tone so streaks read against the dark palette.
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if (night) {
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ctx.strokeStyle = "rgba(200,215,240," + p.alpha + ")";
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ctx.lineWidth = 1;
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} else {
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ctx.strokeStyle = "rgba(60,95,150," + Math.min(1, p.alpha + 0.25) + ")";
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ctx.lineWidth = 1.3;
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}
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ctx.beginPath();
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ctx.moveTo(p.x, p.y);
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ctx.lineTo(p.x - p.len * 0.12, p.y + p.len);
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ctx.stroke();
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}
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function drawSnow(p) {
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// Soft round flake with a faint glow so it reads on light and dark palettes.
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var col = night ? "235,242,255" : "255,255,255";
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ctx.fillStyle = "rgba(" + col + "," + p.alpha + ")";
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ctx.beginPath();
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ctx.arc(p.x, p.y, p.size, 0, Math.PI * 2);
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ctx.fill();
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if (!night) {
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// A thin cool outline keeps white flakes visible against cream backgrounds.
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ctx.strokeStyle = "rgba(150,180,220," + (p.alpha * 0.5) + ")";
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ctx.lineWidth = 0.6;
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ctx.stroke();
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}
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}
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// Pre-baked cloud sprites: clustered blobs softened with a heavy blur so each
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// cloud reads as one fluffy mass. Built once per palette (day/night) onto
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// offscreen canvases, then just drifted — cheap to animate.
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var cloudSprites = null;
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var cloudSpritesNight = null;
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// Three silhouettes for variety. Each is a list of blobs [cx, cy, r] in a
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// 0..1 box (x across, y down) with a flattish base around y≈0.66.
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var cloudShapes = [
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[[0.50, 0.50, 0.26], [0.34, 0.56, 0.20], [0.66, 0.56, 0.20], [0.42, 0.40, 0.18],
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[0.58, 0.38, 0.17], [0.22, 0.60, 0.15], [0.78, 0.60, 0.15], [0.50, 0.62, 0.22]],
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[[0.46, 0.52, 0.24], [0.30, 0.58, 0.18], [0.62, 0.50, 0.22], [0.74, 0.58, 0.16],
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[0.40, 0.40, 0.16], [0.56, 0.36, 0.15], [0.18, 0.62, 0.13], [0.84, 0.62, 0.12]],
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[[0.52, 0.50, 0.28], [0.36, 0.56, 0.19], [0.68, 0.56, 0.18], [0.48, 0.36, 0.16],
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[0.26, 0.60, 0.14], [0.74, 0.60, 0.15], [0.60, 0.62, 0.18], [0.40, 0.62, 0.18]]
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];
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function makeCloudSprite(col, shape) {
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var c = document.createElement("canvas");
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var w = 320, h = 224;
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c.width = w; c.height = h;
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var cx = c.getContext("2d");
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cx.filter = "blur(18px)"; // the softness that turns blobs into a cloud
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cx.fillStyle = "rgba(" + col + ",1)";
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for (var i = 0; i < shape.length; i++) {
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cx.beginPath();
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cx.arc(shape[i][0] * w, shape[i][1] * h, shape[i][2] * w, 0, Math.PI * 2);
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cx.fill();
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}
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return c;
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}
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function ensureCloudSprites() {
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if (cloudSprites && cloudSpritesNight === night) return;
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// Day sky is warm cream so clouds need a cool slate-grey; night uses a pale
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// tone against the dark palette.
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var col = night ? "206,216,236" : "150,164,190";
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cloudSprites = cloudShapes.map(function (s) { return makeCloudSprite(col, s); });
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cloudSpritesNight = night;
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}
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function drawCloud(p) {
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ensureCloudSprites();
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var spr = cloudSprites[p.sprite % cloudSprites.length];
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var w = p.size * 2.6;
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var h = w * (spr.height / spr.width);
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ctx.globalAlpha = p.alpha;
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ctx.drawImage(spr, p.x - w / 2, p.y - h / 2, w, h);
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ctx.globalAlpha = 1;
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}
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function drawFog(p) {
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var col = night ? "150,160,180" : "230,228,224";
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var g = ctx.createLinearGradient(p.x - p.w / 2, 0, p.x + p.w / 2, 0);
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g.addColorStop(0, "rgba(" + col + ",0)");
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g.addColorStop(0.5, "rgba(" + col + "," + p.alpha + ")");
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g.addColorStop(1, "rgba(" + col + ",0)");
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ctx.fillStyle = g;
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ctx.beginPath();
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ctx.ellipse(p.x, p.y, p.w / 2, p.h / 2, 0, 0, Math.PI * 2);
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ctx.fill();
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}
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function drawMoon(cx, cy, mr) {
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var TAU = Math.PI * 2;
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ctx.save();
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// Clip everything to the lunar disc so shading stays inside the sphere.
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ctx.beginPath();
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ctx.arc(cx, cy, mr, 0, TAU);
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ctx.clip();
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// Spherical body shading — light source upper-right, terminator lower-left.
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var lx = cx + mr * 0.45, ly = cy - mr * 0.45;
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var body = ctx.createRadialGradient(lx, ly, mr * 0.1, cx, cy, mr * 1.35);
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body.addColorStop(0, "rgba(249,251,255,0.97)");
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body.addColorStop(0.55, "rgba(214,222,240,0.92)");
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body.addColorStop(1, "rgba(140,151,180,0.85)");
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ctx.fillStyle = body;
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ctx.fillRect(cx - mr, cy - mr, mr * 2, mr * 2);
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// Limb darkening — fade the edge so the disc reads as a ball, not a coin.
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var limb = ctx.createRadialGradient(cx, cy, mr * 0.62, cx, cy, mr);
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limb.addColorStop(0, "rgba(18,24,46,0)");
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limb.addColorStop(1, "rgba(18,24,46,0.4)");
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ctx.fillStyle = limb;
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ctx.fillRect(cx - mr, cy - mr, mr * 2, mr * 2);
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ctx.restore();
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// Soft outer halo, drawn unclipped around the disc.
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var halo = ctx.createRadialGradient(cx, cy, mr, cx, cy, mr * 2.4);
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halo.addColorStop(0, "rgba(220,230,255,0.28)");
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halo.addColorStop(1, "rgba(220,230,255,0)");
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ctx.fillStyle = halo;
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ctx.beginPath();
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ctx.arc(cx, cy, mr * 2.4, 0, TAU);
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ctx.fill();
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}
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function drawClearGlow(t) {
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// No particles — render a single calm sun (day) or moon (night) glow that
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// breathes very slowly, plus a few stars at night.
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var breathe = 0.5 + 0.5 * Math.sin(t * 0.25);
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var cx = W * 0.82, cy = H * 0.18, r = Math.min(W, H) * 0.5;
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if (night) {
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// Ambient sky glow around the moon.
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var g = ctx.createRadialGradient(cx, cy, 0, cx, cy, r);
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g.addColorStop(0, "rgba(220,230,255," + (0.12 + 0.05 * breathe) + ")");
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g.addColorStop(1, "rgba(220,230,255,0)");
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ctx.fillStyle = g;
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ctx.fillRect(0, 0, W, H);
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drawMoon(cx, cy, r * 0.16);
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} else {
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var gd = ctx.createRadialGradient(cx, cy, 0, cx, cy, r);
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gd.addColorStop(0, "rgba(255,224,150," + (0.30 + 0.10 * breathe) + ")");
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gd.addColorStop(0.5, "rgba(255,214,120," + (0.10 + 0.04 * breathe) + ")");
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gd.addColorStop(1, "rgba(255,214,120,0)");
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ctx.fillStyle = gd;
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ctx.fillRect(0, 0, W, H);
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}
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}
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// Deterministic star field for clear nights (seeded so they don't jitter).
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var stars = [];
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function buildStars() {
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stars = [];
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var n = 60;
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for (var i = 0; i < n; i++) {
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// Cheap LCG-ish spread keyed by index — stable across frames.
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var sx = ((i * 73 + 11) % 100) / 100;
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var sy = ((i * 37 + 7) % 100) / 100;
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stars.push({ x: sx, y: sy * 0.7, r: 0.6 + (i % 3) * 0.5, ph: (i % 7) });
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}
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}
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function drawStars(t) {
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for (var i = 0; i < stars.length; i++) {
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var s = stars[i];
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var tw = 0.4 + 0.6 * (0.5 + 0.5 * Math.sin(t * 0.8 + s.ph));
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ctx.fillStyle = "rgba(255,255,255," + (0.5 * tw) + ")";
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ctx.beginPath();
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ctx.arc(s.x * W, s.y * H, s.r, 0, Math.PI * 2);
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ctx.fill();
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}
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}
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function drawPetals(p) {
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// Five-petal almond/cherry blossom viewed face-on, with a yellow center.
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var s = p.size;
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ctx.save();
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ctx.translate(p.x, p.y);
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ctx.rotate(p.rot);
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ctx.fillStyle = "hsla(" + p.hue + "," + p.sat + "%," + p.light + "%," + p.alpha + ")";
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for (var i = 0; i < 5; i++) {
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var a = (i / 5) * Math.PI * 2 - Math.PI / 2;
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var cx = Math.cos(a) * s * 0.32;
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var cy = Math.sin(a) * s * 0.32;
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ctx.beginPath();
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ctx.ellipse(cx, cy, s * 0.38, s * 0.24, a, 0, Math.PI * 2);
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ctx.fill();
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}
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ctx.fillStyle = "hsla(48,90%,68%," + p.alpha + ")";
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ctx.beginPath();
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ctx.arc(0, 0, s * 0.13, 0, Math.PI * 2);
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ctx.fill();
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ctx.restore();
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}
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function drawLeaf(p) {
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var s = p.size;
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ctx.save();
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ctx.translate(p.x, p.y);
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ctx.rotate(p.rot);
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var g = ctx.createLinearGradient(-s * 0.5, 0, s * 0.5, 0);
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g.addColorStop(0, "hsla(" + p.hue + ",70%," + (p.light - 10) + "%," + p.alpha + ")");
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g.addColorStop(1, "hsla(" + p.hue + ",75%," + (p.light + 10) + "%," + p.alpha + ")");
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ctx.fillStyle = g;
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// Almond/lozenge leaf — pointed at both ends.
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ctx.beginPath();
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ctx.moveTo(-s * 0.55, 0);
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ctx.quadraticCurveTo(0, -s * 0.38, s * 0.55, 0);
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ctx.quadraticCurveTo(0, s * 0.38, -s * 0.55, 0);
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ctx.closePath();
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ctx.fill();
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// Midrib vein.
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ctx.strokeStyle = "hsla(" + p.hue + ",60%," + (p.light - 22) + "%," + (p.alpha * 0.7) + ")";
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ctx.lineWidth = 0.8;
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ctx.beginPath();
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ctx.moveTo(-s * 0.5, 0);
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ctx.lineTo(s * 0.5, 0);
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ctx.stroke();
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// Small stem nub at the base.
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ctx.strokeStyle = "hsla(" + p.hue + ",55%," + (p.light - 25) + "%," + (p.alpha * 0.7) + ")";
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ctx.lineWidth = 1.0;
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ctx.beginPath();
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ctx.moveTo(-s * 0.55, 0);
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ctx.lineTo(-s * 0.7, -s * 0.04);
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ctx.stroke();
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ctx.restore();
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}
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function drawMote(p, t) {
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var twinkle = 0.5 + 0.5 * Math.sin(t * p.twinkleFreq + p.twinklePhase);
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// Night keeps a pale glowing mote against the dark palette. Day/dawn/dusk
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// use a deeper saturated honey so the motes stand out against warm cream
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// and peach backgrounds; alpha also gets a bump.
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var color, a;
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if (night) {
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color = "255,240,180";
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a = p.alpha * (0.45 + 0.55 * twinkle);
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} else {
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color = "130,80,180";
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a = Math.min(1, (p.alpha + 0.2) * (0.6 + 0.4 * twinkle));
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}
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// Soft glow halo.
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var g = ctx.createRadialGradient(p.x, p.y, 0, p.x, p.y, p.size * 5);
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g.addColorStop(0, "rgba(" + color + "," + (a * 0.55) + ")");
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g.addColorStop(1, "rgba(" + color + ",0)");
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ctx.fillStyle = g;
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ctx.beginPath();
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ctx.arc(p.x, p.y, p.size * 5, 0, Math.PI * 2);
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ctx.fill();
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// Bright core.
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ctx.fillStyle = "rgba(" + color + "," + a + ")";
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ctx.beginPath();
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ctx.arc(p.x, p.y, p.size, 0, Math.PI * 2);
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ctx.fill();
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}
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var last = performance.now();
|
|
var raf = 0;
|
|
|
|
function step(now) {
|
|
var dt = Math.min(0.05, (now - last) / 1000);
|
|
last = now;
|
|
var t = now / 1000;
|
|
ctx.clearRect(0, 0, W, H);
|
|
refreshNight();
|
|
|
|
if (variant === "clear") {
|
|
drawClearGlow(t);
|
|
if (night) drawStars(t);
|
|
raf = requestAnimationFrame(step);
|
|
return;
|
|
}
|
|
|
|
// Storm: drive the lightning flash before drawing rain over it.
|
|
if (variant === "storm") {
|
|
nextBolt -= dt;
|
|
if (nextBolt <= 0) {
|
|
flash = 1;
|
|
nextBolt = rand(2.5, 7);
|
|
}
|
|
if (flash > 0) {
|
|
ctx.fillStyle = "rgba(235,240,255," + (flash * 0.5) + ")";
|
|
ctx.fillRect(0, 0, W, H);
|
|
flash = Math.max(0, flash - dt * 4); // ~0.25s decay
|
|
}
|
|
}
|
|
|
|
for (var i = 0; i < particles.length; i++) {
|
|
var p = particles[i];
|
|
if (variant === "rain" || variant === "storm") {
|
|
p.x += p.vx * dt;
|
|
p.y += p.vy * dt;
|
|
if (p.y > H + 20 || p.x < -40) {
|
|
particles[i] = spawn(false);
|
|
particles[i].x = rand(0, W + 60);
|
|
continue;
|
|
}
|
|
drawRain(p);
|
|
} else if (variant === "snow") {
|
|
p.y += p.vy * dt;
|
|
var sxOff = Math.sin(t * p.swayFreq + p.swayPhase) * p.swayAmp;
|
|
if (p.y > H + 10) { particles[i] = spawn(false); continue; }
|
|
var ox = p.x; p.x = ox + sxOff;
|
|
drawSnow(p);
|
|
p.x = ox;
|
|
} else if (variant === "clouds") {
|
|
p.x += p.vx * dt;
|
|
if (p.x - p.size * 1.3 > W + 40) { particles[i] = spawn(false); continue; }
|
|
drawCloud(p);
|
|
} else if (variant === "fog") {
|
|
p.x += p.vx * dt;
|
|
if (p.x - p.w / 2 > W + 40) { particles[i] = spawn(false); continue; }
|
|
drawFog(p);
|
|
} else if (variant === "motes") {
|
|
p.x += p.vx * dt;
|
|
p.y += p.vy * dt;
|
|
if (p.y > H + 10 || p.x < -10 || p.x > W + 10) {
|
|
particles[i] = spawn(false);
|
|
continue;
|
|
}
|
|
drawMote(p, t);
|
|
} else {
|
|
// Drifting variants: petals, jacaranda, leaves.
|
|
p.y += p.vy * dt;
|
|
p.rot += p.vrot * dt;
|
|
var sway = Math.sin(t * p.swayFreq + p.swayPhase) * p.swayAmp;
|
|
var origX = p.x;
|
|
p.x = origX + sway;
|
|
if (p.y > H + 30) {
|
|
particles[i] = spawn(false);
|
|
continue;
|
|
}
|
|
if (variant === "jacaranda" || variant === "petals") drawPetals(p);
|
|
else drawLeaf(p);
|
|
p.x = origX;
|
|
}
|
|
}
|
|
raf = requestAnimationFrame(step);
|
|
}
|
|
|
|
function start() {
|
|
if (raf) return;
|
|
last = performance.now();
|
|
raf = requestAnimationFrame(step);
|
|
}
|
|
function stop() {
|
|
if (raf) cancelAnimationFrame(raf);
|
|
raf = 0;
|
|
ctx.clearRect(0, 0, W, H);
|
|
}
|
|
|
|
// Build the particle pool for a variant. The controller decides whether to
|
|
// start rendering afterwards.
|
|
function set(v, inten) {
|
|
variant = aliases[v] || v || null;
|
|
intensity = inten || "heavy";
|
|
flash = 0; nextBolt = rand(1.5, 4);
|
|
particles = [];
|
|
if (variant === "clear") { buildStars(); }
|
|
if (!variant) { stop(); return; }
|
|
var N = Math.round((counts[variant] || 0) * (mults[intensity] || 1));
|
|
for (var i = 0; i < N; i++) particles.push(spawn(true));
|
|
}
|
|
|
|
return { name: "canvas2d", set: set, start: start, stop: stop };
|
|
};
|
|
})();
|