80 lines
1.8 KiB
JavaScript
80 lines
1.8 KiB
JavaScript
// Clouds.js
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// Biased random
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function randomGaussian(A, B, biasFactor=2) {
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let u = Math.random();
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let v = Math.random();
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let num = Math.sqrt(-2.0 * Math.log(u)) * Math.cos(2.0 * Math.PI * v);
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let mean = (A + B) / 2;
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let stdDev = (B - A) / biasFactor;
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let result = mean + num * stdDev;
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return Math.min(Math.max(result, A), B);
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}
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// Spawn clouds
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var clouds = [];
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setTimeout(() => {
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for (var i = 0;i < 50;i++) {
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var w = (Math.random() * 11) + 6;
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var h = (Math.random() * 7) + 3;
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// Higher clouds = faster
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var y = randomGaussian(0, height * 0.75, 5);
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var speedFactor = (1 - (y / (height * 0.75)));
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clouds.push({
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x: Math.random() * (width - w),
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y: y,
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w: w,
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h: h,
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dx: ((Math.random() - 0.5) * 0.05) * (0.5 + speedFactor * 2), // Velocity
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color: Math.random() > 0.5 ? "255,255,255" : "210,210,190",
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blur: Math.random() * 3 + 1
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});
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}
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}, 600);
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function renderClouds(ctx) {
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ctx.strokeStyle = "transparent";
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ctx.globalAlpha = Math.min(pixelTicks * 0.02,1);
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for (var i = 0;i < clouds.length;i++) {
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var cloud = clouds[i];
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var gradient = ctx.createLinearGradient(
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cloud.x * pixelSize, cloud.y * pixelSize,
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cloud.x * pixelSize, (cloud.y + cloud.h) * pixelSize
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);
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gradient.addColorStop(0, `RGBA(${cloud.color},0.1)`);
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gradient.addColorStop(1, `RGBA(${cloud.color},0.2)`);
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ctx.filter = `blur(${cloud.blur}px)`;
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ctx.fillStyle = gradient;
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ctx.fillRect(cloud.x * pixelSize, cloud.y * pixelSize, cloud.w * pixelSize, cloud.h * pixelSize);
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ctx.filter = "none";
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}
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}
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function updateClouds() {
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if (paused) {return;}
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for (var i = 0;i < clouds.length;i++) {
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var cloud = clouds[i];
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cloud.x += cloud.dx;
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// Wrap around
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if (cloud.x > width) {
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cloud.x = -cloud.w;
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} else if (cloud.x + cloud.w < 0) {
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cloud.x = width;
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}
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}
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}
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renderPrePixel(renderClouds);
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runEveryTick(updateClouds);
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