💡 Performance: only calculate points once
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41c3ce8b17
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72
bundle.js
72
bundle.js
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@ -491,18 +491,18 @@ function _typeof(obj) { return obj && typeof Symbol !== "undefined" && obj.const
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};
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/**
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* Apply the chaos game: starting from `start`, we plot
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* the next `n` points. To get to the next point, we apply
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* a random transformation among given ones
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* Starting from the last point in `points`, add
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* `iterations` number of point generated by applying
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* transformations chosen at random among `transforms`
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*
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* @param {Array} start Starting point
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* @param {Array} points Initial set of points
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* @param {number} iterations Number of points to plot
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* @param {Array} transforms List of available transforms
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* @param {Array} weights Probability weights for each transform
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* @return {null}
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*/
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var applyChaos = exports.applyChaos = function applyChaos(start, iterations, transforms, weights, cb) {
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var point = start;
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var applyChaos = exports.applyChaos = function applyChaos(points, iterations, transforms, weights) {
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var point = points[points.length - 1];
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if (weights === undefined) {
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weights = Array.apply(null, Array(transforms.length)).map(function () {
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@ -513,8 +513,7 @@ function _typeof(obj) { return obj && typeof Symbol !== "undefined" && obj.const
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while (iterations--) {
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var index = chooseIndex(weights);
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point = transforms[index](point);
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cb(point);
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points.push(point);
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}
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};
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}, {}], 7: [function (require, module, exports) {
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@ -571,6 +570,8 @@ function _typeof(obj) { return obj && typeof Symbol !== "undefined" && obj.const
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var width = undefined,
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height = undefined;
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var points = [[0, 0]];
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/**
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* Re-render the scene from scratch
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*
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@ -587,24 +588,22 @@ function _typeof(obj) { return obj && typeof Symbol !== "undefined" && obj.const
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// do the chaos game
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var image = ctx.getImageData(0, 0, width, height);
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var length = points.length;
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var color = [0, 0, 0];
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var skip = 50;
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_chaos.applyChaos.apply(undefined, [[0, 0], 200000].concat(_toConsumableArray(_ifs.barnsley), [function (point) {
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var x = Math.floor(point[0] * zoom + center[0]);
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var y = height - Math.floor(point[1] * zoom + center[1]);
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for (var i = 50; i < length; i += 1) {
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var x = Math.floor(points[i][0] * zoom + center[0]);
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var y = height - Math.floor(points[i][1] * zoom + center[1]);
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if (x >= 0 && x < width && y >= 0 && y < height && skip <= 0) {
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var i = (y * width + x) * 4;
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if (x >= 0 && x < width && y >= 0 && y < height) {
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var index = (y * width + x) * 4;
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image.data[i] = color[0];
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image.data[i + 1] = color[1];
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image.data[i + 2] = color[2];
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image.data[i + 3] = 255;
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image.data[index] = color[0];
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image.data[index + 1] = color[1];
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image.data[index + 2] = color[2];
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image.data[index + 3] = 255;
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}
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skip -= 1;
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}]));
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}
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ctx.putImageData(image, 0, 0);
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};
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@ -627,7 +626,7 @@ function _typeof(obj) { return obj && typeof Symbol !== "undefined" && obj.const
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*/
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content.on('wheel', function (event) {
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var delta = event.deltaMode === 0 ? event.deltaY / 53 : event.deltaY;
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var newZoom = zoom * (1 - delta * .035);
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var newZoom = zoom * Math.max(0, 1 - delta * .035);
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// which (unprojected) point does the mouse point on?
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var mouse = [(event.offsetX - center[0]) / zoom, (height - event.offsetY - center[1]) / zoom];
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@ -638,9 +637,33 @@ function _typeof(obj) { return obj && typeof Symbol !== "undefined" && obj.const
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// => newCenter = mouse * zoom - mouse * newZoom + center
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center = [mouse[0] * zoom - mouse[0] * newZoom + center[0], mouse[1] * zoom - mouse[1] * newZoom + center[1]];
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zoom = newZoom;
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render();
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if (newZoom > zoom) {
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_chaos.applyChaos.apply(undefined, [points, Math.floor((newZoom - zoom) * 1000)].concat(_toConsumableArray(_ifs.sierpinski)));
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} else {
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// points = points.slice(0, points.length + Math.floor((newZoom - zoom) * 1000));
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}
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zoom = newZoom;
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// time for some GC
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if (points.length > 1000000) {
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var length = points.length;
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var newPoints = [];
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var i = 0;
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for (i = 0; i < length; i += 1) {
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var x = Math.floor(points[i][0] * zoom + center[0]);
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var y = height - Math.floor(points[i][1] * zoom + center[1]);
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if (x >= 0 && x < width && y >= 0 && y < height) {
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newPoints.push(points[i]);
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}
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}
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points = newPoints;
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}
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render();
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event.preventDefault();
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});
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@ -668,6 +691,7 @@ function _typeof(obj) { return obj && typeof Symbol !== "undefined" && obj.const
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}
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});
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_chaos.applyChaos.apply(undefined, [points, 200000].concat(_toConsumableArray(_ifs.sierpinski)));
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window.onresize = resize;
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resize();
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}, { "./chaos": 6, "./ifs": 7, "the-dom": 1 }] }, {}, [8]);
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@ -20,18 +20,18 @@ const chooseIndex = weights => {
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};
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/**
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* Apply the chaos game: starting from `start`, we plot
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* the next `n` points. To get to the next point, we apply
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* a random transformation among given ones
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* Starting from the last point in `points`, add
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* `iterations` number of point generated by applying
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* transformations chosen at random among `transforms`
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*
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* @param {Array} start Starting point
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* @param {Array} points Initial set of points
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* @param {number} iterations Number of points to plot
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* @param {Array} transforms List of available transforms
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* @param {Array} weights Probability weights for each transform
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* @return {null}
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*/
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export const applyChaos = (start, iterations, transforms, weights, cb) => {
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let point = start;
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export const applyChaos = (points, iterations, transforms, weights) => {
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let point = points[points.length - 1];
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if (weights === undefined) {
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weights = Array.apply(null, Array(transforms.length)).map(
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@ -42,7 +42,6 @@ export const applyChaos = (start, iterations, transforms, weights, cb) => {
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while (iterations--) {
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const index = chooseIndex(weights);
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point = transforms[index](point);
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cb(point);
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points.push(point);
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}
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};
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@ -14,6 +14,8 @@ let dragging = false;
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let center, zoom = 200;
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let width, height;
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let points = [[0, 0]];
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/**
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* Re-render the scene from scratch
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*
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@ -30,24 +32,22 @@ const render = () => {
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// do the chaos game
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const image = ctx.getImageData(0, 0, width, height);
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const length = points.length;
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const color = [0, 0, 0];
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let skip = 50;
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applyChaos([0, 0], 200000, ...barnsley, point => {
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const x = Math.floor(point[0] * zoom + center[0]);
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const y = height - Math.floor(point[1] * zoom + center[1]);
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for (let i = 50; i < length; i += 1) {
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const x = Math.floor(points[i][0] * zoom + center[0]);
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const y = height - Math.floor(points[i][1] * zoom + center[1]);
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if (x >= 0 && x < width && y >= 0 && y < height && skip <= 0) {
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const i = (y * width + x) * 4;
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if (x >= 0 && x < width && y >= 0 && y < height) {
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const index = (y * width + x) * 4;
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image.data[i] = color[0];
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image.data[i + 1] = color[1];
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image.data[i + 2] = color[2];
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image.data[i + 3] = 255;
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image.data[index] = color[0];
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image.data[index + 1] = color[1];
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image.data[index + 2] = color[2];
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image.data[index + 3] = 255;
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}
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skip -= 1;
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});
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}
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ctx.putImageData(image, 0, 0);
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};
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@ -70,7 +70,7 @@ const resize = () => {
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*/
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content.on('wheel', event => {
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const delta = event.deltaMode === 0 ? event.deltaY / 53 : event.deltaY;
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const newZoom = zoom * (1 - delta * .035);
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const newZoom = zoom * Math.max(0, 1 - delta * .035);
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// which (unprojected) point does the mouse point on?
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const mouse = [
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@ -113,5 +113,6 @@ content.on('mousemove', event => {
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}
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});
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applyChaos(points, 200000, ...barnsley);
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window.onresize = resize;
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resize();
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