2b:null 2c:["$","title",null,{"children":"Galaxy Map Generation | Tim Garvin | Observable"}] 31:T4eb,{ //const dpi = window.devicePixelRatio || 1; const canvas = DOM.canvas(width, height); const context = canvas.getContext("2d"); context.beginPath(); context.arc(width / 2, height / 2, coreRadius, 0, 2 * Math.PI); context.fillStyle = '#999999'; context.fill(); yield canvas; context.fillStyle = '#000'; for (const star of stars) { context.beginPath(); context.arc(star.x, star.y, 4, 0, 2 * Math.PI); context.fill(); if (animation) { yield canvas; } } for (let i = 0; i < triangles.length; i += 3) { const i0 = triangles[i + 0], p0 = stars[i0]; const i1 = triangles[i + 1], p1 = stars[i1]; const i2 = triangles[i + 2], p2 = stars[i2]; context.beginPath(); if (i0 < i1 && distance(p0,p1) < maxLaneLength && Math.random()*100 > edgeThinning) context.moveTo(p0.x, p0.y), context.lineTo(p1.x, p1.y); if (i1 < i2 && distance(p1,p2) < maxLaneLength && Math.random()*100 > edgeThinning) context.moveTo(p1.x, p1.y), context.lineTo(p2.x, p2.y); if (i2 < i0 && distance(p2,p0) < maxLaneLength && Math.random()*100 > edgeThinning) context.moveTo(p2.x, p2.y), context.lineTo(p0.x, p0.y); context.stroke(); if (animation) { yield canvas; } } return canvas; }32:[] 2f:{"id":"28c1ddf8581aab41","slug":"galaxy-map-generation","title":"Galaxy Map Generation","thumbnail":"5f1f60ad51973366de02def0040952b06248638eac54aa00e9b27df90b73c6bd","access_level":"public","create_time":"$D2021-04-09T16:24:12.335Z","update_time":"$D2021-05-04T18:09:59.606Z","view_time":null,"first_public_time":"$D2021-04-10T04:52:36.696Z","fork":false,"stars":1,"starred":false,"owner":{"type":"team","id":"bd83fd4aa63f66d4","login":"tcgarvin","name":"Tim Garvin","avatar_url":"https://avatars-next.observableusercontent.com/0a401f190f78dde3ab907b150924a42cc24ef3250274037aab2c952c0495c664","tier":"starter_2024"},"version":265,"publish_version":265,"role":null,"authored":false,"authors":[{"type":"individual","id":"3a9edae390009386","login":"tcgarvin","name":"Tim Garvin","avatar_url":"https://avatars-next.observableusercontent.com/0a401f190f78dde3ab907b150924a42cc24ef3250274037aab2c952c0495c664","tier":null}],"members":[{"type":"individual","id":"3a9edae390009386","login":"tcgarvin","name":"Tim Garvin","avatar_url":"https://avatars-next.observableusercontent.com/0a401f190f78dde3ab907b150924a42cc24ef3250274037aab2c952c0495c664","tier":null,"role":"editor"}],"comments":[],"custom_thumbnail":true,"trashed":false,"lapsed":null,"subscribed":null,"forks":2,"collection":null,"type":"notebook","body":{"title":"Galaxy Map Generation","cells":[{"id":176,"value":"md`# Galaxy Map Generation`\n","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":67,"value":"$31","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":148,"value":"viewof numStars = Range([10, 500], {label: \"Stars\", step: 5, value: 200})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":153,"value":"viewof coreRadius = Range([0, 100], {label: \"Core Radius\", step: 5, value: 50})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":159,"value":"viewof starMargin = Range([0, 20], {label: \"Star Margin\", step: 1, value: 4})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":168,"value":"viewof maxLaneLength = Range([10, 300], {label: \"Max Lane Length\", step: 5, value: 75})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":209,"value":"viewof edgeThinning = Range([0,80], {label: \"%Edges to Remove\", step:1, value: 50})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":191,"value":"viewof animation = Toggle({label: \"Animation\", value: true})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":0,"value":"md`## Background \n\nA toy. Some of the display code is forked with thanks from Mike Bostock's [Blue Noise Delaunay\n](https://observablehq.com/@mbostock/blue-noise-delaunay) notebook.\n\nThis notebook is for exploring algorithms that generate a simple \"galaxy\" for use in an economic simulation. Aethetically, I'm looking for something not so unlike Escape Velocity.\n`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":235,"value":"md`## Features\n\n- Stars: Number of stars\n- Core Radius: The size of the center of the galaxy, in which no habitable stars occur, and in which naviation is limited\n- Star Margin: Minimum distance between stars. This margin is added to the radius of the star dots themselves\n- Max Lane Length: We start with all edges provided by Delaunay Triangles. We then remove edges longer than this maxiumum, resulting in a more pleasing set of edges\n- %Edges to Remove: After removing edges longer than the max, we additionally remove this percent of all edges randomly. This makes the structure of the edges less boring\n- Animation: Whether or not to animate the contruction of the galaxy. The animation is not great, but kind of satisfying to watch\n`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":251,"value":"md`## Data`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":116,"value":"stars = [...pointGenerator({x:width/2, y:height/2}, Math.min(height, width) / 6, starRadius * 2 + starMargin, numStars, Math.min(width/2, height/2))]","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":120,"value":"triangles = new delaunator(stars, p => p.x, p => p.y).triangles","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":195,"value":"md`## Helpers`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":48,"value":"function distance(a, b) {\n return Math.sqrt((a.x - b.x)**2 + (a.y - b.y)**2)\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":7,"value":"function generatePoint(origin, sigma, maxDistanceFromOrigin) {\n let point = {x:d3.randomNormal(origin.x, sigma)(), y:d3.randomNormal(origin.y, sigma)()}\n if (distance(point, origin) > maxDistanceFromOrigin) {\n point = generatePoint(origin, sigma, maxDistanceFromOrigin)\n }\n return point\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":25,"value":"function shouldRemoveFromCircle(point, origin, radius) {\n let pointRadius = distance(point, origin);\n return pointRadius < radius;\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":43,"value":"function* pointGenerator(origin, sigma, minDistance, amount, maxDistanceFromOrigin) {\n let points = [];\n nextPoint: while (points.length < amount) {\n \n let point = generatePoint(origin, sigma)\n if (shouldRemoveFromCircle(point, origin, coreRadius, maxDistanceFromOrigin)) {\n continue nextPoint;\n }\n for (let otherPoint of points) {\n if (distance(point, otherPoint) < minDistance) {\n continue nextPoint\n } \n }\n points.push(point)\n yield point\n }\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":69,"value":"md`## Constants`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":71,"value":"height = Math.min(600, width)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":156,"value":"starRadius = 4","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":39,"value":"md`## Dependencies`","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":142,"value":"import {Range, Toggle} from \"@observablehq/inputs\"","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":35,"value":"delaunator = require(\"delaunator@1\")","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":9,"value":"d3 = require(\"d3@6\")","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"}],"files":"$W32","stdlib":"1","titling":"auto"}} 30:"$2f:body"