30:T537,{ const edges = [...generate(cellWidth, cellHeight)]; const width = cellWidth * (cellSize + cellSpacing) + cellSpacing; const height = cellHeight * (cellSize + cellSpacing) + cellSpacing; const context = DOM.context2d(width, height); context.canvas.style.background = "#000"; context.canvas.style.imageRendering = "pixelated"; context.fillStyle = "#fff"; yield context.canvas; for (let m = 240, k = 4, i = -m, n = edges.length; i < n; i += k) { for (let j = Math.max(0, i - k), i1 = Math.min(n, i + m); j < i1; ++j) { const {index, direction} = edges[j]; context.fillStyle = `hsl(0,100%,${(1 - Math.max(0, j - i) / m) * 100}%)`; switch (direction) { case E: { fillCell(context, index + 1); fillEast(context, index); break; } case W: { fillCell(context, index - 1); fillEast(context, index - 1); break; } case S: { fillCell(context, index + cellWidth); fillSouth(context, index); break; } case N: { fillCell(context, index - cellWidth); fillSouth(context, index - cellWidth); break; } default: { fillCell(context, index); break; } } } yield context.canvas; } }31:T535,function* generate(cellWidth, cellHeight) { const heap = new Queue(); const cells = new Uint8Array(cellWidth * cellHeight); const index = (cellWidth >> 1) + (cellHeight >> 1) * cellWidth; let edge; heap.push({index, direction: N}, Math.random()); heap.push({index, direction: E}, Math.random()); yield {index}; while (edge = heap.pop()) { let i0 = edge.index, i1; let d0 = edge.direction, d1; let x0 = i0 % cellWidth, x1; let y0 = i0 / cellWidth | 0, y1; if (d0 === N) i1 = i0 - cellWidth, x1 = x0, y1 = y0 - 1, d1 = S; else if (d0 === S) i1 = i0 + cellWidth, x1 = x0, y1 = y0 + 1, d1 = N; else if (d0 === W) i1 = i0 - 1, x1 = x0 - 1, y1 = y0, d1 = E; else i1 = i0 + 1, x1 = x0 + 1, y1 = y0, d1 = W; if (cells[i1] === 0) { cells[i0] |= d0, cells[i1] |= d1; yield edge; if (y1 > 0 && cells[i1 - cellWidth] === 0) { heap.push({index: i1, direction: N}, Math.random()); } if (y1 < cellHeight - 1 && cells[i1 + cellWidth] === 0) { heap.push({index: i1, direction: S}, Math.random()); } if (x1 > 0 && cells[i1 - 1] === 0) { heap.push({index: i1, direction: W}, Math.random()); } if (x1 < cellWidth - 1 && cells[i1 + 1] === 0) { heap.push({index: i1, direction: E}, Math.random()); } } } }32:[] 2e:{"title":"Prim’s Algorithm","cells":[{"id":0,"value":"md`# Prim’s Algorithm\n\nThis maze is generated using Prim’s algorithm.`","pinned":false,"hidden":false,"mode":"ojs"},{"id":3,"value":"$30","pinned":true,"hidden":false,"mode":"ojs"},{"id":8,"value":"$31","pinned":true,"hidden":false,"mode":"ojs"},{"id":171,"value":"function fillCell(context, i) {\n const x = i % cellWidth;\n const y = i / cellWidth | 0;\n context.fillRect(\n x * cellSize + (x + 1) * cellSpacing,\n y * cellSize + (y + 1) * cellSpacing,\n cellSize, cellSize\n );\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":168,"value":"function fillEast(context, i) {\n const x = i % cellWidth;\n const y = i / cellWidth | 0;\n context.fillRect(\n (x + 1) * (cellSize + cellSpacing),\n y * cellSize + (y + 1) * cellSpacing,\n cellSpacing, cellSize\n );\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":174,"value":"function fillSouth(context, i) {\n const x = i % cellWidth;\n const y = i / cellWidth | 0;\n context.fillRect(\n x * cellSize + (x + 1) * cellSpacing,\n (y + 1) * (cellSize + cellSpacing),\n cellSize, cellSpacing\n );\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":28,"value":"cellSize = 3","pinned":true,"hidden":false,"mode":"ojs"},{"id":30,"value":"cellSpacing = 1","pinned":true,"hidden":false,"mode":"ojs"},{"id":32,"value":"cellWidth = Math.floor((width - cellSpacing) / (cellSize + cellSpacing))","pinned":true,"hidden":false,"mode":"ojs"},{"id":34,"value":"cellHeight = Math.floor((600 - cellSpacing) / (cellSize + cellSpacing))","pinned":true,"hidden":false,"mode":"ojs"},{"id":19,"value":"N = 1 << 0","pinned":true,"hidden":false,"mode":"ojs"},{"id":21,"value":"S = 1 << 1","pinned":true,"hidden":false,"mode":"ojs"},{"id":23,"value":"W = 1 << 2","pinned":true,"hidden":false,"mode":"ojs"},{"id":25,"value":"E = 1 << 3","pinned":true,"hidden":false,"mode":"ojs"},{"id":6,"value":"Queue = require(\"flatqueue@1\")","pinned":true,"hidden":false,"mode":"ojs"}],"files":"$W32","stdlib":"1","titling":"auto"}