Created
November 18, 2017 08:33
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Random dots and non-random dots
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| <!DOCTYPE html> | |
| <html> | |
| <head> | |
| <title>Random Plot</title> | |
| <style> | |
| canvas { border: solid 1px; } | |
| th { font-family: monospace; } | |
| </style> | |
| </head> | |
| <body> | |
| <table> | |
| <tr> | |
| <td><canvas id="canvas1" width="400" height="300"></canvas></td> | |
| <td><canvas id="canvas2" width="400" height="300"></canvas></td> | |
| </tr> | |
| </table> | |
| <script> | |
| 'use strict'; | |
| const drawRandomDots = (canvasId, num, acceptable = (x, y) => true) => { | |
| const canvas = document.getElementById(canvasId); | |
| const ctx = canvas.getContext("2d"); | |
| ctx.fillStyle = "green"; | |
| while (num--) { | |
| while (true) { | |
| const x = Math.floor(Math.random() * canvas.width); | |
| const y = Math.floor(Math.random() * canvas.height); | |
| if (acceptable(x, y)) { | |
| ctx.beginPath(); | |
| ctx.arc(x, y, 3, 0, Math.PI*2, false); | |
| ctx.fill(); | |
| break; | |
| } | |
| } | |
| } | |
| }; | |
| const apartAtLeast = (distance) => { | |
| const memo = []; | |
| return (x, y) => { | |
| if (memo.every((e) => Math.hypot(x - e[0], y - e[1]) > distance)) { | |
| memo.push([x, y]); | |
| return true; | |
| } else { | |
| return false; | |
| } | |
| }; | |
| }; | |
| drawRandomDots("canvas1", 500); | |
| drawRandomDots("canvas2", 500, apartAtLeast(10)); | |
| </script> | |
| </body> | |
| </html> |
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