Convert RLE to regl.framebuffer data

regl-life-initialize.js

 let decode = (rle) => rle.replace(/[\n\s]/g, '')
   .replace(/(\d+)(\w)/g, (m, n, c) => new Array(parseInt(n) + 1).join(c))

 let decoder = (rle) => {
   let rld = [];
   rle.replace('!', '').split('$').forEach(s => rld.push(decode(s)))
   return rld
 }

 // reg, green, blue, alpha
 let rgbAlpha = (rld) => { // rld: run-length decoded
   return rld.map(s => s.split('').map(c => ({
       'b': 0,
       'o': 255
     } [c])).map(x => [x, x, x, x]))
     .map(a => [].concat.apply([], a))
 }

 let initialize = (rle, p = START_POSITION) => { // p: starting position
   let rld = decoder(rle)
   let rgba = rgbAlpha(rld)
   let initialConditions = (Array(RADIUS * RADIUS * 4)).fill(0)
   for (let i = 0; i < rgba.length; i++) {
     for (let j = 0; j < rgba[i].length; j++) {
       initialConditions[p - i * 4 * RADIUS + j] = rgba[i][j]
     }
   }
   return initialConditions
 }

 const INITIAL_CONDITIONS = initialize(SIR_ROBIN)