antipath/core/graphics/graphicbar.js

const gm = require('gm')

module.exports = {
  create(maxLength, value) {
    const path = require('path').join(__dirname, '/bar/')

    const bar = gm(path + 'dummy.png')
      .geometry('+0x16')
      .tile(maxLength)
      .transparent('white')

    if (value > 0) { 
      bar.montage(path + 'bar-full-left.png') 
    } else {
      bar.montage(path + 'bar-empty-left.png') 
    }

    for (let i = 0; i < maxLength - 2; i++) {
      if (i <= value - 2) {
        bar.montage(path + 'bar-full-mid.png') 
      } else {
        bar.montage(path + 'bar-empty-mid.png') 
      }
    }

    if (maxLength <= value) {
      bar.montage(path + 'bar-full-right.png')  
    } else {
      bar.montage(path + 'bar-empty-right.png')  
    }

    return bar.stream('PNG')
  },
}