@napi-rs/canvas/index.js

Canvas for Node.js with skia backend

const { platform, homedir } = require('os')
const { join } = require('path')

const {
  clearAllCache,
  CanvasRenderingContext2D,
  CanvasElement,
  SVGCanvas,
  Path: Path2D,
  ImageData,
  Image,
  FontKey,
  GlobalFonts,
  PathOp,
  FillType,
  StrokeJoin,
  StrokeCap,
  convertSVGTextToPath,
} = require('./js-binding')

const { DOMPoint, DOMMatrix, DOMRect } = require('./geometry')

const loadImage = require('./load-image')

const SvgExportFlag = {
  ConvertTextToPaths: 0x01,
  NoPrettyXML: 0x02,
  RelativePathEncoding: 0x04,
}

if (!('families' in GlobalFonts)) {
  Object.defineProperty(GlobalFonts, 'families', {
    get: function () {
      return JSON.parse(GlobalFonts.getFamilies().toString())
    },
  })
}

if (!('has' in GlobalFonts)) {
  Object.defineProperty(GlobalFonts, 'has', {
    value: function has(name) {
      return !!JSON.parse(GlobalFonts.getFamilies().toString()).find(({ family }) => family === name)
    },
    configurable: false,
    enumerable: false,
    writable: false,
  })
}

const _getTransform = CanvasRenderingContext2D.prototype.getTransform

CanvasRenderingContext2D.prototype.getTransform = function getTransform() {
  const transform = _getTransform.apply(this, arguments)
  // monkey patched, skip
  if (transform instanceof DOMMatrix) {
    return transform
  }
  const { a, b, c, d, e, f } = transform
  return new DOMMatrix([a, b, c, d, e, f])
}

function createCanvas(width, height, flag) {
  const isSvgBackend = typeof flag !== 'undefined'
  return isSvgBackend ? new SVGCanvas(width, height, flag) : new CanvasElement(width, height)
}

class Canvas {
  constructor(width, height, flag) {
    return createCanvas(width, height, flag)
  }

  static [Symbol.hasInstance](instance) {
    return instance instanceof CanvasElement || instance instanceof SVGCanvas
  }
}

if (!process.env.DISABLE_SYSTEM_FONTS_LOAD) {
  GlobalFonts.loadSystemFonts()
  const platformName = platform()
  const homedirPath = homedir()
  switch (platformName) {
    case 'win32':
      GlobalFonts.loadFontsFromDir(join(homedirPath, 'AppData', 'Local', 'Microsoft', 'Windows', 'Fonts'))
      break
    case 'darwin':
      GlobalFonts.loadFontsFromDir(join(homedirPath, 'Library', 'Fonts'))
      break
    case 'linux':
      GlobalFonts.loadFontsFromDir(join('usr', 'local', 'share', 'fonts'))
      GlobalFonts.loadFontsFromDir(join(homedirPath, '.fonts'))
      break
  }
}

module.exports = {
  clearAllCache,
  Canvas,
  createCanvas,
  Path2D,
  ImageData,
  Image,
  PathOp,
  FillType,
  StrokeCap,
  StrokeJoin,
  SvgExportFlag,
  GlobalFonts: GlobalFonts,
  convertSVGTextToPath,
  DOMPoint,
  DOMMatrix,
  DOMRect,
  loadImage,
  FontKey,
}