How to modify it to scale based on the pinch location

[07ke]

How to modify it to scale based on the pinch location

import type { Canvas } from 'fabric'
import Hammer from 'hammerjs'

export default class FabricHammer {
  currentScale: number | null = null
  currentScaleX: number | null = null
  currentScaleY: number | null = null
  currentRotation: number | null = null
  adjustScale = 1
  adjustScaleX = 1
  adjustScaleY = 1
  adjustRotation = 0

  constructor(private readonly canvas: Canvas) {
    const hammer = new Hammer.Manager(canvas.upperCanvasEl)
    const rotate = new Hammer.Rotate()
    const pinch = new Hammer.Pinch()
    hammer.add([pinch, rotate])
    hammer.get('rotate').set({ enable: true })
    hammer.get('pinch').set({ enable: true })

    hammer.on('pinchstart rotatestart', (e) => {
      //   console.log('start')
      this.adjustRotation -= e.rotation

      const object = canvas.getActiveObject()
      if (object) {
        this.adjustScaleX = object.scaleX
        this.adjustScaleY = object.scaleY
      }
    })

    hammer.on('pinchmove rotatemove', (e) => {
      this.currentRotation = this.adjustRotation + e.rotation
      this.currentScale = this.adjustScale * e.scale

      const object = canvas.getActiveObject()
      if (object) {
        this.currentScaleX = this.adjustScaleX * e.scale
        this.currentScaleY = this.adjustScaleY * e.scale

        // Blocks object from being resized too small (and maintains aspect ratio)
        if (
          !(this.currentScaleX > object.minScaleLimit && this.currentScaleY > object.minScaleLimit)
        ) {
          this.currentScaleX = object.scaleX
          this.currentScaleY = object.scaleY
        }

        object.set({ lockMovementX: true, lockMovementY: true })

        object.set('scaleX', this.currentScaleX)
        object.set('scaleY', this.currentScaleY)
        object.rotate(this.currentRotation!)
        object.setCoords()
        canvas.renderAll()
      }
    })

    hammer.on('pinchend rotateend', () => {
      this.adjustScale = this.currentScale!
      this.adjustRotation = this.currentRotation!
      this.adjustScaleX = this.currentScaleX!
      this.adjustScaleY = this.currentScaleY!

      const object = canvas.getActiveObject()
      if (object) {
        // Timeout is to smooth out jitteryness, especially on iOS (iPad)
        setTimeout(function () {
          object.set({
            lockMovementX: false,
            lockMovementY: false
          })
        }, 300)
      }
      canvas.renderAll()
    })
  }
}