HarmonyOS canvas.drawCircle方法画出的圆形位置偏移

需要统一以下单位，demo如下：

@Entry
@Component
struct Index {
  private context: DrawingRenderingContext = new DrawingRenderingContext()

  build() {
    Stack() {
      Polyline({ width: '260px', height: '260px'})
        .points([['187.2px', '177.6px'], ['76.5px', '177.6px'], ['198px', '152.1px'], ['66.6px', '160.5px']])
        .fillOpacity(0)
        .stroke(Color.Black)
        .strokeWidth(3)

      Canvas(this.context)
        .width('260px')
        .height('260px')
        .onReady(() => {
          this.context.canvas.drawCircle(187.2, 177.6, 20)
          this.context.canvas.drawCircle(76.5, 177.6, 20)
          this.context.canvas.drawCircle(198, 152.1, 20)
          this.context.canvas.drawCircle(66.6, 160.5, 20)
          this.context.invalidate()
        })
    }
  }
}