code: func (c *Canvas) MakePicture(p pixel.Picture) pixel.TargetPicture {
  	if cp, ok := p.(*canvasPicture); ok {
  		return &canvasPicture{
  			GLPicture: cp.GLPicture,
  			dst:       c,
  		}
  	}
  	if gp, ok := p.(GLPicture); ok {
  		return &canvasPicture{
  			GLPicture: gp,
  			dst:       c,
  		}
  	}
  	return &canvasPicture{
  		GLPicture: NewGLPicture(p),
  		dst:       c,
  	}
  }
docs: // MakePicture create a specialized copy of the supplied Picture that draws onto this Canvas.
  //
  // PictureColor is supported.