code: def on_resize(self, event):
      self._set_projection(event.physical_size)
  
file_path: vispy/examples/gloo/post_processing.py
imports: import numpy
  from vispy import app
  from vispy.geometry import create_cube
  from vispy.util.transforms import perspective, translate, rotate
  from vispy.gloo import Program, VertexBuffer, IndexBuffer, Texture2D, clear, FrameBuffer, RenderBuffer, set_viewport, set_state
label_desc: Use image node_id 3 for calling the Canvas obj's underlying member method code with example usage: obj.on_resize(event) without return types