code: def on_draw(self, event):
      # Clear
      gloo.clear()
  
      # Draw
      self._program["sizeFactor"] = 0.5 + np.sin(time.time() * 3) * 0.2
  
      # Draw (pick one!)
      # self._program.draw('triangle_strip')
      self._program.draw("triangles", indices_buffer)
  
file_path: vispy/examples/gloo/animate_shape.py
imports: import time
  import numpy
  from vispy import gloo
  from vispy import app
label_desc: Use image node_id 3 for calling the Canvas obj's underlying member method code with example usage: obj.on_draw(event) without return types