docstr: This method is called immediately before each draw.
  
  The *view* argument indicates which view is about to be drawn.
docstr_tok: ["This","method","is","called","immediately","before","each","draw",".","The","*","view","*","argument","indicates","which","view","is","about","to","be","drawn","."]
code: def _prepare_draw(self, view=None):
      """This method is called immediately before each draw.
  
      The *view* argument indicates which view is about to be drawn.
      """
      pass
  
imports: import numpy
  import math
  from vispy import gloo, app, scene
  from vispy.visuals import Visual
  from vispy.visuals.shaders import Function, Variable
  from vispy.visuals.transforms import TransformSystem, BaseTransform
  from vispy.util.profiler import Profiler
label_desc: Use image node_id 6 for calling the SignalsVisual obj's underlying member method code with example usage: obj._prepare_draw(view) without return types