class_docstr: Provides a canvas to render to, using an FBO.
      
class_docstr_tok: ["Provides","a","canvas","to","render","to",",","using","an","FBO","."]
code: def __init__(self):
      self._fbo = None
      self._physical_size = 1, 1
      self._fbo_size = -1, -1
  
file_path: vispy/vispy/app/backends/_offscreen_util.py
imports: from ..None import Application, Canvas
  from ...None import gloo
label_desc: Use image node_id 1 to create a new FrameBufferHelper object  with example: obj = FrameBufferHelper()