Improve wxPython OnPaint

Question

I have the following wx.Window:

class SketchWindow(wx.Window):

  def __init__(self, parent):
    wx.Window.__init__(self, parent, -1)
    self.SetBackgroundColour('White')
    # Window event binding
    self.Bind(wx.EVT_PAINT, self.OnPaint)
    self.Bind(wx.EVT_IDLE, self.OnIdle)
    # run
    self.Run()

  def OnPaint(self, evt):
    self.DrawEntities(wx.PaintDC(self))

  def DrawEntities(self, dc):
    dc.SetPen(wx.Pen('Black', 1, wx.SOLID))
    dc.SetBrush(wx.Brush('Green', wx.SOLID))
    # draw all
    for e in self.entities:
      x, y = e.location
      dc.DrawCircle(x, y, 4)

  def OnIdle(self, event):
    self.Refresh(False)

  def Run(self):
    # update self.entities ...
    # call this method again later
    wx.CallLater(50, self.Run)

I need to draw on my window a number of circles [0, 2000] every N milliseconds (50 in my example), where at each step these circles may update their location.

The method I wrote works (the circles are anti-aliased too) but it's quite slow. Is there a way to improve my solution?

Answer 1

I think the basic idea for better performance is to draw to memory offscreen, then blit the result to the screen. You could use the BufferedCanvas to accomplish this (example given at bottom of link page).