#!/usr/bin/env python import time import wx npts = 100000 def TestLinesFromBuffer(dc, log): global npts try: import numpy as np start = time.time() w, h = dc.GetSize() vs = np.linspace(0, 1, npts).reshape((npts, 1)) x1 = np.cos(vs * 12 * np.pi) * w/2 * vs + w/2 x2 = np.cos(vs * 16 * np.pi) * w/2 * vs + w/2 y1 = np.sin(vs * 12 * np.pi) * w/2 * vs + h/2 y2 = np.sin(vs * 16 * np.pi) * w/2 * vs + h/2 # Data has to be the same size as a C integer pts1 = np.append(x1, y1, 1).astype('intc') pts2 = np.append(x2, y2, 1).astype('intc') dc.SetPen(wx.BLACK_PEN) t1 = time.time() dc.DrawLines(pts1) t2 = time.time() dc.SetPen(wx.RED_PEN) t3 = time.time() dc.DrawLinesFromBuffer(pts2) t4 = time.time() log.write("%s pts: %s seconds with DrawLines %s seconds with DrawLinesFromBuffer\n" % (npts, t2 - t1, t4 - t3)) except ImportError: log.write("Couldn't import numpy") pass # Class used for all the various sample pages; the mechanics are the same # for each one with regards to the notebook. The only difference is # the function we use to draw on it. class DrawPanel(wx.Panel): def __init__(self, parent, drawFun, log): wx.Panel.__init__(self, parent, -1) self.SetBackgroundColour(wx.WHITE) self.log = log self.drawFun = drawFun self.Bind(wx.EVT_PAINT, self.OnPaint) def OnSize(self, evt): self.Refresh() def OnPaint(self, evt): dc = wx.PaintDC(self) dc.Clear() self.drawFun(dc,self.log) #---------------------------------------------------------------------- def runTest(frame, nb, log): global npts panel = wx.Panel(nb, -1) vsizer = wx.BoxSizer(wx.VERTICAL) hsizer = wx.BoxSizer(wx.HORIZONTAL) hsizer.Add(wx.StaticText(panel, -1, "# of Points"), 0, wx.ALIGN_CENTER|wx.ALL, 5) npts_ctrl = wx.TextCtrl(panel, -1, str(npts)) hsizer.Add(npts_ctrl, 0, wx.ALIGN_CENTER|wx.ALL, 5) button = wx.Button(panel, -1, "Refresh") hsizer.Add(button, 0, wx.ALIGN_CENTER|wx.ALL, 5) vsizer.Add(hsizer, 0, wx.ALIGN_CENTER, 0) win = DrawPanel(panel, TestLinesFromBuffer, log) vsizer.Add(win, 1, wx.GROW, 0) panel.SetSizer(vsizer) def update_npts(evt): global npts val = npts_ctrl.GetValue() try: npts = int(val) except ValueError: log.write("Error converting %s to an int" % (val)) win.Refresh() button.Bind(wx.EVT_BUTTON, update_npts) return panel #---------------------------------------------------------------------- overview = """\ The DrawLinesFromBuffer function has been added to wx.DC to provide a way to draw directly from a numpy array or other object that implements the python buffer protocol.
    DrawLinesFromBuffer(pyBuff)
The buffer object needs to provide an array of C integers organized as x, y point pairs. The size of a C integer is platform dependent. With numpy, the intc data type will provide the appropriate element size. If called with an object that doesn't support the python buffer protocol, or if the underlying element size does not match the size of a C integer, a TypeError exception is raised. If the buffer provided has float data with the same element size as a C integer, no error will be raised, but the lines will not be drawn in the appropriate places. """ if __name__ == '__main__': import sys,os import run run.main(['', os.path.basename(sys.argv[0])] + sys.argv[1:])