-
import wx
+# use the numpy code instead of the raw access code for comparison
+USE_NUMPY = False
+
+# time the execution of making a bitmap?
+TIMEIT = False
+
+# how big to make the bitmaps
+DIM = 100
+
+#----------------------------------------------------------------------
+# attempt to import a numeric module if requested to
+
+if USE_NUMPY:
+ try:
+ import numpy
+ def makeByteArray(shape):
+ return numpy.empty(shape, numpy.uint8)
+ numtype = 'numpy'
+ except ImportError:
+ try:
+ import numarray
+ def makeByteArray(shape):
+ arr = numarray.array(shape=shape, typecode='u1')
+ arr[:] = 0
+ return arr
+ numtype = 'numarray'
+ except ImportError:
+ USE_NUMPY = False
+
+
#----------------------------------------------------------------------
class TestPanel(wx.Panel):
self.log = log
wx.Panel.__init__(self, parent, -1)
self.Bind(wx.EVT_PAINT, self.OnPaint)
-
- self.redBmp = self.MakeBitmap(178, 34, 34)
- self.greenBmp = self.MakeBitmap( 35, 142, 35)
- self.blueBmp = self.MakeBitmap( 0, 0, 139)
+
+ if TIMEIT:
+ import timeit
+ timeit.s = self # Put self in timeit's global namespace as
+ # 's' so it can be found in the code
+ # snippets being tested.
+ if not USE_NUMPY:
+ t = timeit.Timer("bmp = s.MakeBitmap(10, 20, 30)")
+ else:
+ t = timeit.Timer("bmp = s.MakeBitmap2(10, 20, 30)")
+ log.write("Timing...\n")
+ num = 100
+ tm = t.timeit(num)
+ log.write("%d passes in %f seconds == %f seconds per pass " %
+ (num, tm, tm/num))
+
+ if not USE_NUMPY:
+ log.write("using raw access\n")
+ self.redBmp = self.MakeBitmap(178, 34, 34)
+ self.greenBmp = self.MakeBitmap( 35, 142, 35)
+ self.blueBmp = self.MakeBitmap( 0, 0, 139)
+ else:
+ log.write("using %s\n" % numtype)
+ self.redBmp = self.MakeBitmap2(178, 34, 34)
+ self.greenBmp = self.MakeBitmap2( 35, 142, 35)
+ self.blueBmp = self.MakeBitmap2( 0, 0, 139)
+
+
+ def OnPaint(self, evt):
+ dc = wx.PaintDC(self)
+ dc.DrawBitmap(self.redBmp, 50, 50, True)
+ dc.DrawBitmap(self.greenBmp, 110, 110, True)
+ dc.DrawBitmap(self.blueBmp, 170, 50, True)
+
def MakeBitmap(self, red, green, blue, alpha=128):
- bmp = wx.EmptyBitmap(100, 100, 32)
+ # Create the bitmap that we will stuff pixel values into using
+ # the raw bitmap access classes.
+ bmp = wx.EmptyBitmap(DIM, DIM, 32)
# Create an object that facilitates access to the bitmap's
# pixel buffer
for pixel in pixelData:
pixel.Set(red, green, blue, alpha)
- # Next we'll use the pixel accessor to draw a border
+ # This block of code is another way to do the same as above,
+ # but with the accessor interface instead of the Python
+ # iterator. It is a bit faster than the above because it
+ # avoids the iterator/generator magic, but it is not nearly as
+ # 'clean' looking ;-)
+ #pixels = pixelData.GetPixels()
+ #for y in xrange(DIM):
+ # for x in xrange(DIM):
+ # pixels.Set(red, green, blue, alpha)
+ # pixels.nextPixel()
+ # pixels.MoveTo(pixelData, 0, y)
+
+
+ # Next we'll use the pixel accessor to set the border pixels
+ # to be fully opaque
pixels = pixelData.GetPixels()
- for x in xrange(100):
+ for x in xrange(DIM):
pixels.MoveTo(pixelData, x, 0)
pixels.Set(red, green, blue, wx.ALPHA_OPAQUE)
- pixels.MoveTo(pixelData, x, 99)
+ pixels.MoveTo(pixelData, x, DIM-1)
pixels.Set(red, green, blue, wx.ALPHA_OPAQUE)
- for y in xrange(100):
+ for y in xrange(DIM):
pixels.MoveTo(pixelData, 0, y)
pixels.Set(red, green, blue, wx.ALPHA_OPAQUE)
- pixels.MoveTo(pixelData, 99, y)
+ pixels.MoveTo(pixelData, DIM-1, y)
pixels.Set(red, green, blue, wx.ALPHA_OPAQUE)
return bmp
- def OnPaint(self, evt):
- dc = wx.PaintDC(self)
- dc.DrawBitmap(self.redBmp, 50, 50, True)
- dc.DrawBitmap(self.greenBmp, 110, 110, True)
- dc.DrawBitmap(self.blueBmp, 170, 50, True)
+ def MakeBitmap2(self, red, green, blue, alpha=128):
+ # Make an array of bytes that is DIM*DIM in size, with enough
+ # slots for each pixel to have a RGB and A value
+ arr = makeByteArray( (DIM,DIM, 4) )
+
+ # just some indexes to keep track of which byte is which
+ R, G, B, A = range(4)
+
+ # initialize all pixel values to the values passed in
+ arr[:,:,R] = red
+ arr[:,:,G] = green
+ arr[:,:,B] = blue
+ arr[:,:,A] = alpha
+
+ # Set the alpha for the border pixels to be fully opaque
+ arr[0, 0:DIM, A] = wx.ALPHA_OPAQUE # first row
+ arr[DIM-1, 0:DIM, A] = wx.ALPHA_OPAQUE # last row
+ arr[0:DIM, 0, A] = wx.ALPHA_OPAQUE # first col
+ arr[0:DIM, DIM-1, A] = wx.ALPHA_OPAQUE # last col
+
+ # finally, use the array to create a bitmap
+ bmp = wx.BitmapFromBufferRGBA(DIM, DIM, arr)
+ return bmp
+
+
#----------------------------------------------------------------------
to access the platform-specific pixel buffer within a wx.Bitmap. They
provide both a random access method, and an iterator interface.
+<p>Unfortunately, although these classes are convienient ways to access
+and update the contents of a wx.Bitmap, we lose most of the efficiency
+of the C++ classes by requiring one or more Python-to-C++ transitions
+for each pixel. In fact it can be <b>much</b> slower than the other
+ways of creating a bitmap from scratch, especially now that
+wx.BitmapFromBuffer exists and can save the time needed to copy from a
+wx.Image.
+
+<p>To see this difference for yourself this module has been
+instrumented to allow you to experiment with using either the raw
+access or numpy/numarray, and also to time how long it takes to create
+100 bitmaps like you see on the screen. Simply edit this module in
+the \"Demo Code\" tab and set TIMEIT to True and then watch
+the log window when the sample is reloaded. To try numpy or numarray
+(if you have them installed) then set USE_NUMPY to True as well, and
+watch the log window again. On my machines there is about <b>an
+order of magnitude</b> difference between the raw access functions
+and using a numarray.array with wx.BitmapFromBufferRGBA! Almost
+another order of magnitude improvement can be gained with using the
+new numpy module!
+
</body></html>
"""
projects / wxWidgets.git / commitdiff
