X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/ecc0e221ee47e8be9fe367bd68ec0e53bea1142e..0a5bb138a71dfc1c706fc0858fb2801500e2c2e8:/wxPython/demo/RawBitmapAccess.py?ds=sidebyside diff --git a/wxPython/demo/RawBitmapAccess.py b/wxPython/demo/RawBitmapAccess.py index 2e0e57d384..4fddf31a0f 100644 --- a/wxPython/demo/RawBitmapAccess.py +++ b/wxPython/demo/RawBitmapAccess.py @@ -1,6 +1,35 @@ - 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): @@ -8,13 +37,45 @@ class TestPanel(wx.Panel): self.log = log wx.Panel.__init__(self, parent, -1) self.Bind(wx.EVT_PAINT, self.OnPaint) - - self.redBmp = self.MakeBitmap(188, 143, 234) - self.greenBmp = self.MakeBitmap(35, 142, 35) - self.blueBmp = self.MakeBitmap(50, 153, 204) + + 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 @@ -28,27 +89,61 @@ class TestPanel(wx.Panel): 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 + + #---------------------------------------------------------------------- @@ -67,6 +162,27 @@ wx.NativePixelData and wx.AlphaPixelData provide a cross-platform way to access the platform-specific pixel buffer within a wx.Bitmap. They provide both a random access method, and an iterator interface. +

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 much 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. + +

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 an +order of magnitude 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! + """