wxPython/demo/BitmapFromBuffer.py

   1
   2 import wx
   3 import array
   4
   5 #----------------------------------------------------------------------
   6
   7 class TestPanel(wx.Panel):
   8     def __init__(self, parent, log):
   9         self.log = log
  10         wx.Panel.__init__(self, parent, -1)
  11         self.Bind(wx.EVT_PAINT, self.OnPaint)
  12         self.width, self.height = 120,120
  13
  14         self.MakeBitmapRGB(self.width, self.height)
  15         self.MakeBitmapRGBA(self.width, self.height)
  16         self.MakeBitmapRGBpA(self.width, self.height)
  17
  18     def GetRGB(self, x, y, bpp):
  19         # calculate some colour values for this sample based on x,y position
  20         r = g = b = 0
  21         if y < self.height/3:                           r = 255
  22         if y >= self.height/3 and y <= 2*self.height/3: g = 255
  23         if y > 2*self.height/3:                         b = 255
  24
  25         if bpp == 4:
  26             a = int(x * 255.0 / self.width)
  27             return r, g, b, a
  28         else:
  29             return r, g, b
  30
  31
  32     def MakeBitmapRGB(self, width, height):
  33         # Make a bitmap using an array of RGB bytes
  34         bpp = 3  # bytes per pixel
  35         bytes = array.array('B', [0] * width*height*bpp)
  36
  37         for y in xrange(height):
  38             for x in xrange(width):
  39                 offset = y*width*bpp + x*bpp
  40                 r,g,b = self.GetRGB(x, y, bpp)
  41                 bytes[offset + 0] = r
  42                 bytes[offset + 1] = g
  43                 bytes[offset + 2] = b
  44
  45         self.rgbBmp = wx.BitmapFromBuffer(width, height, bytes)
  46
  47
  48
  49     def MakeBitmapRGBA(self, width, height):
  50         # Make a bitmap using an array of RGBA bytes
  51         bpp = 4  # bytes per pixel
  52         bytes = array.array('B', [0] * width*height*bpp)
  53
  54         for y in xrange(height):
  55             for x in xrange(width):
  56                 offset = y*width*bpp + x*bpp
  57                 r,g,b,a = self.GetRGB(x, y, bpp)
  58                 bytes[offset + 0] = r
  59                 bytes[offset + 1] = g
  60                 bytes[offset + 2] = b
  61                 bytes[offset + 3] = a
  62
  63         self.rgbaBmp = wx.BitmapFromBufferRGBA(width, height, bytes)
  64
  65
  66     def MakeBitmapRGBpA(self, width, height):
  67         # Make a bitmap using an array of RGB bytes plus a separate
  68         # buffer for the alpha channel
  69         bpp = 3  # bytes per pixel
  70         bytes = array.array('B', [0] * width*height*bpp)
  71
  72         for y in xrange(height):
  73             for x in xrange(width):
  74                 offset = y*width*bpp + x*bpp
  75                 r,g,b = self.GetRGB(x, y, bpp)
  76                 bytes[offset + 0] = r
  77                 bytes[offset + 1] = g
  78                 bytes[offset + 2] = b
  79
  80         # just use an alpha buffer with a constant alpha value for all
  81         # pixels for this example, it could just as easily have
  82         # varying alpha values like the other sample.
  83         alpha = array.array('B', [128]*width*height)
  84         self.rgbaBmp2 = wx.BitmapFromBuffer(width, height, bytes, alpha)
  85
  86
  87     def DrawBitmapAndMessage(self, dc, bmp, msg, x_, y_):
  88         x, y = x_, y_
  89
  90         # draw some text to help show the alpha
  91         dc.SetFont(self.GetFont())
  92         while y < y_ + self.height + 2*dc.GetCharHeight():
  93             dc.DrawText(msg, x,y)
  94             y += dc.GetCharHeight() + 5
  95
  96         # draw the bitmap over the text
  97         dc.DrawBitmap(bmp, x+15,y_+15, True)
  98
  99
 100     def OnPaint(self, evt):
 101         dc = wx.PaintDC(self)
 102         self.DrawBitmapAndMessage(dc, self.rgbBmp,  "No alpha channel in this image", 30,35)
 103         self.DrawBitmapAndMessage(dc, self.rgbaBmp, "This image has some alpha", 325,35)
 104         self.DrawBitmapAndMessage(dc, self.rgbaBmp2,"This one made with RGB+A", 180,220)
 105
 106
 107
 108
 109
 110 #----------------------------------------------------------------------
 111
 112 def runTest(frame, nb, log):
 113     win = TestPanel(nb, log)
 114     return win
 115
 116 #----------------------------------------------------------------------
 117
 118
 119
 120 overview = """<html><body>
 121 <h2><center>BitmapFromBuffer</center></h2>
 122
 123 Two new wx.Bitmap factory functions allow you to create a wx.Bitmap
 124 directly from a data buffer.  The the buffer can be any Python object
 125 that implements the buffer interface, or is convertable to a buffer,
 126 such as a string or an array.  The new functions are: <ul>
 127
 128 <li><b>wx.BitmapFromBuffer</b>(width, height, dataBuffer, alphaBuffer=None):
 129 Creates the bitmap from a buffer of RGB bytes, optionally with a separate
 130 buffer of alpha bytes.
 131
 132 <li><b>wx.BitmapFromBufferRGBA</b>(width, height, dataBuffer): Creates
 133 the bitmap from a buffer containing RGBA bytes.
 134
 135 </ul>
 136
 137
 138
 139 </body></html>
 140 """
 141
 142
 143
 144 if __name__ == '__main__':
 145     import sys,os
 146     import run
 147     run.main(['', os.path.basename(sys.argv[0])] + sys.argv[1:])
 148