wxPython/wx/lib/imageutils.py

   1 #----------------------------------------------------------------------
   2 # Name:        wxPython.lib.imageutils
   3 # Purpose:     A collection of functions for simple image manipulations
   4 #
   5 # Author:      Robb Shecter
   6 #
   7 # Created:     7-Nov-2002
   8 # RCS-ID:      $Id$
   9 # Copyright:   (c) 2002 by
  10 # Licence:     wxWindows license
  11 #----------------------------------------------------------------------
  12
  13 import wx
  14
  15 def grayOut(anImage):
  16     """
  17     Convert the given image (in place) to a grayed-out
  18     version, appropriate for a 'disabled' appearance.
  19     """
  20     factor = 0.7        # 0 < f < 1.  Higher is grayer.
  21     if anImage.HasMask():
  22         maskColor = (anImage.GetMaskRed(), anImage.GetMaskGreen(), anImage.GetMaskBlue())
  23     else:
  24         maskColor = None
  25     data = map(ord, list(anImage.GetData()))
  26
  27     for i in range(0, len(data), 3):
  28         pixel = (data[i], data[i+1], data[i+2])
  29         pixel = makeGray(pixel, factor, maskColor)
  30         for x in range(3):
  31             data[i+x] = pixel[x]
  32     anImage.SetData(''.join(map(chr, data)))
  33
  34
  35 def makeGray((r,g,b), factor, maskColor):
  36     """
  37     Make a pixel grayed-out. If the pixel
  38     matches the maskColor, it won't be
  39     changed.
  40     """
  41     if (r,g,b) != maskColor:
  42         return map(lambda x: int((230 - x) * factor) + x, (r,g,b))
  43     else:
  44         return (r,g,b)
  45
  46
  47
  48 def stepColour(c, step):
  49     """
  50     stepColour is a utility function that simply darkens or lightens a
  51     color, based on the specified step value.  A step of 0 is
  52     completely black and a step of 200 is totally white, and 100
  53     results in the same color as was passed in.
  54     """
  55     def _blendColour(fg, bg, dstep):
  56         result = bg + (dstep * (fg - bg))
  57         if result < 0:
  58             result = 0
  59         if result > 255:
  60             result = 255
  61         return result
  62
  63     if step == 100:
  64         return c
  65
  66     r = c.Red()
  67     g = c.Green()
  68     b = c.Blue()
  69
  70     # step is 0..200 where 0 is completely black
  71     # and 200 is completely white and 100 is the same
  72     # convert that to a range of -1.0 .. 1.0
  73     step = min(step, 200)
  74     step = max(step, 0)
  75     dstep = (step - 100.0)/100.0
  76
  77     if step > 100:
  78         # blend with white
  79         bg = 255.0
  80         dstep = 1.0 - dstep  # 0 = transparent fg; 1 = opaque fg
  81     else:
  82         # blend with black
  83         bg = 0.0
  84         dstep = 1.0 + dstep;  # 0 = transparent fg; 1 = opaque fg
  85
  86     r = _blendColour(r, bg, dstep)
  87     g = _blendColour(g, bg, dstep)
  88     b = _blendColour(b, bg, dstep)
  89
  90     return wx.Colour(int(r), int(g), int(b))
  91