share/extensions/color_custom.py

   1 #!/usr/bin/env python
   2 import coloreffect
   3
   4 class C(coloreffect.ColorEffect):
   5     def __init__(self):
   6         coloreffect.ColorEffect.__init__(self)
   7         self.OptionParser.add_option("--r",
   8             action="store", type="string",
   9             dest="rFunction", default="r",
  10             help="red channel function")
  11         self.OptionParser.add_option("--g",
  12             action="store", type="string",
  13             dest="gFunction", default="g",
  14             help="green channel function")
  15         self.OptionParser.add_option("--b",
  16             action="store", type="string",
  17             dest="bFunction", default="b",
  18             help="blue channel function")
  19         self.OptionParser.add_option("--tab",
  20             action="store", type="string",
  21             dest="tab",
  22             help="The selected UI-tab when OK was pressed")
  23         self.OptionParser.add_option("--scale",
  24             action="store", type="string",
  25             dest="scale",
  26             help="The input (r,g,b) range")
  27
  28     def normalize(self, v):
  29         if v<0:
  30             return 0.0
  31         if v > float(self.options.scale):
  32             return float(self.options.scale)
  33         return v
  34
  35     def _hexstr(self,r,g,b):
  36         return '%02x%02x%02x' % (int(round(r)),int(round(g)),int(round(b)))
  37
  38     def colmod(self,_r,_g,_b):
  39         factor = 255.0/float(self.options.scale)
  40         r=float(_r)/factor
  41         g=float(_g)/factor
  42         b=float(_b)/factor
  43
  44         # add stuff to be accessible from within the custom color function here.
  45         safeenv = {'__builtins__':{},'r':r,'g':g,'b':b}
  46
  47         try:
  48             r2=self.normalize(eval(self.options.rFunction,safeenv))
  49             g2=self.normalize(eval(self.options.gFunction,safeenv))
  50             b2=self.normalize(eval(self.options.bFunction,safeenv))
  51         except:
  52             return self._hexstr(255.0,0.0,0.0)
  53         return self._hexstr(r2*factor,g2*factor,b2*factor)
  54
  55 c = C()
  56 c.affect()