tabakrolletjie/transforms.py

   1 """ Image transformations for use with the image loader. """
   2
   3 import pygame.surface
   4
   5
   6 class Transform(object):
   7
   8     ARGS = []
   9
  10     def __init__(self, **kw):
  11         for k in self.ARGS:
  12             setattr(self, k, kw.pop(k))
  13         assert not kw
  14         self._repr = "%s: <%s>" % (
  15             self.__class__.__name__,
  16             ", ".join("%s=%s" % (k, getattr(self, k)) for k in self.ARGS))
  17         return
  18
  19     def __repr__(self):
  20         return self._repr
  21
  22     def __hash__(self):
  23         return hash(self._repr)
  24
  25     def __eq__(self, other):
  26         if not isinstance(other, Transform):
  27             return NotImplemented
  28         return self._repr == other._repr
  29
  30     def apply(self, surface):
  31         raise NotImplementedError("Transforms should implement .apply")
  32
  33
  34 class NullTransform(Transform):
  35     """ Do nothing. """
  36
  37     def apply(self, surface):
  38         return surface
  39
  40
  41 class Overlay(Transform):
  42     """ Apply a colour overlay. """
  43
  44     ARGS = ["colour"]
  45
  46     def apply(self, surface):
  47         over = pygame.surface.Surface(surface.get_size())
  48         over = over.convert_alpha()
  49         over.fill(self.colour)
  50         surface.blit(over, (0, 0), None)
  51         return surface