recent changes

[Jonathan Coles]

here's a summary of the changes i just checked in:

	o Assume that a mask should always be applied to a layer
	  unless the user explicitly turns it off. The flag is
	  *not* saved, however.

	o Instead of returning the mask as RGB triples, it suffices
	  to create a bit array that can be used to create a bitmap
	  using wxBitmapFromBits(). This reduces the amount of 
	  memory and also eliminates the need to first convert the
	  mask to a wxImage and then to a wxBitmap.

	o Support for alpha blending only exists at the C++ level,
	  although the alpha channel can be requested from the python
	  level, but isn't. wxWidgets >=2.5 supports alpha blending,
	  but the actually python drawing code hasn't been changed to 
	  support it. It should be possible to determine if alpha
	  support is available and use it if the user wants to.

--jonathan

-- 
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 Jonathan Coles                               http://www.jpcoles.com
 jonathan at jpcoles.com                    GnuPG Key: /gpg_pub_key.asc
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