[PD-dev] [GEM] CVS-changes

[chris clepper]

>and another two changes:
>
>1. [alpha]
>now you can set the blending-function
>0..GL_ONE_MINUS_SRC_ALPHA that's the (old) default
>1..GL_ONE (as would be enabled by the "blend" message to various objects.

perhaps we should add some of the other options for glBlend and allow 
both the source and destination to be changed.

>2. [polygon_smooth]
>enables polygon smoothing
>
>i think this is better than having to add the "blend" method to all Geos.
>So users can decide what they need. (and they need to know about it anyhow)

the only difference i found is that [polygon_smooth] sets blending 
for the entire render chain it's attached to while the "blend" method 
would actually work on individual objects in the same chain.  it's 
probably not a big deal, and maybe not even a big feature to warrant 
keeping "blend".  it's definitely easier to do the [polygon_smooth] 
rather than add glBlend to each Geo.

>i think [polygon_smooth] is a bad name. but which one would be better ?

still no suggestions for the name...  maybe wrapping [alpha], [color] 
and [polygon_smooth] up in an abstraction called [geo_blend] would be 
something to try?

cgc