adamdruppe: Drawing scaled image

[Pie? via Digitalmars-d-learn]

I found your git hub and tried simpledisplay and png. I had 
virtually no problems getting them working from the get go! 
Thanks for your hard work!!! You deserve a cookie, or a million 
bucks!

I'm curious about how to draw a scaled image. I would like to 
have a "global" scale for my image drawing. Is there a way to 
apply a global transform efficiently?(not all image drawing 
though, just some).

Also, png.d doesn't seem to work with alpha channel? I did a 
quick "alpha" search and simpledisplay.d says it doesn't work 
with alpha yet, except for openGL.

How hard would this be to add? Obviously it requires composting 
the underlying bits. I will be working on a buffer for all window 
drawing, one large non-alpha bitmap that I draw everything to, 
hence it should be somewhat fast to compose.

Which also leads me to, how to draw one image on to another?

Basically I want to setup a sort of triple buffer(if necessary, 
or just single) sprite rendering engine(well, not really but it's 
equivalent to it).

Is simple display and png capable of doing this without too much 
trouble?