[comp.sys.sgi] Blending images

tjh@bucrf11.bu.edu (Tim Hall) (03/04/91)

When doing a "rectcopy" are the alpha values copied along with the
RGB values?  If so, is compositing done if the "blendfunction" has
been specified?  Just curious.....

-- 
-Tim Hall
tjh@bu-pub.bu.edu

The night is filled with the cries of dispossessed children in search
of paradise.  -Dead Can Dance

rad@home.asd.sgi.com (Bob Drebin) (03/05/91)

In article <76041@bu.edu.bu.edu>, tjh@bucrf11.bu.edu (Tim Hall) writes:
|> When doing a "rectcopy" are the alpha values copied along with the
|> RGB values?  If so, is compositing done if the "blendfunction" has
|> been specified?  Just curious.....
|> 
|> -- 
|> -Tim Hall
|> tjh@bu-pub.bu.edu
|> 
|> The night is filled with the cries of dispossessed children in search
|> of paradise.  -Dead Can Dance

Yes alpha values are copied during rectcopies, and the source rectangle
is combined with the destination rectangle using the current blendfunction
or logic-op.