Marcus von Appen wrote:
On, Wed Apr 16, 2008, Lenard Lindstrom wrote:
I was trying out BLEND_ADD with blit to see if an alpha plane could be
added to a surface with alpha's zero. Here is the trial session:
[...]
Both surfaces contain alpha, so only alpha blending will be applied. The
BLEND_* args only work for cases where alpha blending cannot be
applied.
Should we change this to take alpha into account for the BLEND_* args as
well and only apply the default alpha blending, if no BLEND_* args are
passed?
The documentation is vague on this. It just says that BLEND_ flags are
optional. Nothing is mentioned about them being ignored. For alpha
surfaces a blend may be useful for doing shadow effects. Such effects
require extracting and altering the alpha plane. Want to make a shadow
for antialiased text. Extract the alpha and apply to an all black
surface. Right now surfarray must be used to do this in a practical way.
Otherwise it would have to be done per-pixel with get_at/set_at.
--
Lenard Lindstrom
<[EMAIL PROTECTED]>
