Re: [AD] blender operations SRC and DST

[Jon Rafkind <workmin@xxxxxxxxxx>]

On 06/09/2011 07:26 PM, Peter Wang wrote:
> On 2011-06-09, Jon Rafkind <workmin@xxxxxxxxxx> wrote:
>>> I checked it quickly in ex_blend2 but the results are different for
>>> textures and memory bitmaps.  I don't know what its supposed to look
>>> like.
>>>
>> I checked a couple of different modes, texture and memory bitmaps look
>> the same to me. Can you take a screenshot when you see a difference?
> Attached one.  Also there is an assertion failure when either of the
> alpha blenders is set to SRC_COLOR or DST_COLOR.  I didn't look into it
> yet.
>
> include/allegro5/internal/aintern_blend.h:37: get_alpha_factor: Assertion `0' failed.
>

Oh.. its because the primitives addon sets up its own blending and
doesn't take SRC_COLOR or DST_COLOR into account. Probably if there is
this level of sharing the blending code should be made public and the
primitives addon can just call it.

prim_opengl.c:setup_blending

I think I could remove that assert about the alpha factor not
recognizing SRC_COLOR and DST_COLOR. For the alpha blenders they should
just use the src->a or dst->a as appropriate.