| Re: [AD] Optimized rotation routine |
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Laurence Withers wrote:
> In reply to Sven Sandberg <ssven.geo@xxxxxxxxxx>:
> >Also, what is sensible to do when scale<0 in
> >`rotate_scaled_sprite()' & co? Draw flipped or
don't
> >draw at all?
>
> In math, a negative scale factor means that the
> object being enlarged is rotated by pi around the
> origin of the enlargement before actually being
> enlarged.
Yup, which is the same as flipping it in the centre
point, which is the same as flipping it around both
axes, which is what Allegro does. I'll keep that
behaviour.
Does anyone have any strong feelings whether the
scanline drawers for rotating between different color
depths and different kinds of bitmaps should be
included? Otherwise I'll include them.
Also, I'll remove `rotate_scaled_sprite_flip()' if
nobody objects, since (1) it's sort of inconsistent
with the rest of the API, (2) it's trivial to do the
same thing in terms of the other functions (and
allegro.txt explains how), and (3) it's currently not
in allegro.h, so nobody uses it.
Sven
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