Re: Image transformations

[Eli Zaretskii]

> Date: Thu, 27 Jun 2019 12:37:15 +0900
> From: YAMAMOTO Mitsuharu <address@hidden>
> Cc: address@hidden,
>       address@hidden
> 
> > > Guessing from its API design, I think GDI does not internally perform
> > > any (real-valued) matrix calculations, but uses some variant of
> > > Bresenham's line algorithm for image transformations to prefer integer
> > > arithmetics.
> > 
> > I think the fact that SetWorldTransform exists contradicts this
> > conclusion.  The matrix is defined as an array of floats.
> 
> It seems that SetWorldTransform is only effective on vector drawings,
> but not on bitmap image drawings.

My conclusion was different, because I saw examples of using
SetWorldTransform to rotate bitmap images.  But I don't think it's
important enough to argue about, as we both are just guessing.