[1/4] gid32: Add matrix helper functions.

[Ralf Habacker]

> On 1/7/2014 17:31, Ralf Habacker wrote:
> > Contains basic functions required by further patches
> >
> > dlls/gdi32/dibdrv/graphics.c | 49
> > ++++++++++++++++++++++++++++++++++++++++++++
> >   1 file changed, 49 insertions(+)
>
> That should be merged with a first patch that uses it.

done   http://www.winehq.org/pipermail/wine-patches/2014-January/129505.html
> > +/*
> > - check matrix for condition
> >
> > +*/
> > +BOOL hasRotatedAndSameScaledMatrixOnly(XFORM *xform)
> > +{
> > - return xform->eM11 == xform->eM22 &&
> > -
> >      -xform->eM21 == xform->eM12;
> >
> > +}
> > -
>
> Comment is telling nothing, 'xform' should be const probably.

done, see above link
> > - double determinant = 0;
> > -
> > - /* xform = xfrom-transposed * xform */
> > - xform->eM11 = sqrt( xform->eM11 * xform->eM11 + xform->eM21 *

xform->eM21 );
> > - xform->eM22 = sqrt( xform->eM12 * xform->eM12 + xform->eM22 *

xform->eM22 );
> > - xform->eM12 = 0;
> > - xform->eM21 = 0;
> > - xform->eDx = 0;
> > - xform->eDy = 0;
> > -
> > - if ( rotation_and_translation == NULL )
> > -
> >    return TRUE;
> > -
> > - determinant = xform->eM11 * xform->eM22;
> > -
> > - inverse_matrix_scale.eM11 = xform->eM22 / determinant;
>
> Is it possible to get 0 determinant here? Function never returns FALSE,
> so return value is useless.

fixed in above mentioned file.
> Also please follow function and variable naming conventions used in this
> file.

done, found also better names for this functions.

Regards
 Ralf