Re: [PATCH] winex11.drv: Fix incorrect frequency for doublescan and interlaced modes.

[Zhiyi Zhang]

On 2/4/20 4:27 PM, Dmitry Timoshkov wrote:
> Zhiyi Zhang  wrote:
> > +static DWORD get_frequency( const XRRModeInfo *mode )
> > +{
> > - if (mode->hTotal && mode->vTotal)
> > - {
> > -
> >    double v_total = mode->vTotal;
> > -
> > -
> >    if (mode->modeFlags & RR_DoubleScan)
> > -
> >        v_total *= 2;
> > -
> >    if (mode->modeFlags & RR_Interlace)
> > -
> >        v_total /= 2;
> > -
> > -
> >    /* Adding 0.05 instead of 0.5 to round so that common frequencies like
> > -
> >     * 59.94Hz and 23.976Hz become 59Hz and 24Hz. Using 0.5 would make
> > -
> >     * 59.94Hz become 60Hz and would make it seem like there are two 60Hz modes */
> > -
> >    return mode->dotClock / (mode->hTotal * v_total) + 0.05;
> > - }
> > -
> > - return 0;
> >
> > +}
>
> It seems that floating point (and especially double) is not needed here
> to do a proper calculation.

It's needed. See https://gitlab.freedesktop.org/xorg/app/xrandr/commit/00c795e99fe29ecd56e05e...