[PATCH v6 1/5] drm: Add function to convert rect in 16.16 fixed format to regular format

[Souza, Jose]

On Tue, 2020-12-15 at 16:44 +0200, Ville Syrjälä wrote:
> On Mon, Dec 14, 2020 at 09:49:08AM -0800, José Roberto de Souza wrote:
> > Much more clear to read one function call than four lines doing this
> > conversion.
> > 
> > Cc: dri-devel at lists.freedesktop.org
> > Cc: Gwan-gyeong Mun <gwan-gyeong.mun at intel.com>
> > Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> > ---
> >  drivers/gpu/drm/drm_rect.c | 15 +++++++++++++++
> >  include/drm/drm_rect.h     |  2 ++
> >  2 files changed, 17 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/drm_rect.c b/drivers/gpu/drm/drm_rect.c
> > index 0460e874896e..24345704b353 100644
> > --- a/drivers/gpu/drm/drm_rect.c
> > +++ b/drivers/gpu/drm/drm_rect.c
> > @@ -373,3 +373,18 @@ void drm_rect_rotate_inv(struct drm_rect *r,
> >  	}
> >  }
> >  EXPORT_SYMBOL(drm_rect_rotate_inv);
> > +
> > +/**
> > + * drm_rect_convert_16_16_to_regular - Convert a rect in 16.16 fixed point form
> > + * to regular form.
> > + * @in: rect in 16.16 fixed point form
> > + * @out: rect to be stored the converted value
> > + */
> > +void drm_rect_convert_16_16_to_regular(struct drm_rect *in, struct drm_rect *out)
> > +{
> > +	out->x1 = in->x1 >> 16;
> > +	out->y1 = in->y1 >> 16;
> > +	out->x2 = in->x2 >> 16;
> > +	out->y2 = in->y2 >> 16;
> > +}
> 
> That's not the same as what we do in most places. We truncate
> the width/height, not x2/y2. Doing it on x2/y2 may increase
> the width/height.
> 
> So I suggest something more like:
> 
> static inline void drm_rect_fp_to_int(struct drm_rect *r)
> {
> 	drm_rect_init(r, r->x1 >> 16, r->y1 >> 16,
> 		      drm_rect_width(r) >> 16,
> 		      drm_rect_height(r) >> 16);
> }
> 
> to match the current way of doing things.

Okay, but most use cases takes drm_plane_state.src and converts and sets it in another rect, so will modify it to have two parameters.


>