[libcamera-devel] [PATCH 2/3] ipa: ipu3: af: Use geometry classes to perform grid centering

[Kieran Bingham]

Quoting Laurent Pinchart (2022-03-23 01:22:44)
> Hi Kieran,
> 
> Thank you for the patch.
> 
> On Tue, Mar 15, 2022 at 05:53:44PM +0000, Kieran Bingham via libcamera-devel wrote:
> > Use our geometry classes for Rectangle, Size and Point to identify
> > the region of interest for the autofocus, and center it on the BDS output.
> > 
> > This will facilitate custom ROI being passed in through controls at a later
> > time.
> > 
> > Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> > ---
> >  src/ipa/ipu3/algorithms/af.cpp | 24 ++++++++++++++++--------
> >  1 file changed, 16 insertions(+), 8 deletions(-)
> > 
> > diff --git a/src/ipa/ipu3/algorithms/af.cpp b/src/ipa/ipu3/algorithms/af.cpp
> > index 3cedf8cbd687..469762a29937 100644
> > --- a/src/ipa/ipu3/algorithms/af.cpp
> > +++ b/src/ipa/ipu3/algorithms/af.cpp
> > @@ -141,16 +141,24 @@ int Af::configure(IPAContext &context, const IPAConfigInfo &configInfo)
> >       grid.block_height_log2 = kAfMinGridBlockHeight;
> >       grid.height_per_slice = kAfDefaultHeightPerSlice;
> >  
> > -     /* x_start and y start are default to BDS center */
> > -     grid.x_start = (configInfo.bdsOutputSize.width / 2) -
> > -                    (((grid.width << grid.block_width_log2) / 2));
> > -     grid.y_start = (configInfo.bdsOutputSize.height / 2) -
> > -                    (((grid.height << grid.block_height_log2) / 2));
> > +     /* Position the AF grid in the center of the BDS output. */
> > +     Rectangle bds(configInfo.bdsOutputSize);
> > +     Size gridSize(grid.width << grid.block_width_log2,
> > +                   grid.height << grid.block_height_log2);
> > +
> > +     /*
> > +      * \todo - Support request metadata
> > +      * - Set the ROI based on any input controls in the request
> > +      * - Return the AF ROI as metadata in the Request
> > +      * - Provide an alignedTo on a point, or Rectangle x,y position
> > +      */
> > +     Rectangle roi = gridSize.centeredTo(bds.center());
> > +     Point start = roi.topLeft();
> >  
> >       /* x_start and y_start should be even */
> > -     grid.x_start = (grid.x_start / 2) * 2;
> > -     grid.y_start = (grid.y_start / 2) * 2;
> > -     grid.y_start = grid.y_start | IPU3_UAPI_GRID_Y_START_EN;
> > +     grid.x_start = (start.x / 2) * 2;
> > +     grid.y_start = (start.y / 2) * 2;
> 
> You could use
> 
>         grid.x_start = utils::alignDown(start.x, 2);
>         grid.y_start = utils::alignDown(start.y, 2);

Thanks, that's what I want. I was looking for a way to align a Point (or
Rectangle x,y) to a specific value in geometry, didn't think to look for
it in utils.

> 
> or possibly even
> 
>         grid.x_start = start.x & ~1;
>         grid.y_start = start.y & ~1;
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> 
> > +     grid.y_start |= IPU3_UAPI_GRID_Y_START_EN;
> >  
> >       /* Initial max focus step */
> >       maxStep_ = kMaxFocusSteps;
> 
> -- 
> Regards,
> 
> Laurent Pinchart