[PATCH v4 1/3] libcamera: Add rectangle two-point constructor

[Jacopo Mondi]

Hello

On Mon, Sep 16, 2024 at 12:34:54PM GMT, Cheng-Hao Yang wrote:
> Hi Barnabás and Jacopo,
>
> On Mon, Sep 16, 2024 at 1:27 AM Barnabás Pőcze <pobrn at protonmail.com> wrote:
>
> > Hi
> >
> >
> > 2024. szeptember 5., csütörtök 10:35 keltezéssel, Jacopo Mondi <
> > jacopo.mondi at ideasonboard.com> írta:
> >
> > > Hi Barnabás
> > >
> > > On Wed, Sep 04, 2024 at 11:26:37AM GMT, Barnabás Pőcze wrote:
> > > > Hi
> > > >
> > > >
> > > > 2024. szeptember 3., kedd 13:39 keltezéssel, Harvey Yang <
> > chenghaoyang at chromium.org> írta:
> > > >
> > > > > From: Yudhistira Erlandinata <yerlandinata at chromium.org>
> > > > >
> > > > > Add a Rectangle constructor that accepts two points:
> > > > > topLeft and bottomRight.
> > > > >
> > > > > Signed-off-by: Yudhistira Erlandinata <yerlandinata at chromium.org>
> > > > > Co-developed-by: Harvey Yang <chenghaoyang at chromium.org>
> > > > > Reviewed-by: Jacopo Mondi <jacopo.mondi at ideasonboard.com>
> > > > > ---
> > > > >  include/libcamera/geometry.h |  2 ++
> > > > >  src/libcamera/geometry.cpp   | 14 ++++++++++++++
> > > > >  2 files changed, 16 insertions(+)
> > > > >
> > > > > diff --git a/include/libcamera/geometry.h
> > b/include/libcamera/geometry.h
> > > > > index 3e6f0f5d7..dc56f180f 100644
> > > > > --- a/include/libcamera/geometry.h
> > > > > +++ b/include/libcamera/geometry.h
> > > > > @@ -262,6 +262,8 @@ public:
> > > > >   {
> > > > >   }
> > > > >
> > > > > + constexpr Rectangle(const Point &topLeft, const Point
> > &bottomRight);
> > > >
> > > > Don't make this `constexpr` because it is not useful since the
> > definition is not available.
> > >
> > > I found references online that constexpr constuctors are implcitly
> > > inline, is this the reason of your comment ?
> >
> > Yes.
> >
> >
> > >
> > > However, I can't find it clearly specified in cppreference. Do you
> > > have any pointer ?
> >
> >   "A constexpr specifier used in a function or static data member(since
> > C++17) declaration implies inline."
> >   -- https://en.cppreference.com/w/cpp/language/constexpr
> >


One day I'll lear to read properly

> > >
> > > Anyway, if inline is the reason, isn't it better to inline the
> > > definition and maintain the constexpr specifier ?
> > > [...]
> >
> > That is an option as well.
> >
>
> IIUC, you're suggesting to put the definition of the new c'tor
> back in the header file? As we use `ASSERT` in this c'tor
> definition, there will be a compile error if we do that:
> ```
>
> In file included from ../include/libcamera/base/log.h:12,
>
>                  from ../include/libcamera/geometry.h:16,
>
>                  from ../include/libcamera/controls.h:21,
>
>                  from ../include/libcamera/camera.h:22,
>
>                  from ../src/apps/common/dng_writer.h:13,
>
>                  from ../src/apps/common/dng_writer.cpp:8:
>
> ../include/libcamera/base/private.h:21:2: error: #error "Private headers
> must not be included in the libcamera API"
>
>    21 | #error "Private headers must not be included in the libcamera API"
> ```

I see. log.h is private, and the fact ASSERT is not exposed in the
public API makes me think aborting execution on an invalid user input
is probably not the best idea ? That's maybe the reason why ASSERT is not
exposed to the public API ?

I'll ask others what they think about this
>
> BR,
> Harvey
>
>
> >
> > Regards,
> > Barnabás Pőcze
> >
> >