[libcamera-devel] [PATCH 1/2] libcamera: geometry: Add Size members to grown or shrink by a margin

Laurent Pinchart laurent.pinchart at ideasonboard.com
Wed Oct 13 10:00:44 CEST 2021


Hi Jacopo,

On Wed, Oct 13, 2021 at 08:36:48AM +0200, Jacopo Mondi wrote:
> On Wed, Oct 13, 2021 at 04:26:29AM +0300, Laurent Pinchart wrote:
> > Add four new member functions to the Size class (two in-place and two
> > const) to grow and shrink a Size by given margins.
> >
> > Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> > ---
> >  include/libcamera/geometry.h | 30 ++++++++++++++++++++++
> >  src/libcamera/geometry.cpp   | 42 +++++++++++++++++++++++++++++++
> >  test/geometry.cpp            | 48 ++++++++++++++++++++++++++++++++----
> >  3 files changed, 115 insertions(+), 5 deletions(-)
> >
> > diff --git a/include/libcamera/geometry.h b/include/libcamera/geometry.h
> > index fdd1b4678074..fa7ae7bce8db 100644
> > --- a/include/libcamera/geometry.h
> > +++ b/include/libcamera/geometry.h
> > @@ -94,6 +94,20 @@ public:
> >  		return *this;
> >  	}
> >
> > +	Size &growBy(const Size &margins)
> > +	{
> > +		width += margins.width;
> > +		height += margins.height;
> > +		return *this;
> > +	}
> > +
> > +	Size &shrinkBy(const Size &margins)
> > +	{
> > +		width = width > margins.width ? width - margins.width : 0;
> > +		height = height > margins.height ? height - margins.height : 0;
> 
> I was about to suggest std::max(height - margins.height, 0u) but it
> doesn't work well with unsigned ints.

I've thought the same and considered playing with casts, but the result
was worse.

> Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>
> 
> > +		return *this;
> > +	}
> > +
> >  	__nodiscard constexpr Size alignedDownTo(unsigned int hAlignment,
> >  						 unsigned int vAlignment) const
> >  	{
> > @@ -128,6 +142,22 @@ public:
> >  		};
> >  	}
> >
> > +	__nodiscard constexpr Size grownBy(const Size &margins) const
> > +	{
> > +		return {
> > +			width + margins.width,
> > +			height + margins.height
> > +		};
> > +	}
> > +
> > +	__nodiscard constexpr Size shrunkBy(const Size &margins) const
> > +	{
> > +		return {
> > +			width > margins.width ? width - margins.width : 0,
> > +			height > margins.height ? height - margins.height : 0
> > +		};
> > +	}
> > +
> >  	__nodiscard Size boundedToAspectRatio(const Size &ratio) const;
> >  	__nodiscard Size expandedToAspectRatio(const Size &ratio) const;
> >
> > diff --git a/src/libcamera/geometry.cpp b/src/libcamera/geometry.cpp
> > index b014180e9ba5..cb3c2de18d5e 100644
> > --- a/src/libcamera/geometry.cpp
> > +++ b/src/libcamera/geometry.cpp
> > @@ -173,6 +173,28 @@ const std::string Size::toString() const
> >   * \return A reference to this object
> >   */
> >
> > +/**
> > + * \fn Size::growBy(const Size &margins)
> > + * \brief Grow the size by \a margins in place
> > + * \param[in] margins The margins to add to the size
> > + *
> > + * This function adds the width and height of the \a margin size to this size.
> > + *
> > + * \return A reference to this object
> > + */
> > +
> > +/**
> > + * \fn Size::shrinkBy(const Size &margins)
> > + * \brief Shrink the size by \a margins in place
> > + * \param[in] margins The margins to subtract to the size
> > + *
> > + * This function subtracts the width and height of the \a margin size from this
> > + * size. If the width or height of the size are smaller than those of \a
> > + * margins, the result is clamped to 0.
> > + *
> > + * \return A reference to this object
> > + */
> > +
> >  /**
> >   * \fn Size::alignedDownTo(unsigned int hAlignment, unsigned int vAlignment)
> >   * \brief Align the size down horizontally and vertically
> > @@ -209,6 +231,26 @@ const std::string Size::toString() const
> >   * height of this size and the \a expand size
> >   */
> >
> > +/**
> > + * \fn Size::grownBy(const Size &margins)
> > + * \brief Grow the size by \a margins
> > + * \param[in] margins The margins to add to the size
> > + * \return A Size whose width and height are the sum of the width and height of
> > + * this size and the \a margins size
> > + */
> > +
> > +/**
> > + * \fn Size::shrunkBy(const Size &margins)
> > + * \brief Shrink the size by \a margins
> > + * \param[in] margins The margins to subtract to the size
> > + *
> > + * If the width or height of the size are smaller than those of \a margins, the
> > + * resulting size has its width or height clamped to 0.
> > + *
> > + * \return A Size whose width and height are the difference of the width and
> > + * height of this size and the \a margins size, clamped to 0
> > + */
> > +
> >  /**
> >   * \brief Bound the size down to match the aspect ratio given by \a ratio
> >   * \param[in] ratio The size whose aspect ratio must be matched
> > diff --git a/test/geometry.cpp b/test/geometry.cpp
> > index d13c88bf2e40..5125692496b3 100644
> > --- a/test/geometry.cpp
> > +++ b/test/geometry.cpp
> > @@ -104,7 +104,10 @@ protected:
> >  			return TestFail;
> >  		}
> >
> > -		/* Test alignDownTo(), alignUpTo(), boundTo() and expandTo() */
> > +		/*
> > +		 * Test alignDownTo(), alignUpTo(), boundTo(), expandTo(),
> > +		 * growBy() and shrinkBy()
> > +		 */
> >  		Size s(50, 50);
> >
> >  		s.alignDownTo(16, 16);
> > @@ -131,14 +134,36 @@ protected:
> >  			return TestFail;
> >  		}
> >
> > -		s.alignDownTo(16, 16).alignUpTo(32, 32)
> > -		 .boundTo({ 40, 80 }).expandTo({ 16, 80 });
> > -		if (s != Size(40, 80)) {
> > +		s.growBy({ 10, 20 });
> > +		if (s != Size(60, 70)) {
> > +			cout << "Size::growBy() test failed" << endl;
> > +			return TestFail;
> > +		}
> > +
> > +		s.shrinkBy({ 20, 10 });
> > +		if (s != Size(40, 60)) {
> > +			cout << "Size::shrinkBy() test failed" << endl;
> > +			return TestFail;
> > +		}
> > +
> > +		s.shrinkBy({ 100, 100 });
> > +		if (s != Size(0, 0)) {
> > +			cout << "Size::shrinkBy() clamp test failed" << endl;
> > +			return TestFail;
> > +		}
> > +
> > +		s = Size(50,50).alignDownTo(16, 16).alignUpTo(32, 32)
> > +		  .boundTo({ 40, 80 }).expandTo({ 16, 80 })
> > +		  .growBy({ 4, 4 }).shrinkBy({ 10, 20 });
> > +		if (s != Size(34, 64)) {
> >  			cout << "Size chained in-place modifiers test failed" << endl;
> >  			return TestFail;
> >  		}
> >
> > -		/* Test alignedDownTo(), alignedUpTo(), boundedTo() and expandedTo() */
> > +		/*
> > +		 * Test alignedDownTo(), alignedUpTo(), boundedTo(),
> > +		 * expandedTo(), grownBy() and shrunkBy()
> > +		 */
> >  		if (Size(0, 0).alignedDownTo(16, 8) != Size(0, 0) ||
> >  		    Size(1, 1).alignedDownTo(16, 8) != Size(0, 0) ||
> >  		    Size(16, 8).alignedDownTo(16, 8) != Size(16, 8)) {
> > @@ -167,6 +192,19 @@ protected:
> >  			return TestFail;
> >  		}
> >
> > +		if (Size(0, 0).grownBy({ 10, 20 }) != Size(10, 20) ||
> > +		    Size(200, 50).grownBy({ 10, 20 }) != Size(210, 70)) {
> > +			cout << "Size::grownBy() test failed" << endl;
> > +			return TestFail;
> > +		}
> > +
> > +		if (Size(200, 50).shrunkBy({ 10, 20 }) != Size(190, 30) ||
> > +		    Size(200, 50).shrunkBy({ 10, 100 }) != Size(190, 0) ||
> > +		    Size(200, 50).shrunkBy({ 300, 20 }) != Size(0, 30)) {
> > +			cout << "Size::shrunkBy() test failed" << endl;
> > +			return TestFail;
> > +		}
> > +
> >  		/* Aspect ratio tests */
> >  		if (Size(0, 0).boundedToAspectRatio(Size(4, 3)) != Size(0, 0) ||
> >  		    Size(1920, 1440).boundedToAspectRatio(Size(16, 9)) != Size(1920, 1080) ||

-- 
Regards,

Laurent Pinchart


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