[PATCH] libcamera: geometry: Rename Rectangle's top-left corner

Umang Jain umang.jain at ideasonboard.com
Wed Sep 25 08:36:05 CEST 2024


Hi Jacopo

Thank you for the patch

On 24/09/24 6:15 pm, Jacopo Mondi wrote:
> The libcamera::Rectangle class should allow defining rectangles
> regardless of the reference system where an instance is used in.
>
> However the class documentation assumes the reference system origin
> point to be in the visual top-left side and that rectangles are
> constructed by specifying the top-left corner position and sizes.
>
> However this is ambiguous when using a different reference system as,
> in example, constructing a rectangle (x, y, w, h) in the following
> scenario, with the origin corner in the top-left position, would require
> a negative decrement along the y-axis.
>
>           ^
>           |
>          y|      o------------------
>           |      |                 | h
>           |      |                 |
>           |      -------------------
>           |               w
>            ------------------------------->
>           (0,0)  x
>
> To remove ambiguities, drop references to the visual top-left corner and
> define the rectangle's origin corner as the corner closer to the
> reference system origin point, and specify the horizontal and vertical
> dimensions always increment along their respective axis, as in the
> following example.
>
>           ^
>           |
>           |      -------------------
>           |      ^                 | h
>           |      |                 |
>          y|      o---->-------------
>           |               w
>            ------------------------------->
>           (0,0)  x
>
>           (0,0)  x
>             ------------------------------>
>            |              w
>           y|     o---->-------------
>            |     |                 | h
>            |     v                 |
>            |     -------------------
>            |
>            V
>
> Also rename for consistency the Rectangle::topLeft() function to
> Rectangle::origin() and update its in-tree users.
>
> Signed-off-by: Jacopo Mondi <jacopo.mondi at ideasonboard.com>
> ---
>   include/libcamera/geometry.h                  |  2 +-
>   src/ipa/ipu3/algorithms/af.cpp                |  2 +-
>   src/libcamera/geometry.cpp                    | 85 ++++++++++++++-----
>   .../pipeline/rpi/common/pipeline_base.cpp     |  4 +-
>   src/py/libcamera/py_geometry.cpp              |  2 +-
>   test/geometry.cpp                             |  8 +-
>   6 files changed, 75 insertions(+), 28 deletions(-)
>
> diff --git a/include/libcamera/geometry.h b/include/libcamera/geometry.h
> index 3e6f0f5d7fab..07cb0a7866fe 100644
> --- a/include/libcamera/geometry.h
> +++ b/include/libcamera/geometry.h
> @@ -277,7 +277,7 @@ public:
>   		return { width, height };
>   	}
>
> -	Point topLeft() const
> +	Point origin() const
>   	{
>   		return { x, y };
>   	}
> diff --git a/src/ipa/ipu3/algorithms/af.cpp b/src/ipa/ipu3/algorithms/af.cpp
> index cf68fb59c49b..1b707e9dd9ab 100644
> --- a/src/ipa/ipu3/algorithms/af.cpp
> +++ b/src/ipa/ipu3/algorithms/af.cpp
> @@ -155,7 +155,7 @@ int Af::configure(IPAContext &context, const IPAConfigInfo &configInfo)
>   	 * - Return the AF ROI as metadata in the Request
>   	 */
>   	Rectangle roi = gridSize.centeredTo(bds.center());
> -	Point start = roi.topLeft();
> +	Point start = roi.origin();
>
>   	/* x_start and y_start should be even */
>   	grid.x_start = utils::alignDown(start.x, 2);
> diff --git a/src/libcamera/geometry.cpp b/src/libcamera/geometry.cpp
> index 000151364c7f..45ba81a99920 100644
> --- a/src/libcamera/geometry.cpp
> +++ b/src/libcamera/geometry.cpp
> @@ -593,11 +593,39 @@ std::ostream &operator<<(std::ostream &out, const SizeRange &sr)
>    * \brief Describe a rectangle's position and dimensions
>    *
>    * Rectangles are used to identify an area of an image. They are specified by
> - * the coordinates of top-left corner and their horizontal and vertical size.
> + * the coordinates of the corner closer to the reference system's origin point
> + * and by horizontal and vertical increments from there.
>    *
> - * The measure unit of the rectangle coordinates and size, as well as the
> - * reference point from which the Rectangle::x and Rectangle::y displacements
> - * refers to, are defined by the context were rectangle is used.
> + * The corner closer to the reference system's origin point is the rectangle's
> + * origin corner.
> + *
> + * \verbatim
> +
> +  o = origin corner
> +
> +         ^
> +         |
> +         |      -------------------
> +         |      ^                 |
> +         |      |                 |
> +         |      o---->-------------
> +         |
> +          ------------------------------->
> +         (0,0)
> +
> +         (0,0)
> +           ------------------------------->
> +          |
> +          |      o---->-------------
> +          |      |                 |
> +          |      v                 |
> +          |      -------------------
> +          |
> +          V
> +   \endverbatim
> + *
> + * The measure unit of the rectangle coordinates and size are defined by the
> + * context were the rectangle is used.
>    */
>
>   /**
> @@ -608,35 +636,50 @@ std::ostream &operator<<(std::ostream &out, const SizeRange &sr)
>   /**
>    * \fn Rectangle::Rectangle(int x, int y, const Size &size)
>    * \brief Construct a Rectangle with the given position and size
> - * \param[in] x The horizontal coordinate of the top-left corner
> - * \param[in] y The vertical coordinate of the top-left corner
> + * \param[in] x The horizontal coordinate of the origin corner
> + * \param[in] y The vertical coordinate of the origin corner
>    * \param[in] size The size
> + *
> + * The rectangle's origin corner is the corner closer to the reference system
> + * origin point (0, 0).
>    */
>
>   /**
>    * \fn Rectangle::Rectangle(int x, int y, unsigned int width, unsigned int height)
>    * \brief Construct a Rectangle with the given position and size
> - * \param[in] x The horizontal coordinate of the top-left corner
> - * \param[in] y The vertical coordinate of the top-left corner
> + * \param[in] x The horizontal coordinate of the origin corner
> + * \param[in] y The vertical coordinate of the origin corner
>    * \param[in] width The width
>    * \param[in] height The height
> + *
> + * The rectangle's origin corner is the corner closer to the reference system
> + * origin point (0, 0).
>    */
>
>   /**
>    * \fn Rectangle::Rectangle(const Size &size)
> - * \brief Construct a Rectangle of \a size with its top left corner located
> + * \brief Construct a Rectangle of \a size with its origin corner located
>    * at (0,0)
>    * \param[in] size The desired Rectangle size
> + *
> + * The rectangle's origin corner is the corner closer to the reference system
> + * origin point (0, 0).
>    */
>
>   /**
>    * \var Rectangle::x
> - * \brief The horizontal coordinate of the rectangle's top-left corner
> + * \brief The horizontal coordinate of the rectangle's origin corner
> + *
> + * The rectangle's origin corner is the corner closer to the reference system
> + * origin point (0, 0).
>    */
>
>   /**
>    * \var Rectangle::y
> - * \brief The vertical coordinate of the rectangle's top-left corner
> + * \brief The vertical coordinate of the rectangle's origin corner
> + *
> + * The rectangle's origin corner is the corner closer to the reference system
> + * origin point (0, 0).
>    */
>
>   /**
> @@ -683,9 +726,13 @@ Point Rectangle::center() const
>    */
>
>   /**
> - * \fn Point Rectangle::topLeft() const
> - * \brief Retrieve the coordinates of the top left corner of this Rectangle
> - * \return The Rectangle's top left corner
> + * \fn Point Rectangle::origin() const
> + * \brief Retrieve the coordinates of the origin corner of this Rectangle
> + *
> + * The rectangle's origin corner is the corner closer to the reference system
> + * origin point (0, 0).
> + *
> + * \return The Rectangle's origin corner

I think you can drop "corner" from "origin corner"

Probably throughout the patch:
     s/origin corner/origin/

Otherwise, LGTM

Reviewed-by: Umang Jain <umang.jain at ideasonboard.com>
>    */
>
>   /**
> @@ -740,15 +787,15 @@ Rectangle &Rectangle::translateBy(const Point &point)
>    */
>   Rectangle Rectangle::boundedTo(const Rectangle &bound) const
>   {
> -	int topLeftX = std::max(x, bound.x);
> -	int topLeftY = std::max(y, bound.y);
> +	int originX = std::max(x, bound.x);
> +	int originY = std::max(y, bound.y);
>   	int bottomRightX = std::min<int>(x + width, bound.x + bound.width);
>   	int bottomRightY = std::min<int>(y + height, bound.y + bound.height);
>
> -	unsigned int newWidth = std::max(bottomRightX - topLeftX, 0);
> -	unsigned int newHeight = std::max(bottomRightY - topLeftY, 0);
> +	unsigned int newWidth = std::max(bottomRightX - originX, 0);
> +	unsigned int newHeight = std::max(bottomRightY - originY, 0);
>
> -	return { topLeftX, topLeftY, newWidth, newHeight };
> +	return { originX, originY, newWidth, newHeight };
>   }
>
>   /**
> diff --git a/src/libcamera/pipeline/rpi/common/pipeline_base.cpp b/src/libcamera/pipeline/rpi/common/pipeline_base.cpp
> index 3041fd1ed9fd..8d2440026689 100644
> --- a/src/libcamera/pipeline/rpi/common/pipeline_base.cpp
> +++ b/src/libcamera/pipeline/rpi/common/pipeline_base.cpp
> @@ -1289,7 +1289,7 @@ Rectangle CameraData::scaleIspCrop(const Rectangle &ispCrop) const
>   	 */
>   	Rectangle nativeCrop = ispCrop.scaledBy(sensorInfo_.analogCrop.size(),
>   						sensorInfo_.outputSize);
> -	nativeCrop.translateBy(sensorInfo_.analogCrop.topLeft());
> +	nativeCrop.translateBy(sensorInfo_.analogCrop.origin());
>   	return nativeCrop;
>   }
>
> @@ -1303,7 +1303,7 @@ void CameraData::applyScalerCrop(const ControlList &controls)
>   			nativeCrop = { 0, 0, 1, 1 };
>
>   		/* Create a version of the crop scaled to ISP (camera mode) pixels. */
> -		Rectangle ispCrop = nativeCrop.translatedBy(-sensorInfo_.analogCrop.topLeft());
> +		Rectangle ispCrop = nativeCrop.translatedBy(-sensorInfo_.analogCrop.origin());
>   		ispCrop.scaleBy(sensorInfo_.outputSize, sensorInfo_.analogCrop.size());
>
>   		/*
> diff --git a/src/py/libcamera/py_geometry.cpp b/src/py/libcamera/py_geometry.cpp
> index c7e303609427..8dee365b25dd 100644
> --- a/src/py/libcamera/py_geometry.cpp
> +++ b/src/py/libcamera/py_geometry.cpp
> @@ -105,7 +105,7 @@ void init_py_geometry(py::module &m)
>   		.def_property_readonly("is_null", &Rectangle::isNull)
>   		.def_property_readonly("center", &Rectangle::center)
>   		.def_property_readonly("size", &Rectangle::size)
> -		.def_property_readonly("topLeft", &Rectangle::topLeft)
> +		.def_property_readonly("origin", &Rectangle::origin)
>   		.def("scale_by", &Rectangle::scaleBy)
>   		.def("translate_by", &Rectangle::translateBy)
>   		.def("bounded_to", &Rectangle::boundedTo)
> diff --git a/test/geometry.cpp b/test/geometry.cpp
> index 64169206ad16..a4ee6f6e167a 100644
> --- a/test/geometry.cpp
> +++ b/test/geometry.cpp
> @@ -363,16 +363,16 @@ protected:
>   			return TestFail;
>   		}
>
> -		/* Rectangle::size(), Rectangle::topLeft() and Rectangle::center() tests */
> +		/* Rectangle::size(), Rectangle::origin() and Rectangle::center() tests */
>   		if (Rectangle(-1, -2, 3, 4).size() != Size(3, 4) ||
>   		    Rectangle(0, 0, 100000, 200000).size() != Size(100000, 200000)) {
>   			cout << "Rectangle::size() test failed" << endl;
>   			return TestFail;
>   		}
>
> -		if (Rectangle(1, 2, 3, 4).topLeft() != Point(1, 2) ||
> -		    Rectangle(-1, -2, 3, 4).topLeft() != Point(-1, -2)) {
> -			cout << "Rectangle::topLeft() test failed" << endl;
> +		if (Rectangle(1, 2, 3, 4).origin() != Point(1, 2) ||
> +		    Rectangle(-1, -2, 3, 4).origin() != Point(-1, -2)) {
> +			cout << "Rectangle::origin() test failed" << endl;
>   			return TestFail;
>   		}
>
> --
> 2.46.1
>



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