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Diffstat (limited to 'src/libcamera/orientation.cpp')
-rw-r--r-- | src/libcamera/orientation.cpp | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/src/libcamera/orientation.cpp b/src/libcamera/orientation.cpp new file mode 100644 index 00000000..a3465383 --- /dev/null +++ b/src/libcamera/orientation.cpp @@ -0,0 +1,98 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * Copyright (C) 2023, Ideas On Board Oy + * + * orientation.cpp - Image orientation + */ + +#include <libcamera/orientation.h> + +#include <array> +#include <string> + +/** + * \file libcamera/orientation.h + * \brief Image orientation definition + */ + +namespace libcamera { + +/** + * \enum Orientation + * \brief The image orientation in a memory buffer + * + * The Orientation enumeration describes the orientation of the images + * produced by the camera pipeline as they get received by the application + * inside memory buffers. + * + * The image orientation expressed using the Orientation enumeration can be then + * inferred by applying to a naturally oriented image a multiple of a 90 degrees + * rotation in the clockwise direction from the origin and then by applying an + * optional horizontal mirroring. + * + * The enumeration numerical values follow the ones defined by the EXIF + * Specification version 2.32, Tag 274 "Orientation", while the names of the + * enumerated values report the rotation and mirroring operations performed. + * + * For example, Orientation::Rotate90Mirror describes the orientation obtained + * by rotating the image 90 degrees clockwise first and then applying a + * horizontal mirroring. + */ + +/** + * \brief Return the orientation representing a rotation of the given angle + * clockwise + * \param[in] angle The angle of rotation in a clockwise sense. Negative values + * can be used to represent anticlockwise rotations + * \param[out] success Set to `true` if the angle is a multiple of 90 degrees, + * otherwise `false` + * \return The orientation corresponding to the rotation if \a success was set + * to `true`, otherwise the `Rotate0` orientation + */ +Orientation orientationFromRotation(int angle, bool *success) +{ + angle = angle % 360; + if (angle < 0) + angle += 360; + + if (success != nullptr) + *success = true; + + switch (angle) { + case 0: + return Orientation::Rotate0; + case 90: + return Orientation::Rotate90; + case 180: + return Orientation::Rotate180; + case 270: + return Orientation::Rotate270; + } + + if (success != nullptr) + *success = false; + + return Orientation::Rotate0; +} + +/** + * \brief Prints human-friendly names for Orientation items + * \param[in] out The output stream + * \param[in] orientation The Orientation item + * \return The output stream \a out + */ +std::ostream &operator<<(std::ostream &out, const Orientation &orientation) +{ + constexpr std::array<const char *, 9> orientationNames = { + "", /* Orientation starts counting from 1. */ + "Rotate0", "Rotate0Mirror", + "Rotate180", "Rotate180Mirror", + "Rotate90Mirror", "Rotate270", + "Rotate270Mirror", "Rotate90", + }; + + out << orientationNames[static_cast<unsigned int>(orientation)]; + return out; +} + +} /* namespace libcamera */ |