File indexing completed on 2025-01-05 03:56:30

 /* ============================================================
  *
  * This file is a part of digiKam project
  * https://www.digikam.org
  *
  * Date        : 2006-09-15
  * Description : Exiv2 library interface.
  *               Tools for combining rotation operations.
  *
  * SPDX-FileCopyrightText: 2006-2024 by Gilles Caulier <caulier dot gilles at gmail dot com>
  * SPDX-FileCopyrightText: 2006-2013 by Marcel Wiesweg <marcel dot wiesweg at gmx dot de>
  *
  * SPDX-License-Identifier: GPL-2.0-or-later
  *
  * ============================================================ */
 
 #ifndef META_ENGINE_ROTATION_H
 #define META_ENGINE_ROTATION_H
 
 // Qt includes
 
 #include <QTransform>
 
 // Local includes
 
 #include "digikam_export.h"
 #include "metaengine.h"
 
 namespace Digikam
 {
 
 class DIGIKAM_EXPORT MetaEngineRotation
 {
 
 public:
 
     /**
      * This describes single transform primitives.
      * Note some of the defined Exif rotation flags combine
      * two of these actions.
      * The enum values correspond to those defined
      * as JXFORM_CODE in the often used the JPEG tool transupp.h.
      */
     enum TransformationAction
     {
         NoTransformation = 0, ///< no transformation
         FlipHorizontal   = 1, ///< horizontal flip
         FlipVertical     = 2, ///< vertical flip
         Rotate90         = 5, ///< 90-degree clockwise rotation
         Rotate180        = 6, ///< 180-degree rotation
         Rotate270        = 7  ///< 270-degree clockwise (or 90 ccw)
     };
 
 public:
 
     /**
      * Constructs the identity matrix (the matrix describing no transformation)
      */
     MetaEngineRotation();
 
     /**
      * Returns the matrix corresponding to the given TransformationAction
      */
     explicit MetaEngineRotation(TransformationAction action);
 
     /**
      * Returns the matrix corresponding to the given TransformationAction
      */
     explicit MetaEngineRotation(MetaEngine::ImageOrientation exifOrientation);
 
     bool operator==(const MetaEngineRotation& ma)   const;
     bool operator!=(const MetaEngineRotation& ma)   const;
 
     /**
      * Returns true of this matrix describes no transformation (is the identity matrix)
      */
     bool isNoTransform()                            const;
 
     MetaEngineRotation& operator*=(const MetaEngineRotation& ma);
 
     /**
      * Applies the given transform to this matrix
      */
     MetaEngineRotation& operator*=(TransformationAction action);
 
     /**
      * Applies the given transform actions to this matrix
      */
     MetaEngineRotation& operator*=(QList<TransformationAction> actions);
 
     /**
      * Applies the given Exif orientation flag to this matrix
      */
     MetaEngineRotation& operator*=(MetaEngine::ImageOrientation exifOrientation);
 
     MetaEngineRotation(int m11, int m12, int m21, int m22);
 
     /**
      * Returns the actions described by this matrix. The order matters.
      * Not all possible matrices are supported, but all those that can be combined
      * by Exif rotation flags and the transform actions above.
      * If isNoTransform() or the matrix is not supported returns an empty list.
      */
     QList<TransformationAction> transformations()   const;
 
     /**
      * Returns the Exif orientation flag describing this matrix.
      * Returns ORIENTATION_UNSPECIFIED if no flag matches this matrix.
      */
     MetaEngine::ImageOrientation exifOrientation()  const;
 
     /**
      * Returns a QTransform representing this matrix
      */
     QTransform toTransform()                              const;
 
     /**
      * Returns a QTransform for the given Exif orientation
      */
     static QTransform toTransform(MetaEngine::ImageOrientation orientation);
 
 protected:
 
     void set(int m11, int m12, int m21, int m22);
 
 protected:
 
     int m[2][2];
 };
 
 } // namespace Digikam
 
 #endif // META_ENGINE_ROTATION_H