File indexing completed on 2024-05-12 15:58:15

 /*
  *  SPDX-FileCopyrightText: 2004 Michael Thaler <michael.thaler@physik.tu-muenchen.de>
  *  SPDX-FileCopyrightText: 2005 C. Boemann <cbo@boemann.dk>
  *  SPDX-FileCopyrightText: 2013 Juan Palacios <jpalaciosdev@gmail.com>
  *
  *  SPDX-License-Identifier: GPL-2.0-or-later
  */
 
 #ifndef KIS_FILTER_STRATEGY_H_
 #define KIS_FILTER_STRATEGY_H_
 
 #include <klocalizedstring.h>
 
 #include "KoGenericRegistry.h"
 #include "KoID.h"
 #include "kritaimage_export.h"
 #include <QSize>
 
 class KRITAIMAGE_EXPORT KisFilterStrategy
 {
 public:
     KisFilterStrategy(KoID id) : m_id(id) {}
     virtual ~KisFilterStrategy() {  }
 
     QString id() {
         return m_id.id();
     }
     QString name() {
         return m_id.name();
     }
     virtual qreal valueAt(qreal t, qreal weightsPositionScale) const {
         Q_UNUSED(t);
         Q_UNUSED(weightsPositionScale);
         return 0;
     }
     virtual qint32 intValueAt(qint32 t, qreal weightsPositionScale) const {
         return qint32(255*valueAt(t / 256.0, weightsPositionScale));
     }
     virtual qreal support(qreal weightsPositionScale) {
         Q_UNUSED(weightsPositionScale);
         return supportVal;
     }
     virtual qint32 intSupport(qreal weightsPositionScale) {
         Q_UNUSED(weightsPositionScale);
         return intSupportVal;
     }
     virtual QString description() {
         return QString();
     }
 
 protected:
     qreal supportVal {0.0};
     qint32 intSupportVal {0};
     KoID m_id;
 };
 
 class KRITAIMAGE_EXPORT KisHermiteFilterStrategy : public KisFilterStrategy
 {
 public:
     KisHermiteFilterStrategy() : KisFilterStrategy(KoID("Hermite", i18n("Hermite"))) {
         supportVal = 1.0; intSupportVal = 256;
     }
     ~KisHermiteFilterStrategy() override {}
 
     qint32 intValueAt(qint32 t, qreal weightsPositionScale) const override;
     qreal valueAt(qreal t, qreal weightsPositionScale) const override;
 };
 
 class KRITAIMAGE_EXPORT KisBicubicFilterStrategy : public KisFilterStrategy
 {
 public:
     KisBicubicFilterStrategy() : KisFilterStrategy(KoID("Bicubic", i18n("Bicubic"))) {
         supportVal = 2.0; intSupportVal = 512;
     }
     ~KisBicubicFilterStrategy() override {}
 
     QString description() override {
         return i18n("Adds pixels using the color of surrounding pixels. Produces smoother tonal gradations than Bilinear.");
     }
 
     qint32 intValueAt(qint32 t, qreal weightsPositionScale) const override;
 };
 class KRITAIMAGE_EXPORT KisBoxFilterStrategy : public KisFilterStrategy
 {
 public:
     KisBoxFilterStrategy() : KisFilterStrategy(KoID("NearestNeighbor", i18n("Nearest Neighbor"))) {
         // 0.5 and 128, but with a bit of margin to ensure the correct pixel will be used
         // even in case of calculation errors
         supportVal = 0.51; intSupportVal = 129;
     }
     ~KisBoxFilterStrategy() override {}
 
     QString description() override {
         return i18n("Replicate pixels in the image. Preserves all the original detail, but can produce jagged effects.");
     }
 
     virtual qreal support(qreal weightsPositionScale) override;
     virtual qint32 intSupport(qreal weightsPositionScale) override;
 
 
     qint32 intValueAt(qint32 t, qreal weightsPositionScale) const override;
     qreal valueAt(qreal t, qreal weightsPositionScale) const override;
 };
 
 class KRITAIMAGE_EXPORT KisBilinearFilterStrategy : public KisFilterStrategy
 {
 public:
     KisBilinearFilterStrategy() : KisFilterStrategy(KoID("Bilinear", i18n("Bilinear"))) {
         supportVal = 1.0; intSupportVal = 256;
     }
     ~KisBilinearFilterStrategy() override {}
 
     QString description() override {
         return i18n("Adds pixels averaging the color values of surrounding pixels. Produces medium quality results when the image is scaled from half to two times the original size.");
     }
 
     qint32 intValueAt(qint32 t, qreal weightsPositionScale) const override;
     qreal valueAt(qreal t, qreal weightsPositionScale) const override;
 };
 
 class KRITAIMAGE_EXPORT KisBellFilterStrategy : public KisFilterStrategy
 {
 public:
     KisBellFilterStrategy() : KisFilterStrategy(KoID("Bell", i18n("Bell"))) {
         supportVal = 1.5; intSupportVal = 128 + 256;
     }
     ~KisBellFilterStrategy() override {}
 
     qreal valueAt(qreal t, qreal weightsPositionScale) const override;
 };
 
 class KRITAIMAGE_EXPORT KisBSplineFilterStrategy : public KisFilterStrategy
 {
 public:
     KisBSplineFilterStrategy() : KisFilterStrategy(KoID("BSpline", i18n("BSpline"))) {
         supportVal = 2.0; intSupportVal = 512;
     }
     ~KisBSplineFilterStrategy() override {}
 
     qreal valueAt(qreal t, qreal weightsPositionScale) const override;
 };
 
 class KRITAIMAGE_EXPORT KisLanczos3FilterStrategy : public KisFilterStrategy
 {
 public:
     KisLanczos3FilterStrategy() : KisFilterStrategy(KoID("Lanczos3", i18n("Lanczos3"))) {
         supportVal = 3.0; intSupportVal = 768;
     }
     ~KisLanczos3FilterStrategy() override {}
 
     QString description() override {
         return i18n("Offers similar results than Bicubic, but maybe a little bit sharper. Can produce light and dark halos along strong edges.");
     }
 
     qreal valueAt(qreal t, qreal weightsPositionScale) const override;
 private:
     qreal sinc(qreal x) const;
 };
 
 class KRITAIMAGE_EXPORT  KisMitchellFilterStrategy : public KisFilterStrategy
 {
 public:
     KisMitchellFilterStrategy() : KisFilterStrategy(KoID("Mitchell", i18n("Mitchell"))) {
         supportVal = 2.0; intSupportVal = 256;
     }
     ~KisMitchellFilterStrategy() override {}
 
     qreal valueAt(qreal t, qreal weightsPositionScale) const override;
 };
 
 class KRITAIMAGE_EXPORT KisFilterStrategyRegistry : public KoGenericRegistry<KisFilterStrategy *>
 {
 
 public:
 
     KisFilterStrategyRegistry();
     ~KisFilterStrategyRegistry() override;
     static KisFilterStrategyRegistry* instance();
 
     /**
      * This function return a list of all the keys in KoID format by using the name() method
      * on the objects stored in the registry.
      */
     QList<KoID> listKeys() const;
 
     /**
      * This function return a string formatted in HTML that contains the descriptions of all objects
      * (with a non empty description) stored in the registry.
      */
     QString formattedDescriptions() const;
 
     /**
      * Try to select an appropriate image filtering strategy based on original and desired parameters.
      */
     KisFilterStrategy* autoFilterStrategy(QSize originalSize, QSize desiredSize) const;
 
 private:
 
     KisFilterStrategyRegistry(const KisFilterStrategyRegistry&);
     KisFilterStrategyRegistry operator=(const KisFilterStrategyRegistry&);
 
 };
 
 #endif // KIS_FILTER_STRATEGY_H_