KisBicubicFilterStrategy Class Reference

#include <kis_filter_strategy.h>

Inheritance diagram for KisBicubicFilterStrategy:

Public Member Functions
QString	description () override
qint32	intValueAt (qint32 t, qreal weightsPositionScale) const override
	KisBicubicFilterStrategy ()
	~KisBicubicFilterStrategy () override
Public Member Functions inherited from KisFilterStrategy
QString	id ()
virtual qint32	intSupport (qreal weightsPositionScale)
	KisFilterStrategy (KoID id)
QString	name ()
virtual qreal	support (qreal weightsPositionScale)
virtual qreal	valueAt (qreal t, qreal weightsPositionScale) const
virtual	~KisFilterStrategy ()

Additional Inherited Members
Protected Attributes inherited from KisFilterStrategy
qint32	intSupportVal {0}
KoID	m_id
qreal	supportVal {0.0}

Detailed Description

Definition at line 69 of file kis_filter_strategy.h.

Constructor & Destructor Documentation

KisBicubicFilterStrategy()

KisBicubicFilterStrategy::KisBicubicFilterStrategy ( )

inline

Definition at line 72 of file kis_filter_strategy.h.

                               : KisFilterStrategy(KoID("Bicubic", i18n("Bicubic"))) {
        supportVal = 2.0; intSupportVal = 512;
    }

~KisBicubicFilterStrategy()

KisBicubicFilterStrategy::~KisBicubicFilterStrategy ( )

inlineoverride

Definition at line 75 of file kis_filter_strategy.h.

{}

Member Function Documentation

description()

QString KisBicubicFilterStrategy::description ( )

inlineoverridevirtual

Reimplemented from KisFilterStrategy.

Definition at line 77 of file kis_filter_strategy.h.

                                   {
        return i18n("Adds pixels using the color of surrounding pixels. Produces smoother tonal gradations than Bilinear.");
    }

intValueAt()

qint32 KisBicubicFilterStrategy::intValueAt ( qint32 t, qreal weightsPositionScale ) const

overridevirtual

Reimplemented from KisFilterStrategy.

Definition at line 50 of file kis_filter_strategy.cc.

{
    Q_UNUSED(weightsPositionScale);
    /* f(t) = 1.5|t|^3 - 2.5|t|^2 + 1, -1 <= t <= 1 */
    if (t < 0) t = -t;
    if (t < 256) {
        t = (3 * t - 5 * 256) * t * t / 2 + (256 << 16);
 
        //go from .24 fixed point to .8 fixedpoint (hack only works with positive numbers, which it is)
        t = (t + 0x8000) >> 16;
 
        // go from .8 fixed point to 8bitscale. ie t = (t*255)/256;
        if (t >= 128)
            return t - 1;
        return t;
    }
    if (t < 512) {
        /* f(t) = -0.5|t|^3 + 2.5|t|^2 + 4|t| - 2, -2 <= t <= 2 */
        t = ((-t + 5 * 256) * t / 2 - 4 * 256 * 256) * t + (2 * 256 << 16);
 
        //go from .24 fixed point to .8 fixedpoint (hack only works with positive numbers, which it is)
        t = (t + 0x8000) >> 16;
 
        // go from .8 fixed point to 8bitscale. ie t = (t*255)/256;
        if (t >= 128)
            return t - 1;
        return t;
    }
    return(0);
}

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The documentation for this class was generated from the following files:

• libs/image/kis_filter_strategy.h
• libs/image/kis_filter_strategy.cc