KisAlgebra2D::DecomposedMatrix Struct Reference

#include <kis_algebra_2d.h>

Public Member Functions
	DecomposedMatrix ()
	DecomposedMatrix (const QTransform &t0)
bool	isValid () const
QTransform	projectTransform () const
QTransform	rotateTransform () const
QTransform	scaleTransform () const
QTransform	shearTransform () const
QTransform	transform () const
QTransform	translateTransform () const

Public Attributes
qreal	angle = 0.0
qreal	dx = 0.0
qreal	dy = 0.0
qreal	proj [3] = {0.0, 0.0, 1.0}
qreal	scaleX = 1.0
qreal	scaleY = 1.0
qreal	shearXY = 0.0

Private Attributes
bool	valid = true

Detailed Description

Definition at line 707 of file kis_algebra_2d.h.

Constructor & Destructor Documentation

DecomposedMatrix() [1/2]

KisAlgebra2D::DecomposedMatrix::DecomposedMatrix

(

)

Definition at line 790 of file kis_algebra_2d.cpp.

{
}

DecomposedMatrix() [2/2]

KisAlgebra2D::DecomposedMatrix::DecomposedMatrix

(

const QTransform &

t0

)

Definition at line 794 of file kis_algebra_2d.cpp.

{
    QTransform t(t0);
 
    QTransform projMatrix;
 
    if (t.m33() == 0.0 || t0.determinant() == 0.0) {
        qWarning() << "Cannot decompose matrix!" << t;
        valid = false;
        return;
    }
 
    if (t.type() == QTransform::TxProject) {
        QTransform affineTransform(
            t.m11(), t.m12(), 0,
            t.m21(), t.m22(), 0,
            t.m31(), t.m32(), 1
        );
        projMatrix = affineTransform.inverted() * t;
 
        t = affineTransform;
        proj[0] = projMatrix.m13();
        proj[1] = projMatrix.m23();
        proj[2] = projMatrix.m33();
    }
 
    // can't use QVector3D, because they have too little accuracy for ellipse in perspective calculations
    std::array<Eigen::Vector3d, 3> rows;
 
 
    //  << t.m11() << t.m12() << t.m13())
    rows[0] = Eigen::Vector3d(t.m11(), t.m12(), t.m13());
    rows[1] = Eigen::Vector3d(t.m21(), t.m22(), t.m23());
    rows[2] = Eigen::Vector3d(t.m31(), t.m32(), t.m33());
 
    if (!qFuzzyCompare(t.m33(), 1.0)) {
        const qreal invM33 = 1.0 / t.m33();
 
        for (auto &row : rows) {
            row *= invM33;
        }
    }
 
    dx = rows[2].x();
    dy = rows[2].y();
 
    rows[2] = Eigen::Vector3d(0,0,1);
 
 
    scaleX = rows[0].norm();
    rows[0] *= 1.0 / scaleX;
 
    shearXY = rows[0].dot(rows[1]);
    rows[1] = rows[1] - shearXY * rows[0];
 
    scaleY = rows[1].norm();
    rows[1] *= 1.0 / scaleY;
    shearXY *= 1.0 / scaleY;
 
    // If determinant is negative, one axis was flipped.
    qreal determinant = rows[0].x() * rows[1].y() - rows[0].y() * rows[1].x();
    if (determinant < 0) {
        // Flip axis with minimum unit vector dot product.
        if (rows[0].x() < rows[1].y()) {
            scaleX = -scaleX;
            rows[0] = -rows[0];
        } else {
            scaleY = -scaleY;
            rows[1] = -rows[1];
        }
        shearXY = - shearXY;
    }
 
    angle = kisRadiansToDegrees(std::atan2(rows[0].y(), rows[0].x()));
 
    if (angle != 0.0) {
        // Rotate(-angle) = [cos(angle), sin(angle), -sin(angle), cos(angle)]
        //                = [row0x, -row0y, row0y, row0x]
        // Thanks to the normalization above.
 
        qreal sn = -rows[0].y();
        qreal cs = rows[0].x();
        qreal m11 = rows[0].x();
        qreal m12 = rows[0].y();
        qreal m21 = rows[1].x();
        qreal m22 = rows[1].y();
        rows[0][0] = (cs * m11 + sn * m21);
        rows[0][1] = (cs * m12 + sn * m22);
        rows[1][0] = (-sn * m11 + cs * m21);
        rows[1][1] = (-sn * m12 + cs * m22);
    }
 
    QTransform leftOver(
                rows[0].x(), rows[0].y(), rows[0].z(),
            rows[1].x(), rows[1].y(), rows[1].z(),
            rows[2].x(), rows[2].y(), rows[2].z());
 
    if (/*true || */!fuzzyMatrixCompare(leftOver, QTransform(), 1e-4)) {
        // what's wrong?
        ENTER_FUNCTION() << "FAILING THE ASSERT BELOW!";
        ENTER_FUNCTION() << ppVar(leftOver);
        ENTER_FUNCTION() << "matrix to decompose was: " << ppVar(t0);
        ENTER_FUNCTION() << ppVar(t.m33()) << ppVar(t0.determinant());
        Eigen::Matrix3d mat1 = fromQTransformStraight(QTransform());
        Eigen::Matrix3d mat2 = fromQTransformStraight(leftOver);
        Eigen::Matrix3d mat3 = mat2 - mat1;
        ENTER_FUNCTION() << mat3(0, 0) << mat3(0, 1) << mat3(0, 2);
        ENTER_FUNCTION() << mat3(1, 0) << mat3(1, 1) << mat3(1, 2);
        ENTER_FUNCTION() << mat3(2, 0) << mat3(2, 1) << mat3(2, 2);
        //ENTER_FUNCTION() << ppVar(mat1 - mat2);
    }
 
 
    KIS_SAFE_ASSERT_RECOVER_NOOP(fuzzyMatrixCompare(leftOver, QTransform(), 1e-4));
    KIS_ASSERT(fuzzyMatrixCompare(leftOver, QTransform(), 1e-4));
}

References angle, dx, dy, ENTER_FUNCTION, KisAlgebra2D::fromQTransformStraight(), KisAlgebra2D::fuzzyMatrixCompare(), KIS_ASSERT, KIS_SAFE_ASSERT_RECOVER_NOOP, kisRadiansToDegrees(), ppVar, proj, qFuzzyCompare(), scaleX, scaleY, shearXY, and valid.

Member Function Documentation

isValid()

bool KisAlgebra2D::DecomposedMatrix::isValid ( ) const

inline

Definition at line 754 of file kis_algebra_2d.h.

                                {
        return valid;
    }

projectTransform()

QTransform KisAlgebra2D::DecomposedMatrix::projectTransform ( ) const

inline

Definition at line 736 of file kis_algebra_2d.h.

    {
        return
            QTransform(
                1,0,proj[0],
                0,1,proj[1],
                0,0,proj[2]);
    }

rotateTransform()

QTransform KisAlgebra2D::DecomposedMatrix::rotateTransform ( ) const

inline

Definition at line 724 of file kis_algebra_2d.h.

    {
        QTransform t;
        t.rotate(angle);
        return t;
    }

scaleTransform()

QTransform KisAlgebra2D::DecomposedMatrix::scaleTransform ( ) const

inline

Definition at line 712 of file kis_algebra_2d.h.

    {
        return QTransform::fromScale(scaleX, scaleY);
    }

shearTransform()

QTransform KisAlgebra2D::DecomposedMatrix::shearTransform ( ) const

inline

Definition at line 717 of file kis_algebra_2d.h.

    {
        QTransform t;
        t.shear(shearXY, 0);
        return t;
    }

transform()

QTransform KisAlgebra2D::DecomposedMatrix::transform ( ) const

inline

Definition at line 745 of file kis_algebra_2d.h.

                                        {
        return
            scaleTransform() *
            shearTransform() *
            rotateTransform() *
            translateTransform() *
            projectTransform();
    }

translateTransform()

QTransform KisAlgebra2D::DecomposedMatrix::translateTransform ( ) const

inline

Definition at line 731 of file kis_algebra_2d.h.

    {
        return QTransform::fromTranslate(dx, dy);
    }

Member Data Documentation

angle

qreal KisAlgebra2D::DecomposedMatrix::angle = 0.0

Definition at line 761 of file kis_algebra_2d.h.

dx

qreal KisAlgebra2D::DecomposedMatrix::dx = 0.0

Definition at line 762 of file kis_algebra_2d.h.

dy

qreal KisAlgebra2D::DecomposedMatrix::dy = 0.0

Definition at line 763 of file kis_algebra_2d.h.

proj

qreal KisAlgebra2D::DecomposedMatrix::proj[3] = {0.0, 0.0, 1.0}

Definition at line 764 of file kis_algebra_2d.h.

{0.0, 0.0, 1.0};

scaleX

qreal KisAlgebra2D::DecomposedMatrix::scaleX = 1.0

Definition at line 758 of file kis_algebra_2d.h.

scaleY

qreal KisAlgebra2D::DecomposedMatrix::scaleY = 1.0

Definition at line 759 of file kis_algebra_2d.h.

shearXY

qreal KisAlgebra2D::DecomposedMatrix::shearXY = 0.0

Definition at line 760 of file kis_algebra_2d.h.

valid

bool KisAlgebra2D::DecomposedMatrix::valid = true

private

Definition at line 767 of file kis_algebra_2d.h.

---

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

• libs/global/kis_algebra_2d.h
• libs/global/kis_algebra_2d.cpp