/* This file is part of HSPlasma.
 *
 * HSPlasma is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HSPlasma is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HSPlasma.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef _HSAFFINEPARTS_H
#define _HSAFFINEPARTS_H

#include "hsGeometry3.h"
#include "hsQuat.h"

/**
 * \brief Defines an Affine transformation.
 *
 * This class is used to store the components of an Affine transformation,
 * mostly for use in animations and other movement.
 */

class PLASMA_DLL hsAffineParts {
public:
    /**
     * The meaning of this field is currently unknown...  It might be an
     * unused flag set, or an unused component of Affine transformations.
     * Either way, it was removed in MOUL, and seems to always be 0
     * in the other engines (at least as far as I've seen).
     */
    int fI;

    /** Defines the Translation component */
    hsVector3 fT;

    /** Defines the Rotation component */
    hsQuat fQ;

    /** Defines the axis system of the Scaling component */
    hsQuat fU;

    /** Defines the Scaling component */
    hsVector3 fK;

    /** Either 1.0 or -1.0; defines the sign of the determinant */
    float fF;

public:
    /** Constructs a default (identity) Affine Transformation */
    hsAffineParts() : fI(0), fK(1.0f, 1.0f, 1.0f), fF(1.0f) { }

    /** Read the affine parts from a versioned stream */
    void read(hsStream* S);

    /** Write the affine parts to a versioned stream */
    void write(hsStream* S);

    /** Write an Affine Transformation tag to the PRC document */
    void prcWrite(pfPrcHelper* prc);

    /** Parse an Affine Transformation tag into the current object */
    void prcParse(const pfPrcTag* tag);

    /** Reset the Affine Transformation to its identity form */
    void reset();
};

#endif
