/**
 * *****************************************************************************
 * Copyright (c) 2013, Daniel Murphy
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * 	* Redistributions of source code must retain the above copyright notice,
 * 	  this list of conditions and the following disclaimer.
 * 	* Redistributions in binary form must reproduce the above copyright notice,
 * 	  this list of conditions and the following disclaimer in the documentation
 * 	  and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *****************************************************************************
 */
package org.jbox2d.common;

import java.io.Serializable;

// updated to rev 100
/**
 * A transform contains translation and rotation. It is used to represent the
 * position and orientation of rigid frames.
 */
public class Transform implements Serializable {

    private static final long serialVersionUID = 1L;

    /**
     * The translation caused by the transform
     */
    public final Vec2 p;

    /**
     * A matrix representing a rotation
     */
    public final Rot q;

    /**
     * The default constructor.
     */
    public Transform() {
        p = new Vec2();
        q = new Rot();
    }

    /**
     * Initialize as a copy of another transform.
     *
     * @param xf
     */
    public Transform(final Transform xf) {
        p = xf.p.clone();
        q = xf.q.clone();
    }

    /**
     * Initialize using a position vector and a rotation matrix.
     *
     * @param _position
     * @param _R
     */
    public Transform(final Vec2 _position, final Rot _R) {
        p = _position.clone();
        q = _R.clone();
    }

    /**
     * Set this to equal another transform.
     *
     * @param xf
     * @return
     */
    public final Transform set(final Transform xf) {
        p.set(xf.p);
        q.set(xf.q);
        return this;
    }

    /**
     * Set this based on the position and angle.
     *
     * @param p
     * @param angle
     */
    public final void set(Vec2 p, float angle) {
        this.p.set(p);
        q.set(angle);
    }

    /**
     * Set this to the identity transform.
     */
    public final void setIdentity() {
        p.setZero();
        q.setIdentity();
    }

    public final static Vec2 mul(final Transform T, final Vec2 v) {
        return new Vec2((T.q.c * v.x - T.q.s * v.y) + T.p.x, (T.q.s * v.x + T.q.c * v.y) + T.p.y);
    }

    public final static void mulToOut(final Transform T, final Vec2 v, final Vec2 out) {
        final float tempy = (T.q.s * v.x + T.q.c * v.y) + T.p.y;
        out.x = (T.q.c * v.x - T.q.s * v.y) + T.p.x;
        out.y = tempy;
    }

    public final static void mulToOutUnsafe(final Transform T, final Vec2 v, final Vec2 out) {
        assert (v != out);
        out.x = (T.q.c * v.x - T.q.s * v.y) + T.p.x;
        out.y = (T.q.s * v.x + T.q.c * v.y) + T.p.y;
    }

    public final static Vec2 mulTrans(final Transform T, final Vec2 v) {
        final float px = v.x - T.p.x;
        final float py = v.y - T.p.y;
        return new Vec2((T.q.c * px + T.q.s * py), (-T.q.s * px + T.q.c * py));
    }

    public final static void mulTransToOut(final Transform T, final Vec2 v, final Vec2 out) {
        final float px = v.x - T.p.x;
        final float py = v.y - T.p.y;
        final float tempy = (-T.q.s * px + T.q.c * py);
        out.x = (T.q.c * px + T.q.s * py);
        out.y = tempy;
    }

    public final static void mulTransToOutUnsafe(final Transform T, final Vec2 v, final Vec2 out) {
        assert (v != out);
        final float px = v.x - T.p.x;
        final float py = v.y - T.p.y;
        out.x = (T.q.c * px + T.q.s * py);
        out.y = (-T.q.s * px + T.q.c * py);
    }

    public final static Transform mul(final Transform A, final Transform B) {
        Transform C = new Transform();
        Rot.mulUnsafe(A.q, B.q, C.q);
        Rot.mulToOutUnsafe(A.q, B.p, C.p);
        C.p.addLocal(A.p);
        return C;
    }

    public final static void mulToOut(final Transform A, final Transform B, final Transform out) {
        assert (out != A);
        Rot.mul(A.q, B.q, out.q);
        Rot.mulToOut(A.q, B.p, out.p);
        out.p.addLocal(A.p);
    }

    public final static void mulToOutUnsafe(final Transform A, final Transform B, final Transform out) {
        assert (out != B);
        assert (out != A);
        Rot.mulUnsafe(A.q, B.q, out.q);
        Rot.mulToOutUnsafe(A.q, B.p, out.p);
        out.p.addLocal(A.p);
    }

    private static Vec2 pool = new Vec2();

    public final static Transform mulTrans(final Transform A, final Transform B) {
        Transform C = new Transform();
        Rot.mulTransUnsafe(A.q, B.q, C.q);
        pool.set(B.p).subLocal(A.p);
        Rot.mulTransUnsafe(A.q, pool, C.p);
        return C;
    }

    public final static void mulTransToOut(final Transform A, final Transform B, final Transform out) {
        assert (out != A);
        Rot.mulTrans(A.q, B.q, out.q);
        pool.set(B.p).subLocal(A.p);
        Rot.mulTrans(A.q, pool, out.p);
    }

    public final static void mulTransToOutUnsafe(final Transform A, final Transform B,
            final Transform out) {
        assert (out != A);
        assert (out != B);
        Rot.mulTransUnsafe(A.q, B.q, out.q);
        pool.set(B.p).subLocal(A.p);
        Rot.mulTransUnsafe(A.q, pool, out.p);
    }

    @Override
    public final String toString() {
        String s = "XForm:\n";
        s += "Position: " + p + "\n";
        s += "R: \n" + q + "\n";
        return s;
    }
}