/**
 * @file llkeyframefallmotion.cpp
 * @brief Implementation of LLKeyframeFallMotion class.
 *
 * $LicenseInfo:firstyear=2001&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

//-----------------------------------------------------------------------------
// Header Files
//-----------------------------------------------------------------------------
#include "linden_common.h"

#include "llkeyframefallmotion.h"
#include "llcharacter.h"
#include "m3math.h"

//-----------------------------------------------------------------------------
// Macros
//-----------------------------------------------------------------------------
#define GO_TO_KEY_POSE  1
#define MIN_TRACK_SPEED 0.01f

//-----------------------------------------------------------------------------
// LLKeyframeFallMotion()
// Class Constructor
//-----------------------------------------------------------------------------
LLKeyframeFallMotion::LLKeyframeFallMotion(const LLUUID &id) : LLKeyframeMotion(id)
{
    mVelocityZ = 0.f;
    mCharacter = NULL;
}


//-----------------------------------------------------------------------------
// ~LLKeyframeFallMotion()
// Class Destructor
//-----------------------------------------------------------------------------
LLKeyframeFallMotion::~LLKeyframeFallMotion()
{
}


//-----------------------------------------------------------------------------
// LLKeyframeFallMotion::onInitialize()
//-----------------------------------------------------------------------------
LLMotion::LLMotionInitStatus LLKeyframeFallMotion::onInitialize(LLCharacter *character)
{
    // save character pointer for later use
    mCharacter = character;

    // load keyframe data, setup pose and joint states
    LLMotion::LLMotionInitStatus result = LLKeyframeMotion::onInitialize(character);

    if (result != LLMotion::STATUS_SUCCESS)
    {
        return result;
    }

    for (U32 jm=0; jm<mJointMotionList->getNumJointMotions(); jm++)
    {
        if (!mJointStates[jm]->getJoint())
            continue;
        if (mJointStates[jm]->getJoint()->getName() == std::string("mPelvis"))
        {
            mPelvisState = mJointStates[jm];
        }
    }

    return result;
}

//-----------------------------------------------------------------------------
// LLKeyframeFallMotion::onActivate()
//-----------------------------------------------------------------------------
bool LLKeyframeFallMotion::onActivate()
{
    LLVector3 ground_pos;
    LLVector3 ground_normal;
    LLQuaternion inverse_pelvis_rot;
    LLVector3 fwd_axis(1.f, 0.f, 0.f);

    mVelocityZ = -mCharacter->getCharacterVelocity().mV[VZ];
    mCharacter->getGround( mCharacter->getCharacterPosition(), ground_pos, ground_normal);
    ground_normal.normVec();

    inverse_pelvis_rot = mCharacter->getCharacterRotation();
    inverse_pelvis_rot.transQuat();

    // find ground normal in pelvis space
    ground_normal = ground_normal * inverse_pelvis_rot;

    // calculate new foward axis
    fwd_axis = fwd_axis - (ground_normal * (ground_normal * fwd_axis));
    fwd_axis.normVec();
    mRotationToGroundNormal = LLQuaternion(fwd_axis, ground_normal % fwd_axis, ground_normal);

    return LLKeyframeMotion::onActivate();
}

//-----------------------------------------------------------------------------
// LLKeyframeFallMotion::onUpdate()
//-----------------------------------------------------------------------------
bool LLKeyframeFallMotion::onUpdate(F32 activeTime, U8* joint_mask)
{
    LL_PROFILE_ZONE_SCOPED_CATEGORY_AVATAR;
    bool result = LLKeyframeMotion::onUpdate(activeTime, joint_mask);
    F32  slerp_amt = clamp_rescale(activeTime / getDuration(), 0.5f, 0.75f, 0.f, 1.f);

    if (mPelvisState.notNull())
    {
        mPelvisState->setRotation(mPelvisState->getRotation() * slerp(slerp_amt, mRotationToGroundNormal, LLQuaternion()));
    }

    return result;
}

//-----------------------------------------------------------------------------
// LLKeyframeFallMotion::getEaseInDuration()
//-----------------------------------------------------------------------------
F32 LLKeyframeFallMotion::getEaseInDuration()
{
    if (mVelocityZ == 0.f)
    {
        // we've already hit the ground
        return 0.4f;
    }

    return mCharacter->getPreferredPelvisHeight() / mVelocityZ;
}

// End