llkeyframemotion.cpp

/** 
 * @file llkeyframemotion.cpp
 * @brief Implementation of LLKeyframeMotion 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 "llmath.h"
#include "llanimationstates.h"
#include "llassetstorage.h"
#include "lldatapacker.h"
#include "llcharacter.h"
#include "llcriticaldamp.h"
#include "lldir.h"
#include "llendianswizzle.h"
#include "llkeyframemotion.h"
#include "llquantize.h"
#include "m3math.h"
#include "message.h"
#include "llfilesystem.h"

//-----------------------------------------------------------------------------
// Static Definitions
//-----------------------------------------------------------------------------
LLKeyframeDataCache::keyframe_data_map_t	LLKeyframeDataCache::sKeyframeDataMap;

//-----------------------------------------------------------------------------
// Globals
//-----------------------------------------------------------------------------
static F32 JOINT_LENGTH_K = 0.7f;
static S32 MAX_ITERATIONS = 20;
static S32 MIN_ITERATIONS = 1;
static S32 MIN_ITERATION_COUNT = 2;
static F32 MAX_PIXEL_AREA_CONSTRAINTS = 80000.f;
static F32 MIN_PIXEL_AREA_CONSTRAINTS = 1000.f;
static F32 MIN_ACCELERATION_SQUARED = 0.0005f * 0.0005f;

static F32 MAX_CONSTRAINTS = 10;

//-----------------------------------------------------------------------------
// JointMotionList
//-----------------------------------------------------------------------------
LLKeyframeMotion::JointMotionList::JointMotionList()
	: mDuration(0.f),
	  mLoop(FALSE),
	  mLoopInPoint(0.f),
	  mLoopOutPoint(0.f),
	  mEaseInDuration(0.f),
	  mEaseOutDuration(0.f),
	  mBasePriority(LLJoint::LOW_PRIORITY),
	  mHandPose(LLHandMotion::HAND_POSE_SPREAD),
	  mMaxPriority(LLJoint::LOW_PRIORITY)
{
}

LLKeyframeMotion::JointMotionList::~JointMotionList()
{
	for_each(mConstraints.begin(), mConstraints.end(), DeletePointer());
	mConstraints.clear();
	for_each(mJointMotionArray.begin(), mJointMotionArray.end(), DeletePointer());
	mJointMotionArray.clear();
}

U32 LLKeyframeMotion::JointMotionList::dumpDiagInfo()
{
	S32	total_size = sizeof(JointMotionList);

	for (U32 i = 0; i < getNumJointMotions(); i++)
	{
		LLKeyframeMotion::JointMotion* joint_motion_p = mJointMotionArray[i];

		LL_INFOS() << "\tJoint " << joint_motion_p->mJointName << LL_ENDL;
		if (joint_motion_p->mUsage & LLJointState::SCALE)
		{
			LL_INFOS() << "\t" << joint_motion_p->mScaleCurve.mNumKeys << " scale keys at " 
			<< joint_motion_p->mScaleCurve.mNumKeys * sizeof(ScaleKey) << " bytes" << LL_ENDL;

			total_size += joint_motion_p->mScaleCurve.mNumKeys * sizeof(ScaleKey);
		}
		if (joint_motion_p->mUsage & LLJointState::ROT)
		{
			LL_INFOS() << "\t" << joint_motion_p->mRotationCurve.mNumKeys << " rotation keys at " 
			<< joint_motion_p->mRotationCurve.mNumKeys * sizeof(RotationKey) << " bytes" << LL_ENDL;

			total_size += joint_motion_p->mRotationCurve.mNumKeys * sizeof(RotationKey);
		}
		if (joint_motion_p->mUsage & LLJointState::POS)
		{
			LL_INFOS() << "\t" << joint_motion_p->mPositionCurve.mNumKeys << " position keys at " 
			<< joint_motion_p->mPositionCurve.mNumKeys * sizeof(PositionKey) << " bytes" << LL_ENDL;

			total_size += joint_motion_p->mPositionCurve.mNumKeys * sizeof(PositionKey);
		}
	}
	LL_INFOS() << "Size: " << total_size << " bytes" << LL_ENDL;

	return total_size;
}

//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
// JointMotion class
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------

//-----------------------------------------------------------------------------
// JointMotion::update()
//-----------------------------------------------------------------------------
void LLKeyframeMotion::JointMotion::update(LLJointState* joint_state, F32 time, F32 duration)
{
	// this value being 0 is the cause of https://jira.lindenlab.com/browse/SL-22678 but I haven't 
	// managed to get a stack to see how it got here. Testing for 0 here will stop the crash.
	if ( joint_state == NULL )
	{
		return;
	}

	U32 usage = joint_state->getUsage();

	//-------------------------------------------------------------------------
	// update scale component of joint state
	//-------------------------------------------------------------------------
	if ((usage & LLJointState::SCALE) && mScaleCurve.mNumKeys)
	{
		joint_state->setScale( mScaleCurve.getValue( time, duration ) );
	}

	//-------------------------------------------------------------------------
	// update rotation component of joint state
	//-------------------------------------------------------------------------
	if ((usage & LLJointState::ROT) && mRotationCurve.mNumKeys)
	{
		joint_state->setRotation( mRotationCurve.getValue( time, duration ) );
	}

	//-------------------------------------------------------------------------
	// update position component of joint state
	//-------------------------------------------------------------------------
	if ((usage & LLJointState::POS) && mPositionCurve.mNumKeys)
	{
		joint_state->setPosition( mPositionCurve.getValue( time, duration ) );
	}
}


//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
// LLKeyframeMotion class
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------

//-----------------------------------------------------------------------------
// LLKeyframeMotion()
// Class Constructor
//-----------------------------------------------------------------------------
LLKeyframeMotion::LLKeyframeMotion(const LLUUID &id) 
	: LLMotion(id),
		mJointMotionList(NULL),
		mPelvisp(NULL),
		mCharacter(NULL),
		mLastSkeletonSerialNum(0),
		mLastUpdateTime(0.f),
		mLastLoopedTime(0.f),
		mAssetStatus(ASSET_UNDEFINED)
{

}


//-----------------------------------------------------------------------------
// ~LLKeyframeMotion()
// Class Destructor
//-----------------------------------------------------------------------------
LLKeyframeMotion::~LLKeyframeMotion()
{
	for_each(mConstraints.begin(), mConstraints.end(), DeletePointer());
	mConstraints.clear();
}

//-----------------------------------------------------------------------------
// create()
//-----------------------------------------------------------------------------
LLMotion *LLKeyframeMotion::create(const LLUUID &id)
{
	return new LLKeyframeMotion(id);
}

//-----------------------------------------------------------------------------
// getJointState()
//-----------------------------------------------------------------------------
LLPointer<LLJointState>& LLKeyframeMotion::getJointState(U32 index)
{
	llassert_always (index < mJointStates.size());
	return mJointStates[index];
}

//-----------------------------------------------------------------------------
// getJoint()
//-----------------------------------------------------------------------------
LLJoint* LLKeyframeMotion::getJoint(U32 index)
{
	llassert_always (index < mJointStates.size());
	LLJoint* joint = mJointStates[index]->getJoint();
	
	//Commented out 06-28-11 by Aura.
	//llassert_always (joint);
	return joint;
}

//-----------------------------------------------------------------------------
// LLKeyframeMotion::onInitialize(LLCharacter *character)
//-----------------------------------------------------------------------------
LLMotion::LLMotionInitStatus LLKeyframeMotion::onInitialize(LLCharacter *character)
{
	mCharacter = character;
	
	LLUUID* character_id;

	// asset already loaded?
	switch(mAssetStatus)
	{
	case ASSET_NEEDS_FETCH:
		// request asset
		mAssetStatus = ASSET_FETCHED;

#ifdef SHOW_DEBUG
        LL_DEBUGS("Animation") << "Requesting data fetch for: " << mID << LL_ENDL;
#endif
		character_id = new LLUUID(mCharacter->getID());
		gAssetStorage->getAssetData(mID,
						LLAssetType::AT_ANIMATION,
						onLoadComplete,
						(void *)character_id,
						FALSE);

		return STATUS_HOLD;
	case ASSET_FETCHED:
		return STATUS_HOLD;
	case ASSET_FETCH_FAILED:
		return STATUS_FAILURE;
	case ASSET_LOADED:
		return STATUS_SUCCESS;
	default:
		// we don't know what state the asset is in yet, so keep going
		// check keyframe cache first then file cache then asset request
		break;
	}

	LLKeyframeMotion::JointMotionList* joint_motion_list = LLKeyframeDataCache::getKeyframeData(getID());

	if(joint_motion_list)
	{
		// motion already existed in cache, so grab it
		mJointMotionList = joint_motion_list;

		mJointStates.reserve(mJointMotionList->getNumJointMotions());
		
		// don't forget to allocate joint states
		// set up joint states to point to character joints
		for(U32 i = 0; i < mJointMotionList->getNumJointMotions(); i++)
		{
			JointMotion* joint_motion = mJointMotionList->getJointMotion(i);
			if (LLJoint *joint = mCharacter->getJoint(joint_motion->mJointName))
			{
				LLPointer<LLJointState> joint_state = new LLJointState;
				mJointStates.push_back(joint_state);
				joint_state->setJoint(joint);
				joint_state->setUsage(joint_motion->mUsage);
				joint_state->setPriority(joint_motion->mPriority);
			}
			else
			{
				// add dummy joint state with no associated joint
				mJointStates.push_back(new LLJointState);
			}
		}
		mAssetStatus = ASSET_LOADED;
		setupPose();
		return STATUS_SUCCESS;
	}

	//-------------------------------------------------------------------------
	// Load named file by concatenating the character prefix with the motion name.
	// Load data into a buffer to be parsed.
	//-------------------------------------------------------------------------
	BOOL success = FALSE;
	U8* anim_data = nullptr;
	S32 anim_file_size = 0;

	{
		LLFileSystem anim_file(mID, LLAssetType::AT_ANIMATION);
		if (!anim_file.open() || !anim_file.getSize())
		{
			// request asset over network on next call to load
			mAssetStatus = ASSET_NEEDS_FETCH;

			return STATUS_HOLD;
		}
		else
		{
			anim_file_size = anim_file.getSize();
			anim_data = new(std::nothrow) U8[anim_file_size];
			if (anim_data)
			{
				success = anim_file.read(anim_data, anim_file_size);
				if (!success)
				{
					delete[] anim_data;
					anim_data = nullptr;
					LL_WARNS() << "Failed to read animation from cache. ID: " << mID << LL_ENDL;
				}
			}
			else
			{
				LL_WARNS() << "Failed to allocate buffer: " << anim_file_size << " " << mID << LL_ENDL;
			}
		}
	}

	if (!success)
	{
		LL_WARNS() << "Can't open animation file " << mID << LL_ENDL;
		mAssetStatus = ASSET_FETCH_FAILED;
		return STATUS_FAILURE;
	}

#ifdef SHOW_DEBUG
	LL_DEBUGS() << "Loading keyframe data for: " << getName() << ":" << getID() << " (" << anim_file_size << " bytes)" << LL_ENDL;
#endif

	LLDataPackerBinaryBuffer dp(anim_data, anim_file_size);

	if (!deserialize(dp, getID()))
	{
		LL_WARNS() << "Failed to decode asset for animation " << getName() << ":" << getID() << LL_ENDL;
		mAssetStatus = ASSET_FETCH_FAILED;
		return STATUS_FAILURE;
	}

	delete []anim_data;

	mAssetStatus = ASSET_LOADED;
	return STATUS_SUCCESS;
}

//-----------------------------------------------------------------------------
// setupPose()
//-----------------------------------------------------------------------------
BOOL LLKeyframeMotion::setupPose()
{
	// add all valid joint states to the pose
	for (U32 jm=0; jm<mJointMotionList->getNumJointMotions(); jm++)
	{
		LLPointer<LLJointState> joint_state = getJointState(jm);
		if ( joint_state->getJoint() )
		{
			addJointState( joint_state );
		}
	}

	// initialize joint constraints
	for (JointMotionList::constraint_list_t::iterator iter = mJointMotionList->mConstraints.begin();
		 iter != mJointMotionList->mConstraints.end(); ++iter)
	{
		JointConstraintSharedData* shared_constraintp = *iter;
		JointConstraint* constraintp = new JointConstraint(shared_constraintp);
		initializeConstraint(constraintp);
		mConstraints.push_front(constraintp);
	}

	if (mJointMotionList->mConstraints.size())
	{
		mPelvisp = mCharacter->getJoint("mPelvis");
		if (!mPelvisp)
		{
			return FALSE;
		}
	}

	// setup loop keys
	setLoopIn(mJointMotionList->mLoopInPoint);
	setLoopOut(mJointMotionList->mLoopOutPoint);

	return TRUE;
}

//-----------------------------------------------------------------------------
// LLKeyframeMotion::onActivate()
//-----------------------------------------------------------------------------
BOOL LLKeyframeMotion::onActivate()
{
	// If the keyframe anim has an associated emote, trigger it. 
	if( mJointMotionList->mEmoteName.length() > 0 )
	{
		LLUUID emote_anim_id = gAnimLibrary.stringToAnimState(mJointMotionList->mEmoteName);
		// don't start emote if already active to avoid recursion
		if (!mCharacter->isMotionActive(emote_anim_id))
		{
			mCharacter->startMotion( emote_anim_id );
		}
	}

	mLastLoopedTime = 0.f;

	return TRUE;
}

//-----------------------------------------------------------------------------
// LLKeyframeMotion::onUpdate()
//-----------------------------------------------------------------------------
BOOL LLKeyframeMotion::onUpdate(F32 time, U8* joint_mask)
{
	// llassert(time >= 0.f);		// This will fire
	time = llmax(0.f, time);

	if (mJointMotionList->mLoop)
	{
		if (mJointMotionList->mDuration == 0.0f)
		{
			time = 0.f;
			mLastLoopedTime = 0.0f;
		}
		else if (mStopped)
		{
			mLastLoopedTime = llmin(mJointMotionList->mDuration, mLastLoopedTime + time - mLastUpdateTime);
		}
		else if (time > mJointMotionList->mLoopOutPoint)
		{
			if ((mJointMotionList->mLoopOutPoint - mJointMotionList->mLoopInPoint) == 0.f)
			{
				mLastLoopedTime = mJointMotionList->mLoopOutPoint;
			}
			else
			{
				mLastLoopedTime = mJointMotionList->mLoopInPoint + 
					fmod(time - mJointMotionList->mLoopOutPoint, 
					mJointMotionList->mLoopOutPoint - mJointMotionList->mLoopInPoint);
			}
		}
		else
		{
			mLastLoopedTime = time;
		}
	}
	else
	{
		mLastLoopedTime = time;
	}

	applyKeyframes(mLastLoopedTime);

	applyConstraints(mLastLoopedTime, joint_mask);

	mLastUpdateTime = time;

	return mLastLoopedTime <= mJointMotionList->mDuration;
}

//-----------------------------------------------------------------------------
// applyKeyframes()
//-----------------------------------------------------------------------------
void LLKeyframeMotion::applyKeyframes(F32 time)
{
	llassert_always (mJointMotionList->getNumJointMotions() <= mJointStates.size());
	for (U32 i=0; i<mJointMotionList->getNumJointMotions(); i++)
	{
		mJointMotionList->getJointMotion(i)->update(mJointStates[i],
													  time, 
													  mJointMotionList->mDuration );
	}

	LLJoint::JointPriority* pose_priority = (LLJoint::JointPriority* )mCharacter->getAnimationData("Hand Pose Priority");
	if (pose_priority)
	{
		if (mJointMotionList->mMaxPriority >= *pose_priority)
		{
			mCharacter->setAnimationData("Hand Pose", &mJointMotionList->mHandPose);
			mCharacter->setAnimationData("Hand Pose Priority", &mJointMotionList->mMaxPriority);
		}
	}
	else
	{
		mCharacter->setAnimationData("Hand Pose", &mJointMotionList->mHandPose);
		mCharacter->setAnimationData("Hand Pose Priority", &mJointMotionList->mMaxPriority);
	}
}

//-----------------------------------------------------------------------------
// applyConstraints()
//-----------------------------------------------------------------------------
void LLKeyframeMotion::applyConstraints(F32 time, U8* joint_mask)
{
	//TODO: investigate replacing spring simulation with critically damped motion

	// re-init constraints if skeleton has changed
	if (mCharacter->getSkeletonSerialNum() != mLastSkeletonSerialNum)
	{
		mLastSkeletonSerialNum = mCharacter->getSkeletonSerialNum();
		for (constraint_list_t::iterator iter = mConstraints.begin();
			 iter != mConstraints.end(); ++iter)
		{
			JointConstraint* constraintp = *iter;
			initializeConstraint(constraintp);
		}
	}

	// apply constraints
	for (constraint_list_t::iterator iter = mConstraints.begin();
		 iter != mConstraints.end(); ++iter)
	{
		JointConstraint* constraintp = *iter;
		applyConstraint(constraintp, time, joint_mask);
	}
}

//-----------------------------------------------------------------------------
// LLKeyframeMotion::onDeactivate()
//-----------------------------------------------------------------------------
void LLKeyframeMotion::onDeactivate()
{
	for (constraint_list_t::iterator iter = mConstraints.begin();
		 iter != mConstraints.end(); ++iter)
	{
		JointConstraint* constraintp = *iter;
		deactivateConstraint(constraintp);
	}
}

//-----------------------------------------------------------------------------
// setStopTime()
//-----------------------------------------------------------------------------
// time is in seconds since character creation
void LLKeyframeMotion::setStopTime(F32 time)
{
	LLMotion::setStopTime(time);

	if (mJointMotionList->mLoop && mJointMotionList->mLoopOutPoint != mJointMotionList->mDuration)
	{
		F32 start_loop_time = mActivationTimestamp + mJointMotionList->mLoopInPoint;
		F32 loop_fraction_time;
		if (mJointMotionList->mLoopOutPoint == mJointMotionList->mLoopInPoint)
		{
			loop_fraction_time = 0.f;
		}
		else
		{
			loop_fraction_time = fmod(time - start_loop_time, 
				mJointMotionList->mLoopOutPoint - mJointMotionList->mLoopInPoint);
		}
		mStopTimestamp = llmax(time, 
			(time - loop_fraction_time) + (mJointMotionList->mDuration - mJointMotionList->mLoopInPoint) - getEaseOutDuration());
	}
}

//-----------------------------------------------------------------------------
// initializeConstraint()
//-----------------------------------------------------------------------------
void LLKeyframeMotion::initializeConstraint(JointConstraint* constraint)
{
	JointConstraintSharedData *shared_data = constraint->mSharedData;

	S32 joint_num;
	LLVector3 source_pos = mCharacter->getVolumePos(shared_data->mSourceConstraintVolume, shared_data->mSourceConstraintOffset);
	LLJoint* cur_joint = getJoint(shared_data->mJointStateIndices[0]);
	if ( !cur_joint )
	{
		return;
	}
	
	F32 source_pos_offset = dist_vec(source_pos, cur_joint->getWorldPosition());

	constraint->mTotalLength = constraint->mJointLengths[0] = dist_vec(cur_joint->getParent()->getWorldPosition(), source_pos);
	
	// grab joint lengths
	for (joint_num = 1; joint_num < shared_data->mChainLength; joint_num++)
	{
		cur_joint = getJointState(shared_data->mJointStateIndices[joint_num])->getJoint();
		if (!cur_joint)
		{
			return;
		}
		constraint->mJointLengths[joint_num] = dist_vec(cur_joint->getWorldPosition(), cur_joint->getParent()->getWorldPosition());
		constraint->mTotalLength += constraint->mJointLengths[joint_num];
	}

	// store fraction of total chain length so we know how to shear the entire chain towards the goal position
	for (joint_num = 1; joint_num < shared_data->mChainLength; joint_num++)
	{
		constraint->mJointLengthFractions[joint_num] = constraint->mJointLengths[joint_num] / constraint->mTotalLength;
	}

	// add last step in chain, from final joint to constraint position
	constraint->mTotalLength += source_pos_offset;

	constraint->mSourceVolume = mCharacter->findCollisionVolume(shared_data->mSourceConstraintVolume);
	constraint->mTargetVolume = mCharacter->findCollisionVolume(shared_data->mTargetConstraintVolume);
}

//-----------------------------------------------------------------------------
// activateConstraint()
//-----------------------------------------------------------------------------
void LLKeyframeMotion::activateConstraint(JointConstraint* constraint)
{
	JointConstraintSharedData *shared_data = constraint->mSharedData;
	constraint->mActive = TRUE;
	S32 joint_num;

	// grab ground position if we need to
	if (shared_data->mConstraintTargetType == CONSTRAINT_TARGET_TYPE_GROUND)
	{
		LLVector3 source_pos = mCharacter->getVolumePos(shared_data->mSourceConstraintVolume, shared_data->mSourceConstraintOffset);
		LLVector3 ground_pos_agent;
		mCharacter->getGround(source_pos, ground_pos_agent, constraint->mGroundNorm);
		constraint->mGroundPos = mCharacter->getPosGlobalFromAgent(ground_pos_agent + shared_data->mTargetConstraintOffset);
	}

	for (joint_num = 1; joint_num < shared_data->mChainLength; joint_num++)
	{
		LLJoint* cur_joint = getJoint(shared_data->mJointStateIndices[joint_num]);
		if ( !cur_joint )
		{
			return;
		}
		constraint->mPositions[joint_num] = (cur_joint->getWorldPosition() - mPelvisp->getWorldPosition()) * ~mPelvisp->getWorldRotation();
	}

	constraint->mWeight = 1.f;
}

//-----------------------------------------------------------------------------
// deactivateConstraint()
//-----------------------------------------------------------------------------
void LLKeyframeMotion::deactivateConstraint(JointConstraint *constraintp)
{
	if (constraintp->mSourceVolume)
	{
		constraintp->mSourceVolume->mUpdateXform = FALSE;
	}

	if (constraintp->mSharedData->mConstraintTargetType != CONSTRAINT_TARGET_TYPE_GROUND)
	{
		if (constraintp->mTargetVolume)
		{
			constraintp->mTargetVolume->mUpdateXform = FALSE;
		}
	}
	constraintp->mActive = FALSE;
}

//-----------------------------------------------------------------------------
// applyConstraint()
//-----------------------------------------------------------------------------
void LLKeyframeMotion::applyConstraint(JointConstraint* constraint, F32 time, U8* joint_mask)
{
	JointConstraintSharedData *shared_data = constraint->mSharedData;
	if (!shared_data) return;

	LLVector3		positions[MAX_CHAIN_LENGTH];
	const F32*		joint_lengths = constraint->mJointLengths;
	LLVector3		velocities[MAX_CHAIN_LENGTH - 1];
	LLQuaternion	old_rots[MAX_CHAIN_LENGTH];
	S32				joint_num;

	if (time < shared_data->mEaseInStartTime)
	{
		return;
	}

	if (time > shared_data->mEaseOutStopTime)
	{
		if (constraint->mActive)
		{
			deactivateConstraint(constraint);
		}
		return;
	}

	if (!constraint->mActive || time < shared_data->mEaseInStopTime)
	{
		activateConstraint(constraint);
	}

	LLJoint* root_joint = getJoint(shared_data->mJointStateIndices[shared_data->mChainLength]);
	if (! root_joint) 
	{
		return;
	}
	
	LLVector3 root_pos = root_joint->getWorldPosition();
//	LLQuaternion root_rot = 
	root_joint->getParent()->getWorldRotation();
//	LLQuaternion inv_root_rot = ~root_rot;

//	LLVector3 current_source_pos = mCharacter->getVolumePos(shared_data->mSourceConstraintVolume, shared_data->mSourceConstraintOffset);

	//apply underlying keyframe animation to get nominal "kinematic" joint positions
	for (joint_num = 0; joint_num <= shared_data->mChainLength; joint_num++)
	{
		LLJoint* cur_joint = getJoint(shared_data->mJointStateIndices[joint_num]);
		if (!cur_joint)
		{
			return;
		}
		
		if (joint_mask[cur_joint->getJointNum()] >= (0xff >> (7 - getPriority())))
		{
			// skip constraint
			return;
		}
		old_rots[joint_num] = cur_joint->getRotation();
		cur_joint->setRotation(getJointState(shared_data->mJointStateIndices[joint_num])->getRotation());
	}


	LLVector3 keyframe_source_pos = mCharacter->getVolumePos(shared_data->mSourceConstraintVolume, shared_data->mSourceConstraintOffset);
	LLVector3 target_pos;

	switch(shared_data->mConstraintTargetType)
	{
	case CONSTRAINT_TARGET_TYPE_GROUND:
		target_pos = mCharacter->getPosAgentFromGlobal(constraint->mGroundPos);
//		LL_INFOS() << "Target Pos " << constraint->mGroundPos << " on " << mCharacter->findCollisionVolume(shared_data->mSourceConstraintVolume)->getName() << LL_ENDL;
		break;
	case CONSTRAINT_TARGET_TYPE_BODY:
		target_pos = mCharacter->getVolumePos(shared_data->mTargetConstraintVolume, shared_data->mTargetConstraintOffset);
		break;
	default:
		break;
	}
	
	LLVector3 norm;
	LLJoint *source_jointp = NULL;
	LLJoint *target_jointp = NULL;

	if (shared_data->mConstraintType == CONSTRAINT_TYPE_PLANE)
	{
		switch(shared_data->mConstraintTargetType)
		{
		case CONSTRAINT_TARGET_TYPE_GROUND:
			norm = constraint->mGroundNorm;
			break;
		case CONSTRAINT_TARGET_TYPE_BODY:
			target_jointp = mCharacter->findCollisionVolume(shared_data->mTargetConstraintVolume);
			if (target_jointp)
			{
				// *FIX: do proper normal calculation for stretched
				// spheres (inverse transpose)
				norm = target_pos - target_jointp->getWorldPosition();
			}

			if (norm.isExactlyZero())
			{
				source_jointp = mCharacter->findCollisionVolume(shared_data->mSourceConstraintVolume);
				norm = -1.f * shared_data->mSourceConstraintOffset;
				if (source_jointp)	
				{
					norm = norm * source_jointp->getWorldRotation();
				}
			}
			norm.normVec();
			break;
		default:
			norm.clearVec();
			break;
		}
		
		target_pos = keyframe_source_pos + (norm * ((target_pos - keyframe_source_pos) * norm));
	}

	if (constraint->mSharedData->mChainLength != 0 &&
		dist_vec_squared(root_pos, target_pos) * 0.95f > constraint->mTotalLength * constraint->mTotalLength)
	{
		constraint->mWeight = LLSmoothInterpolation::lerp(constraint->mWeight, 0.f, 0.1f);
	}
	else
	{
		constraint->mWeight = LLSmoothInterpolation::lerp(constraint->mWeight, 1.f, 0.3f);
	}

	F32 weight = constraint->mWeight * ((shared_data->mEaseOutStopTime == 0.f) ? 1.f : 
		llmin(clamp_rescale(time, shared_data->mEaseInStartTime, shared_data->mEaseInStopTime, 0.f, 1.f), 
		clamp_rescale(time, shared_data->mEaseOutStartTime, shared_data->mEaseOutStopTime, 1.f, 0.f)));

	LLVector3 source_to_target = target_pos - keyframe_source_pos;
	
	S32 max_iteration_count = ll_round(clamp_rescale(
										  mCharacter->getPixelArea(),
										  MAX_PIXEL_AREA_CONSTRAINTS,
										  MIN_PIXEL_AREA_CONSTRAINTS,
										  (F32)MAX_ITERATIONS,
										  (F32)MIN_ITERATIONS));

	if (shared_data->mChainLength)
	{
		LLJoint* end_joint = getJoint(shared_data->mJointStateIndices[0]);
		
		if (!end_joint)
		{
			return;
		}
		
		LLQuaternion end_rot = end_joint->getWorldRotation();

		// slam start and end of chain to the proper positions (rest of chain stays put)
		positions[0] = lerp(keyframe_source_pos, target_pos, weight);
		positions[shared_data->mChainLength] = root_pos;

		// grab keyframe-specified positions of joints	
		for (joint_num = 1; joint_num < shared_data->mChainLength; joint_num++)
		{
			LLJoint* cur_joint = getJoint(shared_data->mJointStateIndices[joint_num]);
			
			if (!cur_joint)
			{
				return;
			}
			
			LLVector3 kinematic_position = cur_joint->getWorldPosition() + 
				(source_to_target * constraint->mJointLengthFractions[joint_num]);

			// convert intermediate joint positions to world coordinates
			positions[joint_num] = ( constraint->mPositions[joint_num] * mPelvisp->getWorldRotation()) + mPelvisp->getWorldPosition();
			F32 time_constant = 1.f / clamp_rescale(constraint->mFixupDistanceRMS, 0.f, 0.5f, 0.2f, 8.f);
//			LL_INFOS() << "Interpolant " << LLSmoothInterpolation::getInterpolant(time_constant, FALSE) << " and fixup distance " << constraint->mFixupDistanceRMS << " on " << mCharacter->findCollisionVolume(shared_data->mSourceConstraintVolume)->getName() << LL_ENDL;
			positions[joint_num] = lerp(positions[joint_num], kinematic_position, 
				LLSmoothInterpolation::getInterpolant(time_constant, FALSE));
		}

		S32 iteration_count;
		for (iteration_count = 0; iteration_count < max_iteration_count; iteration_count++)
		{
			S32 num_joints_finished = 0;
			for (joint_num = 1; joint_num < shared_data->mChainLength; joint_num++)
			{
				// constraint to child
				LLVector3 acceleration = (positions[joint_num - 1] - positions[joint_num]) * 
					(dist_vec(positions[joint_num], positions[joint_num - 1]) - joint_lengths[joint_num - 1]) * JOINT_LENGTH_K;
				// constraint to parent
				acceleration  += (positions[joint_num + 1] - positions[joint_num]) * 
					(dist_vec(positions[joint_num + 1], positions[joint_num]) - joint_lengths[joint_num]) * JOINT_LENGTH_K;

				if (acceleration.magVecSquared() < MIN_ACCELERATION_SQUARED)
				{
					num_joints_finished++;
				}

				velocities[joint_num - 1] = velocities[joint_num - 1] * 0.7f;
				positions[joint_num] += velocities[joint_num - 1] + (acceleration * 0.5f);
				velocities[joint_num - 1] += acceleration;
			}

			if ((iteration_count >= MIN_ITERATION_COUNT) && 
				(num_joints_finished == shared_data->mChainLength - 1))
			{
//				LL_INFOS() << iteration_count << " iterations on " << 
//					mCharacter->findCollisionVolume(shared_data->mSourceConstraintVolume)->getName() << LL_ENDL;
				break;
			}
		}

		for (joint_num = shared_data->mChainLength; joint_num > 0; joint_num--)
		{
			LLJoint* cur_joint = getJoint(shared_data->mJointStateIndices[joint_num]);
			
			if (!cur_joint)
			{
				return;
			}
			LLJoint* child_joint = getJoint(shared_data->mJointStateIndices[joint_num - 1]);
			if (!child_joint)
			{
				return;
			}
			
			LLQuaternion parent_rot = cur_joint->getParent()->getWorldRotation();

			LLQuaternion cur_rot = cur_joint->getWorldRotation();
			LLQuaternion fixup_rot;
			
			LLVector3 target_at = positions[joint_num - 1] - positions[joint_num];
			LLVector3 current_at;

			// at bottom of chain, use point on collision volume, not joint position
			if (joint_num == 1)
			{
				current_at = mCharacter->getVolumePos(shared_data->mSourceConstraintVolume, shared_data->mSourceConstraintOffset) -
					cur_joint->getWorldPosition();
			}
			else
			{
				current_at = child_joint->getPosition() * cur_rot;
			}
			fixup_rot.shortestArc(current_at, target_at);

			LLQuaternion target_rot = cur_rot * fixup_rot;
			target_rot = target_rot * ~parent_rot;

			if (weight != 1.f)
			{
				LLQuaternion cur_rot = getJointState(shared_data->mJointStateIndices[joint_num])->getRotation();
				target_rot = nlerp(weight, cur_rot, target_rot);
			}

			getJointState(shared_data->mJointStateIndices[joint_num])->setRotation(target_rot);
			cur_joint->setRotation(target_rot);
		}

		LLQuaternion end_local_rot = end_rot * ~end_joint->getParent()->getWorldRotation();

		if (weight == 1.f)
		{
			getJointState(shared_data->mJointStateIndices[0])->setRotation(end_local_rot);
		}
		else
		{
			LLQuaternion cur_rot = getJointState(shared_data->mJointStateIndices[0])->getRotation();
			getJointState(shared_data->mJointStateIndices[0])->setRotation(nlerp(weight, cur_rot, end_local_rot));
		}

		// save simulated positions in pelvis-space and calculate total fixup distance
		constraint->mFixupDistanceRMS = 0.f;
		F32 delta_time = llmax(0.02f, llabs(time - mLastUpdateTime));
		for (joint_num = 1; joint_num < shared_data->mChainLength; joint_num++)
		{
			LLVector3 new_pos = (positions[joint_num] - mPelvisp->getWorldPosition()) * ~mPelvisp->getWorldRotation();
			constraint->mFixupDistanceRMS += dist_vec_squared(new_pos, constraint->mPositions[joint_num]) / delta_time;
			constraint->mPositions[joint_num] = new_pos;
		}
		constraint->mFixupDistanceRMS *= 1.f / (constraint->mTotalLength * (F32)(shared_data->mChainLength - 1));
		constraint->mFixupDistanceRMS = (F32) sqrt(constraint->mFixupDistanceRMS);

		//reset old joint rots
		for (joint_num = 0; joint_num <= shared_data->mChainLength; joint_num++)
		{
			LLJoint* cur_joint = getJoint(shared_data->mJointStateIndices[joint_num]);
			if (!cur_joint)
			{
				return;
			}

			cur_joint->setRotation(old_rots[joint_num]);
		}
	}
	// simple positional constraint (pelvis only)
	else if (getJointState(shared_data->mJointStateIndices[0])->getUsage() & LLJointState::POS)
	{
		LLVector3 delta = source_to_target * weight;
		LLPointer<LLJointState> current_joint_state = getJointState(shared_data->mJointStateIndices[0]);
		LLQuaternion parent_rot = current_joint_state->getJoint()->getParent()->getWorldRotation();
		delta = delta * ~parent_rot;
		current_joint_state->setPosition(current_joint_state->getJoint()->getPosition() + delta);
	}
}

//-----------------------------------------------------------------------------
// deserialize()
//-----------------------------------------------------------------------------
BOOL LLKeyframeMotion::deserialize(LLDataPacker& dp, const LLUUID& asset_id)
{
	BOOL old_version = FALSE;
    auto joint_motion_list = std::make_unique<LLKeyframeMotion::JointMotionList>();

	//-------------------------------------------------------------------------
	// get base priority
	//-------------------------------------------------------------------------
	S32 temp_priority;
	U16 version;
	U16 sub_version;

	if (!dp.unpackU16(version, "version"))
	{
		LL_WARNS() << "can't read version number for animation " << asset_id << LL_ENDL;
		return FALSE;
	}

	if (!dp.unpackU16(sub_version, "sub_version"))