/**
 * @file partsyspacket.cpp
 * @brief Object for packing particle system initialization parameters
 * before sending them over the network.
 *
 * $LicenseInfo:firstyear=2000&license=viewerlgpl$
 * 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
 * $/LicenseInfo$
 */

#include "linden_common.h"

#include "partsyspacket.h"
#include "indra_constants.h"

// this function is global
void gSetInitDataDefaults(LLPartInitData *setMe)
{
    U32 i;

    //for(i = 0; i < 18; i++)
    //{
    //  setMe->k[i] = 0.0f;
    //}

    //setMe->kill_p[0] = setMe->kill_p[1] = setMe->kill_p[2] = 0.0f;
    //setMe->kill_p[3] = -0.2f; // time parameter, die when t= 5.0f
    //setMe->kill_p[4] = 1.0f;
    //setMe->kill_p[5] = -0.5f; // or radius == 2 (contracting)

    //setMe->bounce_p[0] = setMe->bounce_p[1] =
    //  setMe->bounce_p[2] = setMe->bounce_p[3] = 0.0f;
    //setMe->bounce_p[4] = 1.0f;

    setMe->bounce_b = 1.0f;
    // i just changed the meaning of bounce_b
    // its now the attenuation from revlecting your velocity across the normal
    // set by bounce_p

    //setMe->pos_ranges[0] = setMe->pos_ranges[2] = setMe->pos_ranges[4] = -1.0f;
    //setMe->pos_ranges[1] = setMe->pos_ranges[3] = setMe->pos_ranges[5] =  1.0f;

    //setMe->vel_ranges[0] = setMe->vel_ranges[2] = setMe->vel_ranges[4] = -1.0f;
    //setMe->vel_ranges[1] = setMe->vel_ranges[3] = setMe->vel_ranges[5] =  1.0f;

    for(i = 0; i < 3; i++)
    {
        setMe->diffEqAlpha[i] = 0.0f;
        setMe->diffEqScale[i] = 0.0f;
    }

    setMe->scale_range[0] = 1.00f;
    setMe->scale_range[1] = 5.00f;
    setMe->scale_range[2] = setMe->scale_range[3] = 0.0f;

    setMe->alpha_range[0] = setMe->alpha_range[1] = 1.0f;
    setMe->alpha_range[2] = setMe->alpha_range[3] = 0.0f;

    setMe->vel_offset[0] = 0.0f;
    setMe->vel_offset[1] = 0.0f;
    setMe->vel_offset[2] = 0.0f;

    // start dropping particles when I'm more then one sim away
    setMe->mDistBeginFadeout = 256.0f;
    setMe->mDistEndFadeout = 1.414f * 512.0f;
    // stop displaying particles when I'm more then two sim diagonals away

    setMe->mImageUuid = IMG_SHOT;

    for(i = 0; i < 8; i++)
    {
        setMe->mFlags[i] = 0x00;
    }

    setMe->createMe = true;

    setMe->maxParticles = 25;
    setMe->initialParticles = 25;

    //These defaults are for an explosion - a short lived set of debris affected by gravity.
        //Action flags default to PART_SYS_AFFECTED_BY_WIND + PART_SYS_AFFECTED_BY_GRAVITY + PART_SYS_DISTANCE_DEATH
    setMe->mFlags[PART_SYS_ACTION_BYTE] = PART_SYS_AFFECTED_BY_WIND | PART_SYS_AFFECTED_BY_GRAVITY | PART_SYS_DISTANCE_DEATH;
    setMe->mFlags[PART_SYS_KILL_BYTE] = PART_SYS_DISTANCE_DEATH + PART_SYS_TIME_DEATH;

    setMe->killPlaneNormal[0] = 0.0f;setMe->killPlaneNormal[1] = 0.0f;setMe->killPlaneNormal[2] = 1.0f;     //Straight up
    setMe->killPlaneZ = 0.0f;   //get local ground z as an approximation if turn on PART_SYS_KILL_PLANE
    setMe->bouncePlaneNormal[0] = 0.0f;setMe->bouncePlaneNormal[1] = 0.0f;setMe->bouncePlaneNormal[2] = 1.0f;   //Straight up
    setMe->bouncePlaneZ = 0.0f; //get local ground z as an approximation if turn on PART_SYS_BOUNCE
    setMe->spawnRange = 1.0f;
    setMe->spawnFrequency = 0.0f;   //Create the instant one dies
    setMe->spawnFreqencyRange = 0.0f;
    setMe->spawnDirection[0] = 0.0f;setMe->spawnDirection[1] = 0.0f;setMe->spawnDirection[2] = 1.0f;        //Straight up
    setMe->spawnDirectionRange = 1.0f;  //global scattering
    setMe->spawnVelocity = 0.75f;
    setMe->spawnVelocityRange = 0.25f;  //velocity +/- 0.25
    setMe->speedLimit = 1.0f;

    setMe->windWeight = 0.5f;   //0.0f means looks like a heavy object (if gravity is on), 1.0f means light and fluffy
    setMe->currentGravity[0] = 0.0f;setMe->currentGravity[1] = 0.0f;setMe->currentGravity[2] = -9.81f;
        //This has to be constant to allow for compression

    setMe->gravityWeight = 0.5f;    //0.0f means boyed by air, 1.0f means it's a lead weight
    setMe->globalLifetime = 0.0f;   //Arbitrary, but default is no global die, so doesn't matter
    setMe->individualLifetime = 5.0f;
    setMe->individualLifetimeRange = 1.0f;  //Particles last 5 secs +/- 1
    setMe->alphaDecay = 1.0f;   //normal alpha fadeout
    setMe->scaleDecay = 0.0f;   //no scale decay
    setMe->distanceDeath = 10.0f;   //die if hit unit radius
    setMe->dampMotionFactor = 0.0f;

    setMe->windDiffusionFactor[0] = 0.0f;
    setMe->windDiffusionFactor[1] = 0.0f;
    setMe->windDiffusionFactor[2] = 0.0f;
}

LLPartSysCompressedPacket::LLPartSysCompressedPacket()
{
    // default constructor for mDefaults called implicitly/automatically here
    for(int i = 0; i < MAX_PART_SYS_PACKET_SIZE; i++)
    {
        mData[i] = '\0';
    }

    mNumBytes = 0;

    gSetInitDataDefaults(&mDefaults);
}

LLPartSysCompressedPacket::~LLPartSysCompressedPacket()
{
    // no dynamic data is stored by this class, do nothing.
}

void LLPartSysCompressedPacket::writeFlagByte(LLPartInitData *in)
{
        mData[0] =  mData[1] = mData[2] = '\0';

    U32 i;
    //for(i = 1; i < 18; i++) {
    //  if(in->k[i] != mDefaults.k[i])
    //  {
    //      mData[0] |= PART_SYS_K_MASK;
    //      break;
    //  }
    //}

    if(in->killPlaneZ != mDefaults.killPlaneZ ||
        in->killPlaneNormal[0] != mDefaults.killPlaneNormal[0] ||
        in->killPlaneNormal[1] != mDefaults.killPlaneNormal[1] ||
        in->killPlaneNormal[2] != mDefaults.killPlaneNormal[2] ||
        in->distanceDeath != mDefaults.distanceDeath)
    {
        mData[0] |= PART_SYS_KILL_P_MASK;
    }



    if(in->bouncePlaneZ != mDefaults.bouncePlaneZ ||
        in->bouncePlaneNormal[0] != mDefaults.bouncePlaneNormal[0] ||
        in->bouncePlaneNormal[1] != mDefaults.bouncePlaneNormal[1] ||
        in->bouncePlaneNormal[2] != mDefaults.bouncePlaneNormal[2])
    {
        mData[0] |= PART_SYS_BOUNCE_P_MASK;
    }

    if(in->bounce_b != mDefaults.bounce_b)
    {
        mData[0] |= PART_SYS_BOUNCE_B_MASK;
    }


    //if(in->pos_ranges[0] != mDefaults.pos_ranges[0] || in->pos_ranges[1] != mDefaults.pos_ranges[1] ||
    //  in->pos_ranges[2] != mDefaults.pos_ranges[2] || in->pos_ranges[3] != mDefaults.pos_ranges[3] ||
    //  in->pos_ranges[4] != mDefaults.pos_ranges[4] || in->pos_ranges[5] != mDefaults.pos_ranges[5])
    //{
    //  mData[0] |= PART_SYS_POS_RANGES_MASK;
    //}

    //if(in->vel_ranges[0] != mDefaults.vel_ranges[0] || in->vel_ranges[1] != mDefaults.vel_ranges[1] ||
    //  in->vel_ranges[2] != mDefaults.vel_ranges[2] || in->vel_ranges[3] != mDefaults.vel_ranges[3] ||
    //  in->vel_ranges[4] != mDefaults.vel_ranges[4] || in->vel_ranges[5] != mDefaults.vel_ranges[5])
    //{
//      mData[0] |= PART_SYS_VEL_RANGES_MASK;
    //}


    if(in->diffEqAlpha[0] != mDefaults.diffEqAlpha[0] ||
        in->diffEqAlpha[1] != mDefaults.diffEqAlpha[1] ||
        in->diffEqAlpha[2] != mDefaults.diffEqAlpha[2] ||
        in->diffEqScale[0] != mDefaults.diffEqScale[0] ||
        in->diffEqScale[1] != mDefaults.diffEqScale[1] ||
        in->diffEqScale[2] != mDefaults.diffEqScale[2])
    {
        mData[0] |= PART_SYS_ALPHA_SCALE_DIFF_MASK;
    }


    if(in->scale_range[0] != mDefaults.scale_range[0] ||
        in->scale_range[1] != mDefaults.scale_range[1] ||
        in->scale_range[2] != mDefaults.scale_range[2] ||
        in->scale_range[3] != mDefaults.scale_range[3])
    {
        mData[0] |= PART_SYS_SCALE_RANGE_MASK;
    }


    if(in->alpha_range[0] != mDefaults.alpha_range[0] ||
        in->alpha_range[1] != mDefaults.alpha_range[1] ||
        in->alpha_range[2] != mDefaults.alpha_range[2] ||
        in->alpha_range[3] != mDefaults.alpha_range[3])
    {
        mData[2] |= PART_SYS_BYTE_3_ALPHA_MASK;
    }

    if(in->vel_offset[0] != mDefaults.vel_offset[0] ||
        in->vel_offset[1] != mDefaults.vel_offset[1] ||
        in->vel_offset[2] != mDefaults.vel_offset[2])
    {
        mData[0] |= PART_SYS_VEL_OFFSET_MASK;
    }


    if(in->mImageUuid != mDefaults.mImageUuid)
    {
        mData[0] |= PART_SYS_M_IMAGE_UUID_MASK;
    }

    for( i = 0; i < 8; i++)
    {
        if(in->mFlags[i])
        {
            mData[1] |= 1<<i;
//          llprintline("Flag \"%x\" gets byte \"%x\"\n", i<<i, in->mFlags[i]);
        }
    }


    if(in->spawnRange != mDefaults.spawnRange ||
        in->spawnFrequency != mDefaults.spawnFrequency ||
        in->spawnFreqencyRange != mDefaults.spawnFreqencyRange ||
        in->spawnDirection[0] != mDefaults.spawnDirection[0] ||
        in->spawnDirection[1] != mDefaults.spawnDirection[1] ||
        in->spawnDirection[2] != mDefaults.spawnDirection[2] ||
        in->spawnDirectionRange != mDefaults.spawnDirectionRange ||
        in->spawnVelocity != mDefaults.spawnVelocity ||
        in->spawnVelocityRange != mDefaults.spawnVelocityRange)
    {
        mData[3] |= PART_SYS_BYTE_SPAWN_MASK;
    }


    if(in->windWeight != mDefaults.windWeight ||
        in->currentGravity[0] != mDefaults.currentGravity[0] ||
        in->currentGravity[1] != mDefaults.currentGravity[1] ||
        in->currentGravity[2] != mDefaults.currentGravity[2] ||
        in->gravityWeight != mDefaults.gravityWeight)
    {
        mData[3] |= PART_SYS_BYTE_ENVIRONMENT_MASK;
    }


    if(in->globalLifetime != mDefaults.globalLifetime ||
        in->individualLifetime != mDefaults.individualLifetime ||
        in->individualLifetimeRange != mDefaults.individualLifetimeRange)
    {
        mData[3] |= PART_SYS_BYTE_LIFESPAN_MASK;
    }


    if(in->speedLimit != mDefaults.speedLimit ||
        in->alphaDecay != mDefaults.alphaDecay ||
        in->scaleDecay != mDefaults.scaleDecay ||
        in->dampMotionFactor != mDefaults.dampMotionFactor)
    {
        mData[3] |= PART_SYS_BYTE_DECAY_DAMP_MASK;
    }

    if(in->windDiffusionFactor[0] != mDefaults.windDiffusionFactor[0] ||
        in->windDiffusionFactor[1] != mDefaults.windDiffusionFactor[1] ||
        in->windDiffusionFactor[2] != mDefaults.windDiffusionFactor[2])
    {
        mData[3] |= PART_SYS_BYTE_WIND_DIFF_MASK;
    }
}

F32 floatFromTwoBytes(S8 bMant, S8 bExp)
{
    F32 result = bMant;
    while(bExp > 0)
    {
        result *= 2.0f;
        bExp--;
    }
    while(bExp < 0)
    {
        result *= 0.5f;
        bExp++;
    }
    return result;
}

void twoBytesFromFloat(F32 fIn, S8 &bMant, S8 &bExp)
{
    bExp = 0;
    if(fIn > 127.0f)
    {
        fIn = 127.0f;
    }
    if(fIn < -127.0f)
    {
        fIn = -127.0f;
    }
    while(fIn < 64 && fIn > -64 && bExp > -127)
    {
        fIn *= 2.0f;
        bExp--;
    }
    while((fIn > 128 || fIn < -128) && bExp < 127)
    {
        fIn *= 0.5f;
        bExp++;
    }
    bMant = (S8)fIn;
}



/*
U32 LLPartSysCompressedPacket::writeK(LLPartInitData *in, U32 startByte)
{
    U32 i, kFlag, i_mod_eight;
    S8 bMant, bExp;

    kFlag = startByte;

    startByte += 3; // 3 bytes contain enough room for 18 flag bits
    mData[kFlag] = 0x00;
//  llprintline("In the writeK\n");

    i_mod_eight = 0;
    for(i = 0; i < 18; i++)
    {
        if(in->k[i] != mDefaults.k[i])
        {

            mData[kFlag] |= 1<<i_mod_eight;
            twoBytesFromFloat(in->k[i], bMant, bExp);

            mData[startByte++] = bMant;
            mData[startByte++] = bExp;
        }
        i_mod_eight++;
        while(i_mod_eight >= 8)
        {
            kFlag++;
            i_mod_eight -= 8;
        }
    }

    return startByte;
}*/

U32 LLPartSysCompressedPacket::writeKill_p(LLPartInitData *in, U32 startByte)
{
    S8 bMant, bExp;

    twoBytesFromFloat(in->killPlaneNormal[0], bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;
    twoBytesFromFloat(in->killPlaneNormal[1], bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;
    twoBytesFromFloat(in->killPlaneNormal[2], bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;

    twoBytesFromFloat(in->killPlaneZ, bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;
    twoBytesFromFloat(in->distanceDeath, bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;

    return startByte;
}

U32 LLPartSysCompressedPacket::writeBounce_p(LLPartInitData *in, U32 startByte)
{
    S8 bMant, bExp;

    twoBytesFromFloat(in->bouncePlaneNormal[0], bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;
    twoBytesFromFloat(in->bouncePlaneNormal[1], bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;
    twoBytesFromFloat(in->bouncePlaneNormal[2], bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;


    twoBytesFromFloat(in->bouncePlaneZ, bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;

    return startByte;
}

U32 LLPartSysCompressedPacket::writeBounce_b(LLPartInitData *in, U32 startByte)
{
    S8 bMant, bExp;
    twoBytesFromFloat(in->bounce_b, bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;
    return startByte;
}

//U32 LLPartSysCompressedPacket::writePos_ranges(LLPartInitData *in, U32 startByte)
//{
//  S8 tmp;
//  int i;
//  for(i = 0; i < 6; i++)
//  {
//      tmp = (S8) in->pos_ranges[i]; // float to int conversion (keep the sign)
//      mData[startByte++] = (U8)tmp; // signed to unsigned typecast
//  }
//  return startByte;
//}

//U32 LLPartSysCompressedPacket::writeVel_ranges(LLPartInitData *in, U32 startByte)
//{
//  S8 tmp;
//  int i;
//  for(i = 0; i < 6; i++)
//  {
//      tmp = (S8) in->vel_ranges[i]; // float to int conversion (keep the sign)
//      mData[startByte++] = (U8)tmp; // signed to unsigned typecast
//  }
//  return startByte;
//}

U32 LLPartSysCompressedPacket::writeAlphaScaleDiffEqn_range(LLPartInitData *in, U32 startByte)
{
    S8 bExp, bMant;
    int i;
    for(i = 0; i < 3; i++)
    {
        twoBytesFromFloat(in->diffEqAlpha[i], bMant, bExp);
        mData[startByte++] = bMant;
        mData[startByte++] = bExp;
    }
    for(i = 0; i < 3; i++)
    {
        twoBytesFromFloat(in->diffEqScale[i], bMant, bExp);
        mData[startByte++] = bMant;
        mData[startByte++] = bExp;
    }
    return startByte;
}

U32 LLPartSysCompressedPacket::writeScale_range(LLPartInitData *in, U32 startByte)
{
    S8 bExp, bMant;
    int i;
    for(i = 0; i < 4; i++)
    {
        twoBytesFromFloat(in->scale_range[i], bMant, bExp);
        mData[startByte++] = bMant;
        mData[startByte++] = bExp;
    }
    return startByte;
}


U32 LLPartSysCompressedPacket::writeAlpha_range(LLPartInitData *in, U32 startByte)
{
    S8 bExp, bMant;
    int i;
    for(i = 0; i < 4; i++)
    {
        twoBytesFromFloat(in->alpha_range[i], bMant, bExp);
        mData[startByte++] = bMant;
        mData[startByte++] = bExp;
    }
    return startByte;
}

U32 LLPartSysCompressedPacket::writeVelocityOffset(LLPartInitData *in, U32 startByte)
{
    S8 bExp, bMant;
    int i;
    for(i = 0; i < 3; i++)
    {
        twoBytesFromFloat(in->vel_offset[i], bMant, bExp);
        mData[startByte++] = bMant;
        mData[startByte++] = bExp;
    }
    return startByte;
}

U32 LLPartSysCompressedPacket::writeUUID(LLPartInitData *in, U32 startByte)
{
    U8 * bufPtr = mData + startByte;
    if(in->mImageUuid == IMG_SHOT) {
        mData[startByte++] = 0x01;
        return startByte;
    }

    if(in->mImageUuid == IMG_SPARK) {
        mData[startByte++] = 0x02;
        return startByte;
    }


    if(in->mImageUuid == IMG_BIG_EXPLOSION_1) {
        mData[startByte++] = 0x03;
        return startByte;
    }

    if(in->mImageUuid == IMG_BIG_EXPLOSION_2) {
        mData[startByte++] = 0x04;
        return startByte;
    }


    if(in->mImageUuid == IMG_SMOKE_POOF) {
        mData[startByte++] = 0x05;
        return startByte;
    }

    if(in->mImageUuid == IMG_FIRE) {
        mData[startByte++] = 0x06;
        return startByte;
    }


    if(in->mImageUuid == IMG_EXPLOSION) {
        mData[startByte++] = 0x07;
        return startByte;
    }

    if(in->mImageUuid == IMG_EXPLOSION_2) {
        mData[startByte++] = 0x08;
        return startByte;
    }


    if(in->mImageUuid == IMG_EXPLOSION_3) {
        mData[startByte++] = 0x09;
        return startByte;
    }

    if(in->mImageUuid == IMG_EXPLOSION_4) {
        mData[startByte++] = 0x0A;
        return startByte;
    }

    mData[startByte++] = 0x00; // flag for "read whole UUID"

    memcpy(bufPtr, in->mImageUuid.mData, 16);       /* Flawfinder: ignore */
    return (startByte+16);
}

U32 LLPartSysCompressedPacket::writeSpawn(LLPartInitData *in, U32 startByte)
{
    S8 bExp, bMant;
    int i;

    twoBytesFromFloat(in->spawnRange, bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;
    twoBytesFromFloat(in->spawnFrequency, bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;
    twoBytesFromFloat(in->spawnFreqencyRange, bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;



    for(i = 0; i < 3; i++)
    {
        twoBytesFromFloat(in->spawnDirection[i], bMant, bExp);
        mData[startByte++] = bMant;
        mData[startByte++] = bExp;
    }

    twoBytesFromFloat(in->spawnDirectionRange, bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;
    twoBytesFromFloat(in->spawnVelocity, bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;
    twoBytesFromFloat(in->spawnVelocityRange, bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;

    return startByte;
}

U32 LLPartSysCompressedPacket::writeEnvironment(LLPartInitData *in, U32 startByte)
{
    S8 bExp, bMant;
    int i;

    twoBytesFromFloat(in->windWeight, bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;

    for(i = 0; i < 3; i++)
    {
        twoBytesFromFloat(in->currentGravity[i], bMant, bExp);
        mData[startByte++] = bMant;
        mData[startByte++] = bExp;
    }

    twoBytesFromFloat(in->gravityWeight, bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;
    return startByte;
}

U32 LLPartSysCompressedPacket::writeLifespan(LLPartInitData *in, U32 startByte)
{
    S8 bExp, bMant;

    twoBytesFromFloat(in->globalLifetime, bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;

    twoBytesFromFloat(in->individualLifetime, bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;

    twoBytesFromFloat(in->individualLifetimeRange, bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;

    return startByte;
}


U32 LLPartSysCompressedPacket::writeDecayDamp(LLPartInitData *in, U32 startByte)
{
    S8 bExp, bMant;

    twoBytesFromFloat(in->speedLimit, bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;

    twoBytesFromFloat(in->alphaDecay, bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;

    twoBytesFromFloat(in->scaleDecay, bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;

    twoBytesFromFloat(in->dampMotionFactor, bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;

    return startByte;
}

U32 LLPartSysCompressedPacket::writeWindDiffusionFactor(LLPartInitData *in, U32 startByte)
{
    S8 bExp, bMant;

    twoBytesFromFloat(in->windDiffusionFactor[0], bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;

    twoBytesFromFloat(in->windDiffusionFactor[1], bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;

    twoBytesFromFloat(in->windDiffusionFactor[2], bMant, bExp);
    mData[startByte++] = bMant;
    mData[startByte++] = bExp;

    return startByte;
}






/*
U32 LLPartSysCompressedPacket::readK(LLPartInitData *in, U32 startByte)
{
    U32 i, i_mod_eight, kFlag;
    S8 bMant, bExp; // 1 bytes mantissa and exponent for a float
    kFlag = startByte;
    startByte += 3; // 3 bytes has enough room for 18 bits

    i_mod_eight = 0;
    for(i = 0; i < 18; i++)
    {
        if(mData[kFlag]&(1<<i_mod_eight))
        {



            bMant = mData[startByte++];
            bExp = mData[startByte++];


            in->k[i] = floatFromTwoBytes(bMant, bExp); // much tighter platform-independent
            //                                            way to ship floats

        }
        i_mod_eight++;
        if(i_mod_eight >= 8)
        {
            i_mod_eight -= 8;
            kFlag++;
        }
    }

    return startByte;
}
*/

U32 LLPartSysCompressedPacket::readKill_p(LLPartInitData *in, U32 startByte)
{
    S8 bMant, bExp;

    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->killPlaneNormal[0] = floatFromTwoBytes(bMant, bExp);
    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->killPlaneNormal[1] = floatFromTwoBytes(bMant, bExp);
    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->killPlaneNormal[2] = floatFromTwoBytes(bMant, bExp);

    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->killPlaneZ = floatFromTwoBytes(bMant, bExp);
    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->distanceDeath = floatFromTwoBytes(bMant, bExp);

    return startByte;
}

U32 LLPartSysCompressedPacket::readBounce_p(LLPartInitData *in, U32 startByte)
{

    S8 bMant, bExp;

    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->bouncePlaneNormal[0] = floatFromTwoBytes(bMant, bExp);
    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->bouncePlaneNormal[1] = floatFromTwoBytes(bMant, bExp);
    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->bouncePlaneNormal[2] = floatFromTwoBytes(bMant, bExp);

    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->bouncePlaneZ = floatFromTwoBytes(bMant, bExp);

    return startByte;
}

U32 LLPartSysCompressedPacket::readBounce_b(LLPartInitData *in, U32 startByte)
{
    S8 bMant, bExp;
    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->bounce_b = floatFromTwoBytes(bMant, bExp);
    return startByte;
}


//U32 LLPartSysCompressedPacket::readPos_ranges(LLPartInitData *in, U32 startByte)
//{
//  S8 tmp;
//  int i;
//  for(i = 0; i < 6; i++)
//  {
//      tmp = (S8)mData[startByte++];
//      in->pos_ranges[i] = tmp;
//  }
//  return startByte;
//}

//U32 LLPartSysCompressedPacket::readVel_ranges(LLPartInitData *in, U32 startByte)
//{
//  S8 tmp;
//  int i;
//  for(i = 0; i < 6; i++)
//  {
//      tmp = (S8)mData[startByte++];
//      in->vel_ranges[i] = tmp;
//  }
//  return startByte;
//}



U32 LLPartSysCompressedPacket::readAlphaScaleDiffEqn_range(LLPartInitData *in, U32 startByte)
{
    int i;
    S8 bMant, bExp;
    for(i = 0; i < 3; i++)
    {
        bMant = mData[startByte++];
        bExp = mData[startByte++];
        in->diffEqAlpha[i] = floatFromTwoBytes(bMant, bExp);
    }
    for(i = 0; i < 3; i++)
    {
        bMant = mData[startByte++];
        bExp = mData[startByte++];
        in->diffEqScale[i] = floatFromTwoBytes(bMant, bExp);
    }
    return startByte;
}

U32 LLPartSysCompressedPacket::readAlpha_range(LLPartInitData *in, U32 startByte)
{
    int i;
    S8 bMant, bExp;
    for(i = 0; i < 4; i++)
    {
        bMant = mData[startByte++];
        bExp = mData[startByte++];
        in->alpha_range[i] = floatFromTwoBytes(bMant, bExp);
    }
    return startByte;
}

U32 LLPartSysCompressedPacket::readScale_range(LLPartInitData *in, U32 startByte)
{
    int i;
    S8 bMant, bExp;
    for(i = 0; i < 4; i++)
    {
        bMant = mData[startByte++];
        bExp = mData[startByte++];
        in->scale_range[i] = floatFromTwoBytes(bMant, bExp);
    }
    return startByte;
}

U32 LLPartSysCompressedPacket::readVelocityOffset(LLPartInitData *in, U32 startByte)
{
    int i;
    S8 bMant, bExp;
    for(i = 0; i < 3; i++)
    {
        bMant = mData[startByte++];
        bExp = mData[startByte++];
        in->vel_offset[i] = floatFromTwoBytes(bMant, bExp);
    }
    return startByte;
}

U32 LLPartSysCompressedPacket::readUUID(LLPartInitData *in, U32 startByte)
{
    U8 * bufPtr = mData + startByte;

    if(mData[startByte] == 0x01)
    {
        in->mImageUuid = IMG_SHOT;
        return startByte+1;
    }
    if(mData[startByte] == 0x02)
    {
        in->mImageUuid = IMG_SPARK;
        return startByte+1;
    }
    if(mData[startByte] == 0x03)
    {
        in->mImageUuid = IMG_BIG_EXPLOSION_1;
        return startByte+1;
    }
    if(mData[startByte] == 0x04)
    {
        in->mImageUuid = IMG_BIG_EXPLOSION_2;
        return startByte+1;
    }
    if(mData[startByte] == 0x05)
    {
        in->mImageUuid = IMG_SMOKE_POOF;
        return startByte+1;
    }
    if(mData[startByte] == 0x06)
    {
        in->mImageUuid = IMG_FIRE;
        return startByte+1;
    }
    if(mData[startByte] == 0x07)
    {
        in->mImageUuid = IMG_EXPLOSION;
        return startByte+1;
    }
    if(mData[startByte] == 0x08)
    {
        in->mImageUuid = IMG_EXPLOSION_2;
        return startByte+1;
    }
    if(mData[startByte] == 0x09)
    {
        in->mImageUuid = IMG_EXPLOSION_3;
        return startByte+1;
    }
    if(mData[startByte] == 0x0A)
    {
        in->mImageUuid = IMG_EXPLOSION_4;
        return startByte+1;
    }

    startByte++; // cause we actually have to read the UUID now.
    memcpy(in->mImageUuid.mData, bufPtr, 16);       /* Flawfinder: ignore */
    return (startByte+16);
}




U32 LLPartSysCompressedPacket::readSpawn(LLPartInitData *in, U32 startByte)
{
    S8 bMant, bExp;
    U32 i;

    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->spawnRange = floatFromTwoBytes(bMant, bExp);
    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->spawnFrequency = floatFromTwoBytes(bMant, bExp);
    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->spawnFreqencyRange = floatFromTwoBytes(bMant, bExp);

    for(i = 0; i < 3; i++)
    {
        bMant = mData[startByte++];
        bExp = mData[startByte++];
        in->spawnDirection[i] = floatFromTwoBytes(bMant, bExp);
    }

    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->spawnDirectionRange = floatFromTwoBytes(bMant, bExp);
    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->spawnVelocity = floatFromTwoBytes(bMant, bExp);
    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->spawnVelocityRange = floatFromTwoBytes(bMant, bExp);

    return startByte;
}

U32 LLPartSysCompressedPacket::readEnvironment(LLPartInitData *in, U32 startByte)
{
    S8 bMant, bExp;
    U32 i;


    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->windWeight = floatFromTwoBytes(bMant, bExp);

    for(i = 0; i < 3; i++)
    {
        bMant = mData[startByte++];
        bExp = mData[startByte++];
        in->currentGravity[i] = floatFromTwoBytes(bMant, bExp);
    }

    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->gravityWeight = floatFromTwoBytes(bMant, bExp);

    return startByte;
}

U32 LLPartSysCompressedPacket::readLifespan(LLPartInitData *in, U32 startByte)
{
    S8 bMant, bExp;

    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->globalLifetime = floatFromTwoBytes(bMant, bExp);
    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->individualLifetime = floatFromTwoBytes(bMant, bExp);
    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->individualLifetimeRange = floatFromTwoBytes(bMant, bExp);

    return startByte;
}

U32 LLPartSysCompressedPacket::readDecayDamp(LLPartInitData *in, U32 startByte)
{
    S8 bMant, bExp;

    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->speedLimit = floatFromTwoBytes(bMant, bExp);
    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->alphaDecay = floatFromTwoBytes(bMant, bExp);
    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->scaleDecay = floatFromTwoBytes(bMant, bExp);
    bMant = mData[startByte++];
    bExp = mData[startByte++];
    in->dampMotionFactor = floatFromTwoBytes(bMant, bExp);

    return startByte;
}

U32 LLPartSysCompressedPacket::readWindDiffusionFactor(LLPartInitData *in, U32 startByte)
{
    int i;
    S8 bMant, bExp;
    for(i = 0; i < 3; i++)
    {
        bMant = mData[startByte++];
        bExp = mData[startByte++];
        in->windDiffusionFactor[i] = floatFromTwoBytes(bMant, bExp);
    }
    return startByte;
}

bool LLPartSysCompressedPacket::fromLLPartInitData(LLPartInitData *in, U32 &bytesUsed)
{

    writeFlagByte(in);
    U32 currByte = 4;

//  llprintline("calling \"fromLLPartInitData\"\n");

    //if(mData[0] & PART_SYS_K_MASK)
    //{
    //  currByte = writeK(in, 3); // first 3 bytes are reserved for header data
    //}



    if(mData[0] & PART_SYS_KILL_P_MASK)
    {
        currByte = writeKill_p(in, currByte);
    }

    if(mData[0] & PART_SYS_BOUNCE_P_MASK)
    {
        currByte = writeBounce_p(in, currByte);
    }

    if(mData[0] & PART_SYS_BOUNCE_B_MASK)
    {
        currByte = writeBounce_b(in, currByte);
    }

    //if(mData[0] & PART_SYS_POS_RANGES_MASK)
    //{
    //  currByte = writePos_ranges(in, currByte);
    //}

    //if(mData[0] & PART_SYS_VEL_RANGES_MASK)
    //{
    //  currByte = writeVel_ranges(in, currByte);
    //}

    if(mData[0] & PART_SYS_ALPHA_SCALE_DIFF_MASK)
    {
        currByte = writeAlphaScaleDiffEqn_range(in, currByte);
    }

    if(mData[0] & PART_SYS_SCALE_RANGE_MASK)
    {
        currByte = writeScale_range(in, currByte);
    }

    if(mData[0] & PART_SYS_VEL_OFFSET_MASK)
    {
        currByte = writeVelocityOffset(in, currByte);
    }

    if(mData[0] & PART_SYS_M_IMAGE_UUID_MASK)
    {
        currByte = writeUUID(in, currByte);
    }


    if(mData[3] & PART_SYS_BYTE_SPAWN_MASK)
    {
        currByte = writeSpawn(in, currByte);
    }

    if(mData[3] & PART_SYS_BYTE_ENVIRONMENT_MASK)
    {
        currByte = writeEnvironment(in, currByte);
    }

    if(mData[3] & PART_SYS_BYTE_LIFESPAN_MASK)
    {
        currByte = writeLifespan(in, currByte);
    }

    if(mData[3] & PART_SYS_BYTE_DECAY_DAMP_MASK)
    {
        currByte = writeDecayDamp(in, currByte);
    }

    if(mData[3] & PART_SYS_BYTE_WIND_DIFF_MASK)
    {
        currByte = writeWindDiffusionFactor(in, currByte);
    }


    if(mData[2] & PART_SYS_BYTE_3_ALPHA_MASK)
    {
        currByte = writeAlpha_range(in, currByte);
    }

    mData[currByte++] = (U8)in->maxParticles;
    mData[currByte++] = (U8)in->initialParticles;


    U32 flagFlag = 1; // flag indicating which flag bytes are non-zero
    //                   yeah, I know, the name sounds funny
    for(U32 i = 0; i < 8; i++)
    {

//      llprintline("Flag \"%x\" gets byte \"%x\"\n", flagFlag, in->mFlags[i]);
        if(mData[1] & flagFlag)
        {
            mData[currByte++] = in->mFlags[i];
//          llprintline("and is valid...\n");
        }
        flagFlag <<= 1;
    }

    bytesUsed = mNumBytes = currByte;



//  llprintline("returning from \"fromLLPartInitData\" with %d bytes\n", bytesUsed);

    return true;
}

bool LLPartSysCompressedPacket::toLLPartInitData(LLPartInitData *out, U32 *bytesUsed)
{
    U32 currByte = 4;

    gSetInitDataDefaults(out);

    if(mData[0] & PART_SYS_KILL_P_MASK)
    {
        currByte = readKill_p(out, currByte);
    }

    if(mData[0] & PART_SYS_BOUNCE_P_MASK)
    {
        currByte = readBounce_p(out, currByte);
    }

    if(mData[0] & PART_SYS_BOUNCE_B_MASK)
    {
        currByte = readBounce_b(out, currByte);
    }

    if(mData[0] & PART_SYS_ALPHA_SCALE_DIFF_MASK)
    {
        currByte = readAlphaScaleDiffEqn_range(out, currByte);
    }

    if(mData[0] & PART_SYS_SCALE_RANGE_MASK)
    {
        currByte = readScale_range(out, currByte);
    }

    if(mData[0] & PART_SYS_VEL_OFFSET_MASK)
    {
        currByte = readVelocityOffset(out, currByte);
    }

    if(mData[0] & PART_SYS_M_IMAGE_UUID_MASK)
    {
        currByte = readUUID(out, currByte);
    }


    if(mData[3] & PART_SYS_BYTE_SPAWN_MASK)
    {
        currByte = readSpawn(out, currByte);
    }

    if(mData[3] & PART_SYS_BYTE_ENVIRONMENT_MASK)
    {
        currByte = readEnvironment(out, currByte);
    }

    if(mData[3] & PART_SYS_BYTE_LIFESPAN_MASK)
    {
        currByte = readLifespan(out, currByte);
    }

    if(mData[3] & PART_SYS_BYTE_DECAY_DAMP_MASK)
    {
        currByte = readDecayDamp(out, currByte);
    }

    if(mData[3] & PART_SYS_BYTE_WIND_DIFF_MASK)
    {
        currByte = readWindDiffusionFactor(out, currByte);
    }

    if(mData[2] & PART_SYS_BYTE_3_ALPHA_MASK)
    {
        currByte = readAlpha_range(out, currByte);
    }

    out->maxParticles = mData[currByte++];
    out->initialParticles = mData[currByte++];

    U32 flagFlag = 1; // flag indicating which flag bytes are non-zero
    //                   yeah, I know, the name sounds funny
    for(U32 i = 0; i < 8; i++)
    {
        flagFlag = 1<<i;

        if((mData[1] & flagFlag))
        {
            out->mFlags[i] = mData[currByte++];
        }
    }

    *bytesUsed = currByte;
    return true;
}

bool LLPartSysCompressedPacket::fromUnsignedBytes(U8 *in, U32 bytesUsed)
{
    if ((in != NULL) && (bytesUsed <= sizeof(mData)))
    {
        memcpy(mData, in, bytesUsed);   /* Flawfinder: ignore */
        mNumBytes = bytesUsed;
        return true;
    }
    else
    {
        LL_ERRS() << "NULL input data or number of bytes exceed mData size" << LL_ENDL;
        return false;
    }
}


U32 LLPartSysCompressedPacket::bufferSize()
{
    return mNumBytes;
}

bool LLPartSysCompressedPacket::toUnsignedBytes(U8 *out)
{
    memcpy(out, mData, mNumBytes);      /* Flawfinder: ignore */
    return true;
}

U8 * LLPartSysCompressedPacket::getBytePtr()
{
    return mData;
}