source: code/trunk/src/modules/weapons/projectiles/SplitGunProjectile.cc @ 10817

/*
 *   ORXONOX - the hottest 3D action shooter ever to exist
 *                    > www.orxonox.net <
 *
 *
 *   License notice:
 *
 *   This program 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 2
 *   of the License, or (at your option) any later version.
 *
 *   This program 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 this program; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 *   Author:
 *      Fabien Vultier
 *   Co-authors:
 *      ...
 *
 */

/**
    @file SplitGunProjectile.h
    @brief Implementation of the SplitGunProjectile class.
*/

#include "SplitGunProjectile.h"

#include "core/CoreIncludes.h"
#include "core/command/Executor.h"
#include "util/Convert.h"
#include "util/Math.h"

namespace orxonox
{
    RegisterClass(SplitGunProjectile);

    SplitGunProjectile::SplitGunProjectile(Context* context) : BillboardProjectile(context)
    {
        RegisterObject(SplitGunProjectile);

        this->numberOfSplits_ = 0;
        this->numberOfChilds_ = 0;
        this->splitTime_ = 1.0f;
        this->spread_ = 0.2f;
        this->damageReduction_ = 1.0f;
    }

    void SplitGunProjectile::setNumberOfSplits(int numberOfSplits)
    {
        if (numberOfSplits >= 0)
        {
            this->numberOfSplits_ = numberOfSplits;
        }
        else
        {
            this->numberOfSplits_ = 0;
        }
    }

    void SplitGunProjectile::setNumberOfChilds(int numberOfChilds)
    {
        if (numberOfChilds >= 0)
        {
            this->numberOfChilds_ = numberOfChilds;
        }
        else
        {
            this->numberOfChilds_ = 0;
        }
    }

    /**
    @brief
        This function starts a timer that will cause the projectile to split after a time defined by the argument @param splitTime.        
    */
    void SplitGunProjectile::setSplitTime(float splitTime)
    {
        if (splitTime >= 0)
        {
            this->splitTime_ = splitTime;
            this->splitTimer_.setTimer(this->splitTime_, false, createExecutor(createFunctor(&SplitGunProjectile::split, this)));
        }
        else
        {
            this->splitTime_ = 0;
        }
    }

    void SplitGunProjectile::setSpread(float spread)
    {
        this->spread_ = spread;
    }

    /**
    @brief
        This is the setter function for the damageReduction_ variable. The value of the variable is bounded between 0 and 1.
    */
    void SplitGunProjectile::setDamageReduction(float damageReduction)
    {
        this->damageReduction_ = (damageReduction >= 0.0f ? damageReduction : 1.0f);
    }

    /**
    @brief
        If this function is called the projectile splits up into many child projectiles. The original projectiles does not get destroyed but it will never split up again.
    */
    void SplitGunProjectile::split()
    {
        if (numberOfSplits_ > 0)
        {
            -- numberOfSplits_;

            // Reduce damage of this projectile
            this->setDamage(this->getDamage() * this->damageReduction_ / (this->numberOfChilds_+1));

            // Calculate a normalized vector (velocityOffset) that is perpendicluar to the velocity of this projectile. Since there are infinitly many perpendicular vectors a random one is chosen.
            Vector3 velocityInitial = this->getVelocity();
            Vector3 velocityOffset = velocityInitial.perpendicular();
            velocityOffset.normalise();
            Degree angle = Degree(rnd(0,360));
            velocityOffset = Quaternion(angle, velocityInitial.normalisedCopy()) * velocityOffset;
            velocityOffset.normalise();

            // Create as many childs as defined by numberOfChilds_
            for (int i = 0; i < numberOfChilds_; ++i)
            {
                // Every child projectile should fly uniform in different directions -> Rotate the velocityOffset in every iteration
                velocityOffset = Quaternion(Degree(360.0f/numberOfChilds_), velocityInitial.normalisedCopy()) * velocityOffset;
                velocityOffset.normalise();

                SplitGunProjectile* projectile = new SplitGunProjectile(this->getContext());                

                projectile->setMaterial(this->getMaterial());
                projectile->setOrientation(this->getOrientation());
                projectile->setPosition(this->getPosition());
                projectile->setVelocity(velocityInitial + spread_*velocityOffset*velocityInitial.length());

                projectile->setNumberOfSplits(this->numberOfSplits_);
                projectile->setNumberOfChilds(this->numberOfChilds_);
                projectile->setSplitTime(this->splitTime_);
                projectile->setSpread(this->spread_);
                projectile->setDamageReduction(this->damageReduction_);

                projectile->setShooter(this->getShooter());
                projectile->setDamage(this->getDamage());
                projectile->setShieldDamage(this->getShieldDamage());
                projectile->setHealthDamage(this->getHealthDamage());
            }

            numberOfSplits_ = 0;
        }
    }
}