Collidoscope

/*

 Copyright (C) 2015  Fiore Martin

 Copyright (C) 2016  Queen Mary University of London

 Author: Fiore Martin

 This file is part of Collidoscope.

 Collidoscope 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 3 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, see <http://www.gnu.org/licenses/>.

*/

#pragma once

#include "cinder/gl/gl.h"

#include <vector>

/**

 * The ParticleController creates/updates/draws and destroys particles

 */

class ParticleController {

    struct Particle {

        ci::vec2        mCloudCenter; // initial positin of the particle

        ci::vec2        mVel;         // velocity

        float       mCloudSize;   // how big is the area where particle float around. When a particle hits the

                                  //   border of the area it gets deflected

        int                        mAge;      // when mAge == mLifeSpan the particle is disposed

        int                        mLifespan; // how long a particle lives

        bool        mFlyOver;  // some particles last longer and fly over the screen and reach the other user

    };

    static const int kMaxParticles = 150;

        std::vector<Particle> mParticles;

    std::vector< ci::vec2 > mParticlePositions;

    // current number of active particles

    size_t mNumParticles;

    ci::gl::VboRef                        mParticleVbo;    // virtual buffer object

    ci::gl::BatchRef                mParticleBatch;

 public:

    /**

     * Every time addParticles is run, up to kMaxParticleAdd are added at once

     */

    static const int kMaxParticleAdd = 22;

    ParticleController();

    /**

     * Adds \a amount particles and places them in \a initialLocation.

     * \cloudSize determines how far the particles can go

     */

        void addParticles(int amount, const ci::vec2 &initialLocation, const float cloudSize);

    /**

     * Updates position and age of the particles

     */

    void updateParticles();

    /**

     * Draws all the particles

     */

    inline void draw()

    {

        mParticleBatch->draw();

    }

};