PointParticleEmitter2.h

Go to the documentation of this file.

/*************************************************************************
> File Name: PointParticleEmitter2.h
> Project Name: CubbyFlow
> Author: Chan-Ho Chris Ohk
> Purpose: 2-D point particle emitter.
> Created Time: 2017/07/22
> Copyright (c) 2018, Chan-Ho Chris Ohk
*************************************************************************/
#ifndef CUBBYFLOW_POINT_PARTICLE_EMITTER2_H
#define CUBBYFLOW_POINT_PARTICLE_EMITTER2_H

#include <Core/Emitter/ParticleEmitter2.h>

#include <random>

namespace CubbyFlow
{
    class PointParticleEmitter2 final : public ParticleEmitter2
    {
    public:
        class Builder;

        PointParticleEmitter2(
            const Vector2D& origin,
            const Vector2D& direction,
            double speed,
            double spreadAngleInDegrees,
            size_t maxNumOfNewParticlesPerSec = 1,
            size_t maxNumOfParticles = std::numeric_limits<size_t>::max(),
            uint32_t seed = 0);

        size_t GetMaxNumberOfNewParticlesPerSecond() const;

        void SetMaxNumberOfNewParticlesPerSecond(size_t rate);

        size_t GetMaxNumberOfParticles() const;

        void SetMaxNumberOfParticles(size_t maxNumberOfParticles);

        static Builder GetBuilder();

    private:
        std::mt19937 m_rng;

        double m_firstFrameTimeInSeconds = 0.0;
        size_t m_numberOfEmittedParticles = 0;

        size_t m_maxNumberOfNewParticlesPerSecond;
        size_t m_maxNumberOfParticles;

        Vector2D m_origin;
        Vector2D m_direction;
        double m_speed;
        double m_spreadAngleInRadians;

        void OnUpdate(
            double currentTimeInSeconds,
            double timeIntervalInSeconds) override;

        void Emit(
            Array1<Vector2D>* newPositions,
            Array1<Vector2D>* newVelocities,
            size_t maxNewNumberOfParticles);

        double Random();
    };

    using PointParticleEmitter2Ptr = std::shared_ptr<PointParticleEmitter2>;

    class PointParticleEmitter2::Builder final
    {
    public:
        Builder& WithOrigin(const Vector2D& origin);

        Builder& WithDirection(const Vector2D& direction);

        Builder& WithSpeed(double speed);

        Builder& WithSpreadAngleInDegrees(double spreadAngleInDegrees);

        Builder& WithMaxNumberOfNewParticlesPerSecond(size_t maxNumOfNewParticlesPerSec);

        Builder& WithMaxNumberOfParticles(size_t maxNumberOfParticles);

        Builder& WithRandomSeed(uint32_t seed);

        PointParticleEmitter2 Build() const;
        
        PointParticleEmitter2Ptr MakeShared() const;

    private:
        size_t m_maxNumberOfNewParticlesPerSecond = 1;
        size_t m_maxNumberOfParticles = std::numeric_limits<size_t>::max();
        Vector2D m_origin{ 0, 0 };
        Vector2D m_direction{ 0, 1 };
        double m_speed = 1.0;
        double m_spreadAngleInDegrees = 90.0;
        uint32_t m_seed = 0;
    };
}

#endif