/*---------------------------------------------------------------------------*
  Project:  Horizon
  File:     demo_Particle.cpp

  Copyright (C)2009-2012 Nintendo Co., Ltd.  All rights reserved.

  These coded instructions, statements, and computer programs contain
  proprietary information of Nintendo of America Inc. and/or Nintendo
  Company Ltd., and are protected by Federal copyright law.  They may
  not be disclosed to third parties or copied or duplicated in any form,
  in whole or in part, without the prior written consent of Nintendo.

  $Rev: 46365 $
 *---------------------------------------------------------------------------*/

#include "demo/Body/demo_Particle.h"

namespace demo
{
    /* ------------------------------------------------------------------------
        Particle class  member function
        ------------------------------------------------------------------------ */

    bool Particle::s_Initialize = false;

    u32 Particle::s_InitialLifeTime = 30;
    f32 Particle::s_InitialMass = 1.0f;
    nn::math::Vector3 Particle::s_InitialPosition(0.0f, 0.0f, 0.0f);
    nn::math::Vector3 Particle::s_InitialVelocity(0.0f, 0.0f, 0.0f);
    nn::math::Vector3 Particle::s_RandomVelocityScale(1.0f, 0.0f, 1.0f);
    nn::math::Vector3 Particle::s_Gravity(0.0f, 0.0f, 0.0f);       
    f32 Particle::s_InitialRadius = 0.4f;

    Particle::Particle(void) :
    m_LifeTime(0.0f),
    m_Mass(s_InitialMass),
    m_Position(s_InitialPosition), m_Velocity(s_InitialVelocity),
    m_Acceleration(s_Gravity),
    m_Color(1.0f, 0.0f, 0.0f),
    m_Sphere()
    {   
        if ( ! s_Initialize  )
        {
            ::std::srand(0x1234);

            s_Initialize = true;
        }
    }

    Particle::~Particle()
    {
    }

    void Particle::Initialize(void)
    {
        u32 vertexAttributes = demo::VERTEX_POSITION_ATTRIBUTE | 
            demo::VERTEX_COLOR_ATTRIBUTE | 
            demo::VERTEX_NORMAL_ATTRIBUTE |         
            demo::VERTEX_TEXCOORD_ATTRIBUTE;
        InitializeParticle(vertexAttributes, s_InitialRadius, 2);
    }

    void Particle::InitializeParticle(const u32 vertexAttributes, 
        const f32 radius, const u32 division)
    {
        m_Sphere.InitializeSphere(vertexAttributes, radius, division);
   
        f32 red = static_cast<f32>(::std::rand() % 256) / 256.0f;
        f32 green = static_cast<f32>(::std::rand() % 256) / 256.0f;
        f32 blue = static_cast<f32>(::std::rand() % 256) / 256.0f;      
        m_Sphere.SetColor(red, green, blue);

        m_Acceleration = s_Gravity;

        Spawn();
    }

    void Particle::Finalize(void)
    {
        m_Sphere.Finalize();
    }

    void Particle::Update(const f32 time)
    {
        m_LifeTime -= time;
        if ( m_LifeTime < 0 )
        {        
            Spawn();        
        }
        else
        {
            for (u32 index = 0; index < 3; index++)
            {
                nn::math::Vector3 deltaVec;
                nn::math::VEC3Scale(&deltaVec, &m_Acceleration, time / m_Mass);
                m_Velocity += deltaVec;
                nn::math::VEC3Scale(&deltaVec, &m_Velocity, time);
                m_Position += deltaVec;
            }   
            m_Sphere.SetWorldPosition(m_Position.x, m_Position.y, m_Position.z);
        }
    }

    void Particle::Spawn(void)
    {
        m_LifeTime = static_cast<f32>(::std::rand() % s_InitialLifeTime);
       
        m_Position = s_InitialPosition;
        m_Velocity.x = s_RandomVelocityScale.x * (static_cast<f32>(::std::rand() % 256) / 256.0f - 0.5f) + s_InitialVelocity.x;
        m_Velocity.y = s_RandomVelocityScale.y * (static_cast<f32>(::std::rand() % 256) / 256.0f - 0.5f) + s_InitialVelocity.y;
        m_Velocity.z = s_RandomVelocityScale.z * (static_cast<f32>(::std::rand() % 256) / 256.0f - 0.5f) + s_InitialVelocity.z;
    }

    nn::math::MTX44 Particle::GetWorldMatrix(void) const
    {
        return m_Sphere.GetWorldMatrix();
    }

    void Particle::Draw(void)
    {
        m_Sphere.Draw();
    }

}