//
//  InitialModule.cpp
//  libcocos2d Mac
//
//  Created by 徐俊杰 on 2020/4/24.
//

#include "rparticle/Modules/InitialModule.h"

//#include "UnityPrefix.h"
//#include "Runtime/BaseClasses/ObjectDefines.h"
#include "rparticle/Serialize/TransferFunctions/SerializeTransfer.h"
#include "rparticle/ParticleSystemUtils.h"
#include "rparticle/Math/Random/Random.h"
//#include "Runtime/Interfaces/IPhysics.h"
//#include "Runtime/BaseClasses/IsPlaying.h"

#define zero ZERO
#define one ONE
#define zAxis UNIT_Z

NS_RRP_BEGIN

InitialModule::InitialModule () : ParticleSystemModule(true)
,    m_GravityModifier(0.0f)
,    m_InheritVelocity(0.0f)
,    m_MaxNumParticles(1000)
{
}

Vector3f InitialModule::GetGravity (const ParticleSystemReadOnlyState& roState, const ParticleSystemState& state) const
{
#if ENABLE_PHYSICS
    //IPhysics* physicsModule = GetIPhysics();
    //if (!physicsModule)
    //    return Vector3f::zero;
    
    //Vector3f gravity = m_GravityModifier * physicsModule->GetGravity ();
    Vector3f gravity = m_GravityModifier * roState.GetRenderScale() * Vector3f(0, -9.8f, 0);
    if(roState.useLocalSpace)
    {
        Matrix4x4f worldToLocal;
        Matrix4x4f::Invert_General3D(state.localToWorld, worldToLocal);
        gravity = worldToLocal.MultiplyVector3(gravity);
    }
    return gravity;
#else
    return Vector3f::zero;
#endif
}

void InitialModule::Start (const ParticleSystemReadOnlyState& roState, const ParticleSystemState& state, ParticleSystemParticles& ps, const Matrix4x4f& matrix, size_t fromIndex, float t)
{
    DebugAssert(roState.lengthInSec > 0.0001f);
    float normalizedT = t / roState.lengthInSec;
    DebugAssert (normalizedT >= 0.0f);
    DebugAssert (normalizedT <= 1.0f);
    
    Rand& random = GetRandom();
    
    Vector3f origin = matrix.GetPosition ();
    
    auto inheritedColor = ColorRGBA32(m_InheritedValues.color);
    auto inheritedSize = m_InheritedValues.size;
    auto inheritedRotation = m_InheritedValues.rotation;
    auto lifetimeMultiplier = m_InheritedValues.lifetimeMultiplier;
    auto parentRandomSeed = m_InheritedValues.randomSeed;
    auto axisOfRotation = m_InheritedValues.axisOfRotation;
    normalizedT = m_InheritedValues.normalizedT == std::numeric_limits<float>::infinity() ? normalizedT : m_InheritedValues.normalizedT;

    const size_t count = ps.array_size ();
    for (size_t q = fromIndex; q < count; ++q)
    {
        UInt32 randUInt32 = random.Get ();
        float rand = Rand::GetFloatFromInt (randUInt32);
        UInt32 randByte = Rand::GetByteFromInt (randUInt32);
        
        ColorRGBA32 col = Evaluate (m_Color, normalizedT, randByte);
        col *= inheritedColor;
        float sz = std::max<float> (0.0f, Evaluate (m_Size, normalizedT, rand)) * roState.GetRenderScale() * inheritedSize;
        Vector3f vel = matrix.MultiplyVector3 (Vector3f::zAxis);
        float ttl = std::max<float> (0.0f, Evaluate (m_Lifetime, normalizedT, rand)) * lifetimeMultiplier;
        float rot = Evaluate (m_Rotation, normalizedT, rand) + inheritedRotation;
        
        ps.position[q] = origin;
        ps.velocity[q] = vel;
        ps.animatedVelocity[q] = Vector3f::zero;
        ps.lifetime[q] = ttl;
        ps.startLifetime[q] = ttl;
        ps.size[q] = sz;
        ps.rotation[q] = rot;
        if(ps.usesRotationalSpeed)
            ps.rotationalSpeed[q] = 0.0f;
        ps.color[q] = col;
        ps.randomSeed[q] = random.Get(); // One more iteration to avoid visible patterns between random spawned parameters and those used in update
        if(ps.usesAxisOfRotation)
            ps.axisOfRotation[q] = Vector3f::zAxis;
        for(int acc = 0; acc < ps.numEmitAccumulators; acc++)
            ps.emitAccumulator[acc][q] = 0.0f;
        
    }
}

void InitialModule::Update (const ParticleSystemReadOnlyState& roState, const ParticleSystemState& state, ParticleSystemParticles& ps, const size_t fromIndex, const size_t toIndex, float dt) const
{
    Vector3f gravityDelta = GetGravity(roState, state) * dt;
//    if (toIndex > 0)
//    {
//        CCLOG("velocity: (%f, %f, %f)", ps.velocity[0].x, ps.velocity[0].y, ps.velocity[0].z);
//    }
    if(!CompareApproximately(gravityDelta, Vector3f::zero, 0.0001f))
        for (size_t q = fromIndex; q < toIndex; ++q)
            ps.velocity[q] += gravityDelta;
    
    for (size_t q = fromIndex; q < toIndex; ++q)
        ps.animatedVelocity[q] = Vector3f::zero;
    
    if(ps.usesRotationalSpeed)
        for (size_t q = fromIndex; q < toIndex; ++q)
            ps.rotationalSpeed[q] = 0.0f;
}

void InitialModule::GenerateProcedural (const ParticleSystemReadOnlyState& roState, const ParticleSystemState& state, ParticleSystemParticles& ps, const ParticleSystemEmitReplay& emit)
{
    size_t count = emit.particlesToEmit;
    float t = emit.t;
    float alreadyPassedTime = emit.aliveTime;
    
    DebugAssert(roState.lengthInSec > 0.0001f);
    const float normalizedT = t / roState.lengthInSec;
    DebugAssert (normalizedT >= 0.0f);
    DebugAssert (normalizedT <= 1.0f);
    
    Rand& random = GetRandom();
    
    const Matrix4x4f localToWorld = !roState.useLocalSpace ? state.localToWorld : Matrix4x4f::IDENTITY;
    Vector3f origin = localToWorld.GetPosition ();
    for (size_t i = 0; i < count; ++i)
    {
        UInt32 randUInt32 = random.Get ();
        float rand = Rand::GetFloatFromInt (randUInt32);
        UInt32 randByte = Rand::GetByteFromInt (randUInt32);
        
        float frameOffset = (float(i) + emit.emissionOffset) * emit.emissionGap * float(i < emit.numContinuous);
        
        const ColorRGBA32 col = Evaluate (m_Color, normalizedT, randByte);
        float sz = std::max<float> (0.0f, Evaluate (m_Size, normalizedT, rand)) * roState.GetRenderScale();
        Vector3f vel = localToWorld.MultiplyVector3 (Vector3f::zAxis);
        float ttlStart = std::max<float> (0.0f, Evaluate (m_Lifetime, normalizedT, rand));
        float ttl = ttlStart - alreadyPassedTime - frameOffset;
        float rot = Evaluate (m_Rotation, normalizedT, rand);
        
        if (ttl < 0.0F)
            continue;
        
        size_t q = ps.array_size();
        ps.array_resize(ps.array_size() + 1);
        
        ps.position[q] = origin;
        ps.velocity[q] = vel;
        ps.animatedVelocity[q] = Vector3f::zero;
        ps.lifetime[q] = ttl;
        ps.startLifetime[q] = ttlStart;
        ps.size[q] = sz;
        ps.rotation[q] = rot;
        if(ps.usesRotationalSpeed)
            ps.rotationalSpeed[q] = 0.0f;
        ps.color[q] = col;
        ps.randomSeed[q] = random.Get(); // One more iteration to avoid visible patterns between random spawned parameters and those used in update
        if(ps.usesAxisOfRotation)
            ps.axisOfRotation[q] = Vector3f::zAxis;
        for(int acc = 0; acc < ps.numEmitAccumulators; acc++)
            ps.emitAccumulator[acc][q] = 0.0f;
    }
}

void InitialModule::CheckConsistency ()
{
    m_Lifetime.SetScalar(clamp<float> (m_Lifetime.GetScalar(), 0.05f, 100000.0f));
    m_Size.SetScalar(std::max<float> (0.0f, m_Size.GetScalar()));
    m_MaxNumParticles = std::max<int> (0, m_MaxNumParticles);
}

void InitialModule::AwakeFromLoad (RParticleSystem* system, const ParticleSystemReadOnlyState& roState)
{
    ResetSeed(roState);
}

void InitialModule::SetInheritedParams(const SubEmitterInheritValues& inheritValues)
{
    m_InheritedValues = inheritValues;
}

void InitialModule::ResetSeed(const ParticleSystemReadOnlyState& roState)
{
    if(roState.randomSeed == 0)
        m_Random.SetSeed(GetGlobalRandomSeed ());
    else
        m_Random.SetSeed(roState.randomSeed);
}

Rand& InitialModule::GetRandom()
{
#if UNITY_EDITOR
    if(!IsWorldPlaying())
        return m_EditorRandom;
    else
#endif
        return m_Random;
}

//TODO: Serialize
///*
template<class TransferFunction>
void InitialModule::Transfer (TransferFunction& transfer)
{
    SetEnabled(true); // always enabled
    ParticleSystemModule::Transfer (transfer);
    transfer.Transfer (m_Lifetime, "startLifetime");
    transfer.Transfer (m_Speed, "startSpeed");
    transfer.Transfer (m_Color, "startColor");
    transfer.Transfer (m_Size, "startSize");
    transfer.Transfer (m_Rotation, "startRotation");
    transfer.Transfer (m_GravityModifier, "gravityModifier");
    transfer.Transfer (m_InheritVelocity, "inheritVelocity");
    transfer.Transfer (m_MaxNumParticles, "maxNumParticles");
}
INSTANTIATE_TEMPLATE_TRANSFER(InitialModule)
// */

NS_RRP_END