/*---------------------------------------------------------------------------*
  Project:  NintendoWare
  File:     gfx_LookAtTargetViewUpdater.cpp
  
  Copyright (C)2009-2011 Nintendo/HAL Laboratory, Inc.  All rights reserved.
  
  These coded instructions, statements, and computer programs contain proprietary
  information of Nintendo and/or its licensed developers and are protected by
  national and international copyright laws. 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.
  
  The content herein is highly confidential and should be handled accordingly.
  
  $Revision: 31311 $
 *---------------------------------------------------------------------------*/

#include "precompiled.h"
#include <nw/gfx/gfx_LookAtTargetViewUpdater.h>
#include <nw/os/os_Memory.h>

namespace nw
{
namespace gfx
{

NW_UT_RUNTIME_TYPEINFO_DEFINITION(LookAtTargetViewUpdater, CameraViewUpdater);

//----------------------------------------
LookAtTargetViewUpdater*
LookAtTargetViewUpdater::Create(os::IAllocator* allocator)
{
    NW_NULL_ASSERT(allocator);
    
    void* updaterMemory = allocator->Alloc(sizeof(LookAtTargetViewUpdater));
    NW_NULL_ASSERT(updaterMemory);

    void* dataMemory
        = AllocateAndFill<ResLookAtTargetViewUpdaterData>(allocator, 0);

    ResLookAtTargetViewUpdaterData* buffer =
            new(dataMemory) ResLookAtTargetViewUpdaterData();
    
    buffer->typeInfo         = ResLookAtTargetViewUpdater::TYPE_INFO;
    buffer->m_TargetPosition = VIEW_TARGET_POSITION;
    buffer->m_UpwardVector   = VIEW_UPWARD_VECTOR;
    buffer->m_Flags          = 0x0;

    ResLookAtTargetViewUpdater resUpdater = ResLookAtTargetViewUpdater(buffer);

    return new(updaterMemory) LookAtTargetViewUpdater(allocator, true, resUpdater);
}

//----------------------------------------
LookAtTargetViewUpdater*
LookAtTargetViewUpdater::Create(os::IAllocator* allocator, ResLookAtTargetViewUpdater resUpdater)
{
    NW_NULL_ASSERT(allocator);
    
    void* updaterMemory = allocator->Alloc(sizeof(LookAtTargetViewUpdater));
    NW_NULL_ASSERT(updaterMemory);

    return new(updaterMemory) LookAtTargetViewUpdater(allocator, false, resUpdater);
}

//----------------------------------------
LookAtTargetViewUpdater::LookAtTargetViewUpdater(
    os::IAllocator* allocator,
    bool isDynamic,
    ResLookAtTargetViewUpdater resUpdater)
: CameraViewUpdater(allocator, isDynamic),
  m_Resource(resUpdater)
{
}

//----------------------------------------
LookAtTargetViewUpdater::~LookAtTargetViewUpdater()
{
    if (this->IsDynamic() && this->m_Resource.IsValid())
    {
        this->GetAllocator().Free(m_Resource.ptr());
    }
}

//----------------------------------------
void 
LookAtTargetViewUpdater::Update(
                                math::MTX34* viewMatrix,
                                const math::MTX34& worldMatrix,
                                const math::VEC3& cameraPosition)
{
    NW_ASSERT(m_Resource.IsValid());

    u32 flags = m_Resource.GetFlags();
    math::VEC3 targetPosition(this->m_Resource.GetTargetPosition());
    math::VEC3 upwardVector(this->m_Resource.GetUpwardVector());

    if (ut::CheckFlagOr(
            flags,
            ResLookAtTargetViewUpdaterData::FLAG_INHERITING_TARGET_ROTATE |
            ResLookAtTargetViewUpdaterData::FLAG_INHERITING_TARGET_TRANSLATE |
            ResLookAtTargetViewUpdaterData::FLAG_INHERITING_UP_ROTATE))
    {
        math::MTX33 rotateMatrix;
        math::MTX34ToMTX33(&rotateMatrix, &worldMatrix);

        if (ut::CheckFlag(flags, ResLookAtTargetViewUpdaterData::FLAG_INHERITING_UP_ROTATE))
        {
            math::VEC3Transform(&upwardVector, &rotateMatrix, &upwardVector);
        }
        if (ut::CheckFlag(flags, ResLookAtTargetViewUpdaterData::FLAG_INHERITING_TARGET_ROTATE))
        {
            math::VEC3Transform(&targetPosition, &rotateMatrix, &targetPosition);
        }
        if (ut::CheckFlag(flags, ResLookAtTargetViewUpdaterData::FLAG_INHERITING_TARGET_TRANSLATE))
        {
            math::VEC3Add(&targetPosition, &targetPosition, &cameraPosition);
        }
    }

    NW_ASSERT(cameraPosition != targetPosition);
    NW_ASSERT(!upwardVector.IsZero());

    // 視線ベクトルとアップベクトルが平行ではいけない
    NW_ASSERT(!math::VEC3().Cross(upwardVector, targetPosition - cameraPosition).IsZero());

    math::MTX34LookAt(
            viewMatrix,
            &cameraPosition,
            &upwardVector,
            &targetPosition);
}

} // namespace gfx
} // namespace nw