void PhysicsMesh::DefineInputlayout()
{
    m_VertexBufferStride = sizeof(float3);
    // Define the input layout
    D3D10_INPUT_ELEMENT_DESC layout[] =
    {
        { "POSITION", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, 0, D3D10_INPUT_PER_VERTEX_DATA, 0 },
    };
    UINT numElements = sizeof(layout)/sizeof(layout[0]);

    // Create the input layout
    D3D10_PASS_DESC PassDesc;
    // Get the pass descriptor from the effect technique
    m_pDefaultTechnique->GetPassByIndex(0)->GetDesc(&PassDesc);
    m_pLevel->GetDevice()->CreateInputLayout(layout, numElements, PassDesc.pIAInputSignature, PassDesc.IAInputSignatureSize, &m_pVertexLayout);
}

void PhysicsMesh::BuildIndexBuffer()
{
    MIT meshIt = m_Meshes.begin();
    for(meshIt; meshIt != m_Meshes.end(); ++meshIt){
        m_NumIndices = (*meshIt)->GetNumFaces()*3;

        ID3D10Buffer *buffer;
        D3D10_BUFFER_DESC bd;
        bd.Usage = D3D10_USAGE_DEFAULT;
        bd.ByteWidth = sizeof(float3) * (*meshIt)->GetNumFaces() *3;
        bd.BindFlags = D3D10_BIND_INDEX_BUFFER;
        bd.CPUAccessFlags = 0;
        bd.MiscFlags = 0;

        D3D10_SUBRESOURCE_DATA initData;
        initData.pSysMem = (*meshIt)->GetTrianglesPointer();

        HR(m_pLevel->GetDevice()->CreateBuffer(&bd, &initData, &buffer));
        m_pIndexBuffers.push_back(buffer);
    }
}

void PhysicsMesh::BuildVertexBuffer()
{
    MIT meshIt = m_Meshes.begin();
    for(meshIt; meshIt != m_Meshes.end(); ++meshIt){
        ID3D10Buffer *buffer;
        D3D10_BUFFER_DESC bd;
        bd.Usage = D3D10_USAGE_DEFAULT;
        bd.ByteWidth = sizeof(float3) * (*meshIt)->GetNumVertices();
        bd.BindFlags = D3D10_BIND_VERTEX_BUFFER;
        bd.CPUAccessFlags = 0;
        bd.MiscFlags = 0;

        D3D10_SUBRESOURCE_DATA initData;
        initData.pSysMem = (*meshIt)->GetVertexPointer();

        HR(m_pLevel->GetDevice()->CreateBuffer(&bd, &initData, &buffer));
        m_pVertexBuffers.push_back(buffer);
    }
}

void PhysicsMesh::Initialize(ContentManager *pContentManager)
{
    CreateEffect(pContentManager);

    ObjPhysicsReader *physRdr = new ObjPhysicsReader(m_filename);
    physRdr->Read();

    m_Meshes.assign(physRdr->GetInputMeshBegin(), physRdr->GetInputMeshEnd());

    delete physRdr;

    DefineInputlayout();
    BuildVertexBuffer();
    BuildIndexBuffer();
    Rotate(D3DXVECTOR3(-1.57079633f,0,0));

    if(m_Type == Concave)
        BuildConcave();
    else
        BuildConvex();
}

void PhysicsMesh::Draw(const RenderContext* pRenderContext)
{
    // Update Shader matrix variables
    D3DXMATRIX matView = pRenderContext->GetCamera()->GetView();
    D3DXMATRIX matProj = pRenderContext->GetCamera()->GetProj();
    m_pWorldViewProjectionVariable->SetMatrix((float*)&(m_World*matView*matProj));

    // Set the input layout
    m_pLevel->GetDevice()->IASetInputLayout(m_pVertexLayout);

    for(UINT i = 0; i < m_pVertexBuffers.size(); ++i){
        // Set vertex buffer(s)
        UINT offset = 0;
        m_pLevel->GetDevice()->IASetVertexBuffers( 0, 1, &m_pVertexBuffers.at(i), &m_VertexBufferStride, &offset);

        // Set index buffer
        m_pLevel->GetDevice()->IASetIndexBuffer(m_pIndexBuffers.at(i), DXGI_FORMAT_R32_UINT, 0);

        // Set primitive topology
        m_pLevel->GetDevice()->IASetPrimitiveTopology(D3D10_PRIMITIVE_TOPOLOGY_TRIANGLELIST);

        D3D10_TECHNIQUE_DESC techDesc;
        m_pDefaultTechnique->GetDesc( &techDesc );
        for( UINT p = 0; p < techDesc.Passes; ++p )
        {
            m_pDefaultTechnique->GetPassByIndex(p)->Apply(0);
            m_pLevel->GetDevice()->DrawIndexed(m_NumIndices, 0, 0 );
        }
    }
}