#include <windows.h>
#include <d3d9.h>
#include <D3DX9Mesh.h>

#define THROW_ERROR_AND_EXIT(x) { \
    MessageBox(0,x,0,0); \
    return -1; \
    }

LRESULT CALLBACK WndProc( HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam )
{
    // Handle close event
    switch( msg )
    {
    case WM_DESTROY:
        PostQuitMessage( 0 );
        return 0;
    }
    return DefWindowProc( hWnd, msg, wParam, lParam );
}

int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    // Registering class
    WNDCLASSEX wcex;

    wcex.cbSize = sizeof(WNDCLASSEX); 
    wcex.style= CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc= (WNDPROC)WndProc;
    wcex.cbClsExtra= 0;
    wcex.cbWndExtra= 0;
    wcex.hInstance= hInstance;
    wcex.hIcon= 0;
    wcex.hCursor= LoadCursor(NULL, IDC_ARROW);
    wcex.hbrBackground= (HBRUSH)(COLOR_WINDOW+1);
    wcex.lpszMenuName= 0;
    wcex.lpszClassName= "MyMeshViewer";
    wcex.hIconSm= 0;

    RegisterClassEx(&wcex);

    // Creating Window
    HWND hWnd = CreateWindow("MyMeshViewer", "MyMeshViewer", WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInstance, NULL);

    // Creating Direct3D object
    LPDIRECT3D9 d3dObject=NULL;
    LPDIRECT3DDEVICE9 d3dDevice=NULL;

    d3dObject=Direct3DCreate9(D3D_SDK_VERSION);

    // Creating Direct3D device
    if(NULL == d3dObject)
        THROW_ERROR_AND_EXIT("NULL == d3dObject");
    D3DPRESENT_PARAMETERS presParams;
    ZeroMemory(&presParams,sizeof(presParams));
    presParams.Windowed=TRUE;
    presParams.SwapEffect=D3DSWAPEFFECT_DISCARD;
    presParams.BackBufferFormat=D3DFMT_UNKNOWN;
    presParams.PresentationInterval=D3DPRESENT_INTERVAL_ONE;
    HRESULT hr=d3dObject->CreateDevice(D3DADAPTER_DEFAULT,D3DDEVTYPE_HAL,hWnd, D3DCREATE_HARDWARE_VERTEXPROCESSING, &presParams, &d3dDevice);
    if(FAILED(hr))
        THROW_ERROR_AND_EXIT("d3dObject->CreateDevice");

    // Loading the mesh
    LPD3DXBUFFER materialBuffer = NULL;
    DWORD numMaterials = 0;
    LPD3DXMESH mesh = NULL;
    hr=D3DXLoadMeshFromX("d:\\temp\\tiger.x", D3DXMESH_SYSTEMMEM, 
        d3dDevice, NULL, 
        &materialBuffer,NULL, &numMaterials, 
        &mesh );
    if(FAILED(hr))
        THROW_ERROR_AND_EXIT("hr=D3DXLoadMeshFromX");

    // Loading the material buffer
    D3DXMATERIAL* d3dxMaterials = (D3DXMATERIAL*)materialBuffer->GetBufferPointer();
    // Holding material and texture pointers
    D3DMATERIAL9 *meshMaterials = new D3DMATERIAL9[numMaterials];
    LPDIRECT3DTEXTURE9 *meshTextures  = new LPDIRECT3DTEXTURE9[numMaterials];   
    // Filling material and texture arrays
    for (DWORD i=0; i<numMaterials; i++)
    {
        // Copy the material
        meshMaterials[i] = d3dxMaterials[i].MatD3D;

        // Set the ambient color for the material (D3DX does not do this)
        meshMaterials[i].Ambient = meshMaterials[i].Diffuse;

        // Create the texture if it exists - it may not
        meshTextures[i] = NULL;
        if (d3dxMaterials[i].pTextureFilename)
            D3DXCreateTextureFromFile(d3dDevice, d3dxMaterials[i].pTextureFilename, &meshTextures[i]);
    }

    materialBuffer->Release();

    // Show Window
    ShowWindow(hWnd, nCmdShow);
    UpdateWindow(hWnd);

    // Handle messages
    MSG msg;
    ZeroMemory( &msg, sizeof(msg) );
    while( msg.message!=WM_QUIT )
    {
        if( PeekMessage( &msg, NULL, 0U, 0U, PM_REMOVE ) )
        {
            TranslateMessage( &msg );
            DispatchMessage( &msg );
        }
        else
        {
            // Rendering
            d3dDevice->Clear(0,NULL,D3DCLEAR_TARGET, D3DCOLOR_XRGB(255,255,255),1.0f,0);
            // Turn on wireframe mode
	        d3dDevice->SetRenderState(D3DRS_FILLMODE,D3DFILL_WIREFRAME);
            d3dDevice->BeginScene();

            for (DWORD i=0; i<numMaterials; i++)
            {
                // Set the material and texture for this subset
                d3dDevice->SetMaterial(&meshMaterials[i]);
                d3dDevice->SetTexture(0,meshTextures[i]);
                // Draw the mesh subset
                mesh->DrawSubset( i );
            }

            d3dDevice->EndScene();
            d3dDevice->Present(NULL, NULL, NULL, NULL);
            Sleep(0);
        }
    }
    return (int)msg.wParam;
}