trianglefan.cpp

//-----------------------------------------------------------------------------
// File: TriangleFan.cpp
//
// This is based on Vertices.cpp, and it draws a Triangle Fan from the Engel
// book.
//-----------------------------------------------------------------------------
#include <d3d9.h>
#pragma warning( disable : 4996 ) // disable deprecated warning
#include <strsafe.h>
#pragma warning( default : 4996 )




//-----------------------------------------------------------------------------
// Global variables
//-----------------------------------------------------------------------------
LPDIRECT3D9             g_pD3D = NULL; // Used to create the D3DDevice
LPDIRECT3DDEVICE9       g_pd3dDevice = NULL; // Our rendering device
LPDIRECT3DVERTEXBUFFER9 g_pVB = NULL; // Buffer to hold Vertices

// A structure for our custom vertex type
struct CUSTOMVERTEX
{
    FLOAT x, y, z, rhw; // The transformed position for the vertex
    DWORD color;        // The vertex color
};

// Our custom FVF, which describes our custom vertex structure
#define D3DFVF_CUSTOMVERTEX (D3DFVF_XYZRHW|D3DFVF_DIFFUSE)




//-----------------------------------------------------------------------------
// Name: InitD3D()
// Desc: Initializes Direct3D
//-----------------------------------------------------------------------------
HRESULT InitD3D( HWND hWnd )
{
    // Create the D3D object.
    if( NULL == ( g_pD3D = Direct3DCreate9( D3D_SDK_VERSION ) ) )
        return E_FAIL;

    // Set up the structure used to create the D3DDevice
    D3DPRESENT_PARAMETERS d3dpp;
    ZeroMemory( &d3dpp, sizeof( d3dpp ) );
    d3dpp.Windowed = TRUE;
    d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
    d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;

    // Create the D3DDevice
    if( FAILED( g_pD3D->CreateDevice( D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hWnd,
                                      D3DCREATE_SOFTWARE_VERTEXPROCESSING,
                                      &d3dpp, &g_pd3dDevice ) ) )
    {
        return E_FAIL;
    }

    // Device state would normally be set here

    return S_OK;
}


//-----------------------------------------------------------------------------
// Name: InitVB()
// Desc: Creates a vertex buffer and fills it with our Vertices. The vertex
//       buffer is basically just a chuck of memory that holds Vertices. After
//       creating it, we must Lock()/Unlock() it to fill it. For indices, D3D
//       also uses index buffers. The special thing about vertex and index
//       buffers is that they can be created in device memory, allowing some
//       cards to process them in hardware, resulting in a dramatic
//       performance gain.
//-----------------------------------------------------------------------------
HRESULT InitVB()
{
    // Initialize three Vertices for rendering a triangle
        // NOTE: 1-4-3-2 produces the "fan", with default CULLMODE (CCW)
        // NOTE: 1-4-2-3 produces ONE triangle, with the other one "hidden" (or culled). If you
        // set RenderState(D3DRS_CULLMODE, D3DCULL_CW), you'll see the 1-2-3 triangle. If you set
        // RenderState(D3DRS_CULLMODE, D3DCULL_NONE) you will see BOTH triangles, with the 1-2-3 triangle "folded in"
        // NOTE: 1-2-3-4 will ONLY work if you set RenderState(D3DRS_CULLMODE, D3DCULL_NONE) or RenderState(D3DRS_CULLMODE, D3DCULL_CW)
    CUSTOMVERTEX Vertices[] =
    {
                { 109.0f,  43.0f, 0.5f, 1.0f, 0xffff0000, }, // 1: x, y, z, rhw, color // red
                { 192.0f, 205.0f, 0.5f, 1.0f, 0xffffff00, }, // 4:          
                { 101.0f, 250.0f, 0.5f, 1.0f, 0xff00ffff, }, // 3: blue
                { 26.0f,  204.0f, 0.5f, 1.0f, 0xff00ff00, }, // 2: green
               
    };

    // Create the vertex buffer. Here we are allocating enough memory
    // (from the default pool) to hold all our 3 custom Vertices. We also
    // specify the FVF, so the vertex buffer knows what data it contains.
    if( FAILED( g_pd3dDevice->CreateVertexBuffer( 4 * sizeof( CUSTOMVERTEX ),
                                                  0, D3DFVF_CUSTOMVERTEX,
                                                  D3DPOOL_DEFAULT, &g_pVB, NULL ) ) )
    {
        return E_FAIL;
    }

    // Now we fill the vertex buffer. To do this, we need to Lock() the VB to
    // gain access to the Vertices. This mechanism is required becuase vertex
    // buffers may be in device memory.
    VOID* pVertices;
    if( FAILED( g_pVB->Lock( 0, sizeof( Vertices ), ( void** )&pVertices, 0 ) ) )
        return E_FAIL;
    memcpy( pVertices, Vertices, sizeof( Vertices ) );
    g_pVB->Unlock();

    return S_OK;
}




//-----------------------------------------------------------------------------
// Name: Cleanup()
// Desc: Releases all previously initialized objects
//-----------------------------------------------------------------------------
VOID Cleanup()
{
    if( g_pVB != NULL )
        g_pVB->Release();

    if( g_pd3dDevice != NULL )
        g_pd3dDevice->Release();

    if( g_pD3D != NULL )
        g_pD3D->Release();
}




//-----------------------------------------------------------------------------
// Name: Render()
// Desc: Draws the scene
//-----------------------------------------------------------------------------
VOID Render()
{
    g_pd3dDevice->Clear( 0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB( 0, 0, 0 ), 1.0f, 0 );

    // Begin the scene
    if( SUCCEEDED( g_pd3dDevice->BeginScene() ) )
    {
                g_pd3dDevice->SetRenderState( D3DRS_FILLMODE, D3DFILL_SOLID ); // NOTE: Added
                // g_pd3dDevice->SetRenderState( D3DRS_CULLMODE, D3DCULL_NONE); // NOTE: Added (D3DCULL_CCW is default)
        g_pd3dDevice->SetStreamSource( 0, g_pVB, 0, sizeof( CUSTOMVERTEX ) );
        g_pd3dDevice->SetFVF( D3DFVF_CUSTOMVERTEX );
                g_pd3dDevice->DrawPrimitive( D3DPT_TRIANGLEFAN, 0, 2 );

        // End the scene
        g_pd3dDevice->EndScene();
    }

    // Present the backbuffer contents to the display
    g_pd3dDevice->Present( NULL, NULL, NULL, NULL );
}




//-----------------------------------------------------------------------------
// Name: MsgProc()
// Desc: The window's message handler
//-----------------------------------------------------------------------------
LRESULT WINAPI MsgProc( HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam )
{
    switch( msg )
    {
        case WM_DESTROY:
            Cleanup();
            PostQuitMessage( 0 );
            return 0;
    }

    return DefWindowProc( hWnd, msg, wParam, lParam );
}




//-----------------------------------------------------------------------------
// Name: wWinMain()
// Desc: The application's entry point
//-----------------------------------------------------------------------------
INT WINAPI wWinMain( HINSTANCE hInst, HINSTANCE, LPWSTR, INT )
{
    // Register the window class
    WNDCLASSEX wc =
    {
        sizeof( WNDCLASSEX ), CS_CLASSDC, MsgProc, 0L, 0L,
        GetModuleHandle( NULL ), NULL, NULL, NULL, NULL,
        L"TriangleFan", NULL
    };
    RegisterClassEx( &wc );

    // Create the application's window
        HWND hWnd = CreateWindow( L"TriangleFan", L"Triangle Fan: Demo",
                              WS_OVERLAPPEDWINDOW, 100, 100, 300, 300,
                              NULL, NULL, wc.hInstance, NULL );

    // Initialize Direct3D
    if( SUCCEEDED( InitD3D( hWnd ) ) )
    {
        // Create the vertex buffer
        if( SUCCEEDED( InitVB() ) )
        {
            // Show the window
            ShowWindow( hWnd, SW_SHOWDEFAULT );
            UpdateWindow( hWnd );

            // Enter the message loop
            MSG msg;
            ZeroMemory( &msg, sizeof( msg ) );
            while( msg.message != WM_QUIT )
            {
                if( PeekMessage( &msg, NULL, 0U, 0U, PM_REMOVE ) )
                {
                    TranslateMessage( &msg );
                    DispatchMessage( &msg );
                }
                else
                    Render();
            }
        }
    }

    UnregisterClass( L"TriangleFan", wc.hInstance );
    return 0;
}