C++ LPDIRECT3DDEVICE7::GetRenderTarget方法代码示例

//.........这里部分代码省略.........
    ddsd.dwWidth         = m_dwWidth;
    ddsd.dwHeight        = m_dwHeight;

    // Turn on texture management for hardware devices
    if( ddDesc.deviceGUID == IID_IDirect3DHALDevice )
        ddsd.ddsCaps.dwCaps2 = DDSCAPS2_TEXTUREMANAGE;
    else if( ddDesc.deviceGUID == IID_IDirect3DTnLHalDevice )
        ddsd.ddsCaps.dwCaps2 = DDSCAPS2_TEXTUREMANAGE;
    else
        ddsd.ddsCaps.dwCaps |= DDSCAPS_SYSTEMMEMORY;

    // Adjust width and height to be powers of 2, if the device requires it
    if( ddDesc.dpcTriCaps.dwTextureCaps & D3DPTEXTURECAPS_POW2 )
    {
        for( ddsd.dwWidth=1;  m_dwWidth>ddsd.dwWidth;   ddsd.dwWidth<<=1 );
        for( ddsd.dwHeight=1; m_dwHeight>ddsd.dwHeight; ddsd.dwHeight<<=1 );
    }

    // Limit max texture sizes, if the driver can't handle large textures
    DWORD dwMaxWidth  = ddDesc.dwMaxTextureWidth;
    DWORD dwMaxHeight = ddDesc.dwMaxTextureHeight;
    ddsd.dwWidth  = min( ddsd.dwWidth,  ( dwMaxWidth  ? dwMaxWidth  : 256 ) );
    ddsd.dwHeight = min( ddsd.dwHeight, ( dwMaxHeight ? dwMaxHeight : 256 ) );

    // Make the texture square, if the driver requires it
    if( ddDesc.dpcTriCaps.dwTextureCaps & D3DPTEXTURECAPS_SQUAREONLY )
    {
        if( ddsd.dwWidth > ddsd.dwHeight ) ddsd.dwHeight = ddsd.dwWidth;
        else                               ddsd.dwWidth  = ddsd.dwHeight;
    }

    // Setup the structure to be used for texture enumration.
    TEXTURESEARCHINFO tsi;
    tsi.bFoundGoodFormat = FALSE;
    tsi.pddpf            = &ddsd.ddpfPixelFormat;
    tsi.dwDesiredBPP     = m_dwBPP;
    tsi.bUsePalette      = ( m_dwBPP <= 8 );
    tsi.bUseAlpha        = m_bHasMyAlpha;
    if( m_dwFlags & D3DTEXTR_16BITSPERPIXEL )
        tsi.dwDesiredBPP = 16;
    else if( m_dwFlags & D3DTEXTR_32BITSPERPIXEL )
        tsi.dwDesiredBPP = 32;

    if( m_dwFlags & (D3DTEXTR_TRANSPARENTWHITE|D3DTEXTR_TRANSPARENTBLACK) )
    {
        if( tsi.bUsePalette )
        {
            if( ddDesc.dpcTriCaps.dwTextureCaps & D3DPTEXTURECAPS_ALPHAPALETTE )
            {
                tsi.bUseAlpha   = TRUE;
                tsi.bUsePalette = TRUE;
            }
            else
            {
                tsi.bUseAlpha   = TRUE;
                tsi.bUsePalette = FALSE;
            }
        }
    }

    // Enumerate the texture formats, and find the closest device-supported
    // texture pixel format
    pd3dDevice->EnumTextureFormats( TextureSearchCallback, &tsi );

    // If we couldn't find a format, let's try a default format
    if( FALSE == tsi.bFoundGoodFormat )
    {
        tsi.bUsePalette  = FALSE;
        tsi.dwDesiredBPP = 16;
        pd3dDevice->EnumTextureFormats( TextureSearchCallback, &tsi );

        // If we still fail, we cannot create this texture
        if( FALSE == tsi.bFoundGoodFormat )
            return E_FAIL;
    }

    // Get the DirectDraw interface for creating surfaces
    LPDIRECTDRAW7        pDD;
    LPDIRECTDRAWSURFACE7 pddsRender;
    pd3dDevice->GetRenderTarget( &pddsRender );
    pddsRender->GetDDInterface( (VOID**)&pDD );
    pddsRender->Release();

    // Create a new surface for the texture
    HRESULT hr = pDD->CreateSurface( &ddsd, &m_pddsSurface, NULL );

    // Done with DDraw
    pDD->Release();

    if( FAILED(hr) )
        return hr;

    // For bitmap-based textures, copy the bitmap image.
    if( m_hbmBitmap )
        return CopyBitmapToSurface();

    // At this point, code can be added to handle other file formats (such as
    // .dds files, .jpg files, etc.).
    return S_OK;
}