Question

I draw text on the window by using ID3DXFont::DrawText. But when the window resized, the text stretched/shrank as well. I tried to calculate the percentage of window size changed, and apply to the font size, but it look really bizarre. I wonder if there is anyway to fixed the font size even window size is changed. Here's how I draw text:

g_pd3dDevice->Clear( 0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0,0,255), 1.0f, 0 );

if( SUCCEEDED( g_pd3dDevice->BeginScene() ) )
{
    D3DXFONT_DESC df;
    ZeroMemory(&df,sizeof(D3DXFONT_DESC));
    df.Height = 25;
    df.Width = 0;
    df.Weight = 100;
    df.MipLevels = D3DX_DEFAULT;
    df.Italic = false;
    df.CharSet = DEFAULT_CHARSET;
    df.Quality = 0;
    df.PitchAndFamily = 0;

    strcpy(df.FaceName,"Candara");
    D3DXCreateFontIndirect(g_pd3dDevice,&df,&g_font);
    RECT g_FontPosition = {0, 0, 300, 300};     
    g_font->DrawText(NULL,"Hello World",-1,&g_FontPosition,
                          DT_CENTER|DT_VCENTER,D3DCOLOR_XRGB(255,255,255));
    // End the scene
    g_pd3dDevice->EndScene();
}

g_pd3dDevice->Present( NULL, NULL, NULL, NULL );

I tried to use SetViewport method, however it didn't work. The following code shows how I manipulate direct3d. I have stuck in this issue for quite a while and completely have no clue to solve it.

STDMETHODIMP VideoRender::InitializeD3D(VOID)
{
    HRESULT hr = E_FAIL;
    D3DDISPLAYMODE d3ddm;
    D3DCAPS9 d3dcaps;
    DWORD dwCreateFlags = D3DCREATE_FPU_PRESERVE;
    D3DPRESENT_PARAMETERS d3dpp;

    m_lpD3D = Direct3DCreate9(D3D_SDK_VERSION);
    hr = IDirect3D9_GetAdapterDisplayMode(m_lpD3D, D3DADAPTER_DEFAULT, &d3ddm);
    if (m_lpD3D == NULL)
        goto error_occured;

    hr = IDirect3D9_GetAdapterDisplayMode(m_lpD3D, D3DADAPTER_DEFAULT, &d3ddm);
    if (FAILED(hr))
        goto error_occured;

    hr = IDirect3D9_GetDeviceCaps(m_lpD3D, D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, &d3dcaps);
    if (FAILED(hr))
        goto error_occured;

    if ((d3dcaps.DevCaps & D3DDEVCAPS_HWTRANSFORMANDLIGHT) == D3DDEVCAPS_HWTRANSFORMANDLIGHT)
        dwCreateFlags |= D3DCREATE_HARDWARE_VERTEXPROCESSING;
    else
        dwCreateFlags |= D3DCREATE_SOFTWARE_VERTEXPROCESSING;

    if ( (d3dcaps.StretchRectFilterCaps & D3DPTFILTERCAPS_MINFLINEAR) == D3DPTFILTERCAPS_MINFLINEAR 
        && (d3dcaps.StretchRectFilterCaps & D3DPTFILTERCAPS_MAGFLINEAR) == D3DPTFILTERCAPS_MAGFLINEAR ) {
        m_d3dfiltertype = D3DTEXF_LINEAR;
    } else
        m_d3dfiltertype = D3DTEXF_NONE;

    m_d3dformat = d3ddm.Format;

    ZeroMemory(&d3dpp, sizeof(D3DPRESENT_PARAMETERS));
    d3dpp.Windowed = TRUE;
    d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
    d3dpp.BackBufferCount = 1;
    d3dpp.BackBufferFormat = m_d3dformat;
    d3dpp.BackBufferWidth = m_dwWindowWidth;
    d3dpp.BackBufferHeight = m_dwWindowHeight;
    d3dpp.MultiSampleQuality = D3DMULTISAMPLE_NONE;
    d3dpp.PresentationInterval = D3DPRESENT_INTERVAL_DEFAULT;

    hr = IDirect3D9_CreateDevice(m_lpD3D, D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, m_hAppWindow, dwCreateFlags, &d3dpp, &m_lpDevice);
    if (FAILED(hr))
        goto error_occured;

    return S_OK;

error_occured:
    return hr;
}



STDMETHODIMP VideoRender::InitializeSwapChain(DWORD dwWidth, DWORD dwHeight)
{
    HRESULT hr = E_FAIL;
    D3DPRESENT_PARAMETERS d3dpp;
    D3DTEXTUREFILTERTYPE d3dfiltertype;
    D3DFORMAT d3dformat;
    D3DFORMAT d3dfourcc;
    D3DLOCKED_RECT LockedRect = {0};
    LPBYTE lpByte = NULL;
    LPDWORD lpdwColor = NULL;
    DWORD dwFontSize = 16;

    if (m_lpDevice == NULL)
        InitializeD3D();

    if (m_lpDevice) {
        if (dwWidth && dwHeight) {
            m_dwVideoWidth = dwWidth;
            m_dwVideoHeight = dwHeight;

            d3dfourcc = (D3DFORMAT) MAKEFOURCC('Y', 'V', '1', '2');
            d3dformat = D3DFMT_X8R8G8B8;

            ZeroMemory(&d3dpp, sizeof(D3DPRESENT_PARAMETERS));
            d3dpp.Windowed = TRUE;
            d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
            d3dpp.BackBufferWidth = m_dwVideoWidth;
            d3dpp.BackBufferHeight = m_dwVideoHeight;
            d3dpp.BackBufferFormat = d3dformat;
            d3dpp.hDeviceWindow = m_hAppWindow;

            hr = IDirect3DDevice9_CreateAdditionalSwapChain(m_lpDevice, &d3dpp, &m_lpSwapChain);
            if (FAILED(hr))
                goto error_occured;

            hr = IDirect3DDevice9_CreateOffscreenPlainSurface(m_lpDevice, m_dwVideoWidth, m_dwVideoHeight, d3dfourcc, D3DPOOL_DEFAULT, &m_lpSurface, NULL);
            if (FAILED(hr))
                goto error_occured;

            hr = IDirect3D9_CheckDeviceFormat(m_lpD3D, D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, m_d3dformat, D3DUSAGE_QUERY_FILTER, D3DRTYPE_TEXTURE, d3dformat);
            if (FAILED(hr))
                d3dfiltertype = D3DTEXF_NONE;
            else
                d3dfiltertype = m_d3dfiltertype;

            m_d3dfiltertype = d3dfiltertype;
            m_d3dformat = d3dformat;
            m_d3dfourcc = d3dfourcc;

            hr = IDirect3DDevice9_CreateTexture(m_lpDevice, 2048, 2048, 1, D3DUSAGE_DYNAMIC, D3DFMT_A8R8G8B8, D3DPOOL_DEFAULT, &m_lpTexture, NULL);
            IDirect3DTexture9_LockRect(m_lpTexture, 0, &LockedRect, NULL, D3DLOCK_DISCARD);
            lpByte = (LPBYTE) LockedRect.pBits;
            lpdwColor = (LPDWORD) lpByte;
            memset(lpByte, 0xff, 2048 * 2048 * 4);
            IDirect3DTexture9_UnlockRect(m_lpTexture, 0);

            hr = D3DXCreateSprite(m_lpDevice, &m_lpSprite);
            if (FAILED(hr)) {
            }

            hr = D3DXCreateFont(m_lpDevice, dwFontSize, 0, FW_BOLD, 0, FALSE, DEFAULT_CHARSET, OUT_DEFAULT_PRECIS, DEFAULT_QUALITY, DEFAULT_PITCH | FF_DONTCARE, L"Consolas", &m_lpInfoFont);
            if (FAILED(hr)) {
            }

            m_bInitedSwapChain = TRUE;
        }
    }

    return S_OK;

error_occured:
    return hr;
}



STDMETHODIMP VideoRender::Update(LPBYTE lpBuffer)
{
    HRESULT hr = S_OK;
    LPDIRECT3DSURFACE9 lpBackBuffer = NULL;
    DWORD dwWidth = 0;
    DWORD dwHeight = 0;
    D3DPRESENT_PARAMETERS d3dpp;


    if (lpPluginBuffer) {
        EnterCriticalSection(&m_csSwapChain);
        if (m_lpSwapChain) {
            IDirect3DSwapChain9_GetPresentParameters(m_lpSwapChain, &d3dpp);

            hr = IDirect3DSwapChain9_GetBackBuffer(m_lpSwapChain, 0, D3DBACKBUFFER_TYPE_MONO, &lpBackBuffer);
            hr = IDirect3DDevice9_SetRenderTarget(m_lpDevice, 0, lpBackBuffer);
            hr = IDirect3DSurface9_Release(lpBackBuffer);
            hr = IDirect3DDevice9_Clear(m_lpDevice, 0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0, 0, 0), 1.0f, 0);

            hr = IDirect3DDevice9_BeginScene(m_lpDevice);
            if (SUCCEEDED(hr)) {
                D3DLOCKED_RECT LockedRect;
                LPBYTE source = 0, dest = 0;

                ZeroMemory(&LockedRect, sizeof(D3DLOCKED_RECT));
                hr = IDirect3DSurface9_LockRect(m_lpSurface, &LockedRect, NULL, 0);
                dest = (LPBYTE) LockedRect.pBits;
                source = lpPluginBuffer->lpBuffer;
                if (SUCCEEDED(hr) && dest) {
                    /* copy image buffer to LockedRect */
                }
                IDirect3DSurface9_UnlockRect(m_lpSurface);
                hr = IDirect3DDevice9_StretchRect(m_lpDevice, m_lpSurface, lprtSrc, lpBackBuffer, lprtDest, D3DTEXF_LINEAR);

                m_lpSprite->Begin(D3DXSPRITE_ALPHABLEND);
                pos.x = 0;
                pos.y = 0;
                pos.z = 0;

                SetRect(&rt, 0, 0, 100, 100);
                m_lpInfoFont->DrawTextW(m_lpSprite, L"test", -1, &rt, DT_VCENTER, D3DCOLOR_RGBA(0, 255, 255, 0xff));
                m_lpSprite->End();
            }
            hr = IDirect3DDevice9_EndScene(m_lpDevice);
            hr = IDirect3DSwapChain9_Present(m_lpSwapChain, NULL, NULL, NULL, NULL, 0);
        }
        LeaveCriticalSection(&m_csSwapChain);
    }

    return S_OK;
}

Thanks a lot, this really help a lot.

But if I create a swap chain with different resolution backbuffer from window size (either greater or small). And rendering some images to the window, it automatically re-size the images to fit the window size. Seemed the Viewport has been changed due to different size. The drawn text would be stretched/shrank as well. Is there any way to prevent this from happening?

I want the overlay text not to be affected by anything else.

Was it helpful?

Solution

You have to reset the Direct3D device each time the size of the window changes.

Use IDirect3DDevice9::Reset method. Remember to release all resources created in the default pool first.

You should check for WM_SIZE in window message loop in order to determine if the window's size has changed.

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