loading images to the backbuffer / direct3d / c++

Question

these are the variables:

std::wstring        wsPath = L"./LIFE.bmp"; // path to the image
IDirect3DSurface9   *Surface = NULL;    // image surface
IDirect3DSurface9   *BackBuffer = NULL; // back buffer surface

and this is the render() function:

void render(void)
{
    // Check to make sure you have a valid Direct3D device
    if (NULL == pd3dDevice) return;

    pd3dDevice -> Clear(0, NULL, D3DCLEAR_TARGET, D3DCOLOR_XRGB(0, 0, 255), 1.0f, 0);   // clear the back buffer to a blue color

    if (SUCCEEDED(pd3dDevice -> BeginScene()))
    {
        D3DXIMAGE_INFO Info;

        D3DXGetImageInfoFromFile(wsPath.c_str(), &Info);
        pd3dDevice -> CreateOffscreenPlainSurface(Info.Width, Info.Height, Info.Format, D3DPOOL_SYSTEMMEM, &Surface, NULL);

        D3DXLoadSurfaceFromFile(Surface, NULL, NULL, wsPath.c_str(), NULL, D3DX_FILTER_NONE, 0, NULL);

        pd3dDevice -> GetBackBuffer(0, 0, D3DBACKBUFFER_TYPE_MONO, &BackBuffer);
        pd3dDevice -> UpdateSurface(Surface, NULL, BackBuffer, NULL);

        // End the scene
        pd3dDevice -> EndScene();
    }

    // Present the back buffer contents to the display
    pd3dDevice -> Present(NULL, NULL, NULL, NULL);
}

i keep getting this strange error:

1>DIRECTX_001.obj : error LNK2019: unresolved external symbol _D3DXLoadSurfaceFromFileW@32 referenced in function "void __cdecl render(void)" (?render@@YAXXZ)
1>DIRECTX_001.obj : error LNK2019: unresolved external symbol _D3DXGetImageInfoFromFileW@8 referenced in function "void __cdecl render(void)" (?render@@YAXXZ)

Can you explain to me what is happening here? Thank you!

Answer 1

The linker is letting you know that it can't find the function D3DXLoadSurfaceFromFile and D3DXGetImageInfoFromFile.

Check your linker settings to make sure that you including the required libs.

The library in question is D3dx9.lib.