Paint to a bitmap using DirectX under Windows Metro - directx

Question

I am trying to use DirectX to create and paint into a bitmap, and then later use that bitmap to paint to the screen. I have the following test code which I have pieced together from a number of sources. I seem to be able to create the bitmap without errors, and I try and fill it with red. However, when I use the bitmap to paint to the screen I just get a black rectangle. Can anyone tell me what I might be doing wrong? Note that this is running as a Windows 8 Metro app, if that makes a difference.
Note that the formatter seems to be removing my angle brackets and I don't how stop it from doing that. The 'device' variable is of class ID3D11Device, the 'context' variable is ID3D11DeviceContext, the d2dContext variable is ID2D1DeviceContext, the dgixDevice variable is IDXGIDevice, and the 'd2dDevice' is ID2D1Device.
void PaintTestBitmap(GRectF& rect)
{
HRESULT hr;
UINT creationFlags = D3D11_CREATE_DEVICE_BGRA_SUPPORT;
D3D_FEATURE_LEVEL featureLevels[] =
{
D3D_FEATURE_LEVEL_11_1,
D3D_FEATURE_LEVEL_11_0,
D3D_FEATURE_LEVEL_10_1,
D3D_FEATURE_LEVEL_10_0,
D3D_FEATURE_LEVEL_9_3,
D3D_FEATURE_LEVEL_9_2,
D3D_FEATURE_LEVEL_9_1
};
ComPtr<ID3D11Device> device;
ComPtr<ID3D11DeviceContext> context;
ComPtr<ID2D1DeviceContext> d2dContext;
hr = D3D11CreateDevice( NULL,
D3D_DRIVER_TYPE_HARDWARE,
NULL,
creationFlags,
featureLevels,
ARRAYSIZE(featureLevels),
D3D11_SDK_VERSION,
&device,
NULL,
&context);
if (SUCCEEDED(hr))
{
ComPtr<IDXGIDevice> dxgiDevice;
device.As(&dxgiDevice);
// create D2D device context
ComPtr<ID2D1Device> d2dDevice;
hr = D2D1CreateDevice(dxgiDevice.Get(), NULL, &d2dDevice);
if (SUCCEEDED(hr))
{
hr = d2dDevice->CreateDeviceContext(D2D1_DEVICE_CONTEXT_OPTIONS_NONE, &d2dContext);
if (SUCCEEDED(hr))
{
ID2D1Bitmap1 *pBitmap;
D2D1_SIZE_U size = { rect.m_width, rect.m_height };
D2D1_BITMAP_PROPERTIES1 properties = {{ DXGI_FORMAT_R8G8B8A8_UNORM, D2D1_ALPHA_MODE_PREMULTIPLIED }, 96, 96, D2D1_BITMAP_OPTIONS_TARGET, 0 };
hr = d2dContext->CreateBitmap(size, (const void *) 0, 0, &properties, &pBitmap);
if (SUCCEEDED(hr))
{
d2dContext->SetTarget(pBitmap);
d2dContext->BeginDraw();
d2dContext->Clear(D2D1::ColorF(D2D1::ColorF::Red)); // Clear the bitmap to Red
d2dContext->EndDraw();
// If I now use pBitmap to paint to the screen, I get a black rectange
// rather than the red one I was expecting
}
}
}
}
}
Note that I am fairly new to both DirectX and Metro style apps.
Thanks

Answer 1

what you're probably forgetting is that you dont draw your bitmap on your context.
what you can try is
hr = d2dContext->CreateBitmap(size, (const void *) 0, 0, &properties, &pBitmap);
if (SUCCEEDED(hr))
{
ID2D1Image *pImage = nullptr;
d2dContext->GetTarget(&image);
d2dContext->SetTarget(pBitmap);
d2dContext->BeginDraw();
d2dContext->Clear(D2D1::ColorF(D2D1::ColorF::Red)); // Clear the bitmap to Red
d2dContext->SetTarget(pImage);
d2dContext->DrawBitmap(pBitmap);
d2dContext->EndDraw();
}
what you do is store your rendertarget and then draw your bitmap and at the end you set your context to the right render target and let it draw your bitmap on it