Direct2D Loading and Drawing Bitmap

Question

I'm trying to draw a bitmap to the screen; the code that calls to load the bitmap from a file works, but it seems the actual drawing part is causing some program crashes.

I followed a tutorial from MSDN, but the only change I made was instead of using ID2D1RenderTarget, I'm using a ID2D1DCRenderTarget.

Here's the Load method that works:

HRESULT LoadBitmapFromFile(
    ID2D1DCRenderTarget *pRenderTarget,
    IWICImagingFactory *pIWICFactory,
    PCWSTR uri,
    UINT destinationWidth,
    UINT destinationHeight,
    ID2D1Bitmap **ppBitmap
    )
{
    IWICBitmapDecoder *pDecoder = NULL;
    IWICBitmapFrameDecode *pSource = NULL;
    IWICStream *pStream = NULL;
    IWICFormatConverter *pConverter = NULL;
    IWICBitmapScaler *pScaler = NULL;
    HRESULT hr = pIWICFactory->CreateDecoderFromFilename(
        uri,
        NULL,
        GENERIC_READ,
        WICDecodeMetadataCacheOnLoad,
        &pDecoder
        );



    if (SUCCEEDED(hr))
    {
        // Create the initial frame.
        hr = pDecoder->GetFrame(0, &pSource);
    }
    if (SUCCEEDED(hr))
    {

        // Convert the image format to 32bppPBGRA
        // (DXGI_FORMAT_B8G8R8A8_UNORM + D2D1_ALPHA_MODE_PREMULTIPLIED).
        hr = pIWICFactory->CreateFormatConverter(&pConverter);

    }


    if (SUCCEEDED(hr))
    {
        // If a new width or height was specified, create an
        // IWICBitmapScaler and use it to resize the image.
        if (destinationWidth != 0 || destinationHeight != 0)
        {
            UINT originalWidth, originalHeight;
            hr = pSource->GetSize(&originalWidth, &originalHeight);
            if (SUCCEEDED(hr))
            {
                if (destinationWidth == 0)
                {
                    FLOAT scalar = static_cast<FLOAT>(destinationHeight) / static_cast<FLOAT>(originalHeight);
                    destinationWidth = static_cast<UINT>(scalar * static_cast<FLOAT>(originalWidth));
                }
                else if (destinationHeight == 0)
                {
                    FLOAT scalar = static_cast<FLOAT>(destinationWidth) / static_cast<FLOAT>(originalWidth);
                    destinationHeight = static_cast<UINT>(scalar * static_cast<FLOAT>(originalHeight));
                }

                hr = pIWICFactory->CreateBitmapScaler(&pScaler);
                if (SUCCEEDED(hr))
                {
                    hr = pScaler->Initialize(
                        pSource,
                        destinationWidth,
                        destinationHeight,
                        WICBitmapInterpolationModeCubic
                        );
                }
                if (SUCCEEDED(hr))
                {
                    hr = pConverter->Initialize(
                        pScaler,
                        GUID_WICPixelFormat32bppPBGRA,
                        WICBitmapDitherTypeNone,
                        NULL,
                        0.f,
                        WICBitmapPaletteTypeMedianCut
                        );
                }
            }
        }
        else // Don't scale the image.
        {
            hr = pConverter->Initialize(
                pSource,
                GUID_WICPixelFormat32bppPBGRA,
                WICBitmapDitherTypeNone,
                NULL,
                0.f,
                WICBitmapPaletteTypeMedianCut
                );
        }
    }
    if (SUCCEEDED(hr))
    {

        // Create a Direct2D bitmap from the WIC bitmap.
        hr = pRenderTarget->CreateBitmapFromWicBitmap(
            pConverter,
            NULL,
            ppBitmap
            );
    }

    if (pDecoder) pDecoder->Release();
    if (pSource) pSource->Release();
    if (pStream) pStream->Release();
    if (pScaler) pScaler->Release();

    return hr;
}

And in between the BeginDraw() and EndDraw() for the render target, I have the following code to draw the bitmap. This is the part that crashes the program when I attempt to run it:

d2dg->pRT->BeginDraw(); 

// Create a WIC Factory
HRESULT hr = CoCreateInstance(
CLSID_WICImagingFactory,
NULL,
CLSCTX_INPROC_SERVER,
IID_IWICImagingFactory,
(LPVOID*)&wicFactory);

hr = LoadBitmapFromFile(d2dg->pRT, wicFactory, L"image1.png", 400, 400, &pBitmap); 

D2D1_SIZE_F size = pBitmap->GetSize();
D2D1_POINT_2F upperLeftCorner = D2D1::Point2F(100.f, 10.f);
// Draw a bitmap.
d2dg->pRT->DrawBitmap(
    pBitmap,
    D2D1::RectF(
    upperLeftCorner.x,
    upperLeftCorner.y,
    upperLeftCorner.x + size.width,
    upperLeftCorner.y + size.height)
    );

d2dg->pRT->EndDraw();

Answer 1

Found the issue to this: the bitmap I wanted to draw was still NULL.

This can be fixed by deleting the ID2D1Bitmap **ppBitmap parameter from LoadBitmapFromFile and just work with the pointer to &pBitmap for any references to a bitmap within the method.

That way, pBitmap gets manipulated and will not remain NULL.