Method SetAlphaBitmap

Source/DX11VideoProcessor.cpp:4541–4583

// IMFVideoMixerBitmap

STDMETHODIMP CDX11VideoProcessor::SetAlphaBitmap(const MFVideoAlphaBitmap *pBmpParms)
{
	CheckPointer(pBmpParms, E_POINTER);
	CAutoLock cRendererLock(&m_pFilter->m_RendererLock);

	HRESULT hr = S_FALSE;

	if (pBmpParms->GetBitmapFromDC && pBmpParms->bitmap.hdc) {
		HBITMAP hBitmap = (HBITMAP)GetCurrentObject(pBmpParms->bitmap.hdc, OBJ_BITMAP);
		if (!hBitmap) {
			return E_INVALIDARG;
		}
		DIBSECTION info = {0};
		if (!::GetObjectW(hBitmap, sizeof(DIBSECTION), &info)) {
			return E_INVALIDARG;
		}
		BITMAP& bm = info.dsBm;
		if (!bm.bmWidth || !bm.bmHeight || bm.bmBitsPixel != 32 || !bm.bmBits) {
			return E_INVALIDARG;
		}

		hr = m_TexAlphaBitmap.CheckCreate(m_pDevice, DXGI_FORMAT_B8G8R8A8_UNORM, bm.bmWidth, bm.bmHeight, Tex2D_DefaultShader);
		DLogIf(FAILED(hr), L"CDX11VideoProcessor::SetAlphaBitmap() : CheckCreate() failed with error {}", HR2Str(hr));
		if (S_OK == hr) {
			m_pDeviceContext->UpdateSubresource(m_TexAlphaBitmap.pTexture, 0, nullptr, bm.bmBits, bm.bmWidthBytes, 0);
		}
	} else {
		return E_INVALIDARG;
	}

	m_bAlphaBitmapEnable = SUCCEEDED(hr) && m_TexAlphaBitmap.pShaderResource;

	if (m_bAlphaBitmapEnable) {
		m_AlphaBitmapRectSrc = { 0, 0, (LONG)m_TexAlphaBitmap.desc.Width, (LONG)m_TexAlphaBitmap.desc.Height };
		m_AlphaBitmapNRectDest = { 0, 0, 1, 1 };

		m_pAlphaBitmapVertex.Release();

		hr = UpdateAlphaBitmapParameters(&pBmpParms->params);
	}

	return hr;
}

STDMETHODIMP CDX11VideoProcessor::UpdateAlphaBitmapParameters(const MFVideoAlphaBitmapParams *pBmpParms)
{