Method SetAlphaBitmap

Source/DX9VideoProcessor.cpp:3217–3273

// IMFVideoMixerBitmap

STDMETHODIMP CDX9VideoProcessor::SetAlphaBitmap(const MFVideoAlphaBitmap *pBmpParms)
{
	CheckPointer(pBmpParms, E_POINTER);
	CAutoLock cRendererLock(&m_pFilter->m_RendererLock);

	CheckPointer(m_pD3DDevEx, E_ABORT);
	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_pD3DDevEx, D3DFMT_A8R8G8B8, bm.bmWidth, bm.bmHeight, D3DUSAGE_DYNAMIC);
		if (S_OK == hr) {
			D3DLOCKED_RECT lr;
			hr = m_TexAlphaBitmap.pSurface->LockRect(&lr, nullptr, D3DLOCK_DISCARD);
			if (S_OK == hr) {
				if (bm.bmWidthBytes == lr.Pitch) {
					memcpy(lr.pBits, bm.bmBits, bm.bmWidthBytes * bm.bmHeight);
				} else {
					LONG linesize = std::min<LONG>(bm.bmWidthBytes, lr.Pitch);
					BYTE* src = (BYTE*)bm.bmBits;
					BYTE* dst = (BYTE*)lr.pBits;
					for (LONG y = 0; y < bm.bmHeight; ++y) {
						memcpy(dst, src, linesize);
						src += bm.bmWidthBytes;
						dst += lr.Pitch;
					}
				}
				hr = m_TexAlphaBitmap.pSurface->UnlockRect();
			}
		}
	} else {
		return E_INVALIDARG;
	}

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

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

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

	return hr;
}