Sample Code - DirectX 11 : Get Image Data(Byte array) from ID3D11ShaderResourceView

[C++] DirectX 11 : Get Image Data(Byte array) from ID3D11ShaderResourceView
BYTE* GetImageData(ID3D11Device* device, ID3D11DeviceContext* context, ID3D11ShaderResourceView* shaderResourceView, /*OUT*/ int* nWidth, /*OUT*/ int*  nHeight)
{
	ID3D11Resource* resource = NULL;;
	D3D11_SHADER_RESOURCE_VIEW_DESC srvDesc;

	if (shaderResourceView)
	{
		shaderResourceView->GetResource(&resource);
		shaderResourceView->GetDesc(&srvDesc);
	}
	else
		return NULL;

	ID3D11Texture2D* tex = (ID3D11Texture2D*)resource;
	if (tex)
	{
		D3D11_TEXTURE2D_DESC description;
		tex->GetDesc(&description);
		description.BindFlags = 0;
		description.CPUAccessFlags = D3D11_CPU_ACCESS_READ | D3D11_CPU_ACCESS_WRITE;
		description.Usage = D3D11_USAGE_STAGING;

		ID3D11Texture2D* texTemp = NULL;

		HRESULT hr = device->CreateTexture2D(&description, NULL, &texTemp);
		if (FAILED(hr))
		{
			if (texTemp)
			{
				texTemp->Release();
				texTemp = NULL;
			}
			return NULL;
		}
		context->CopyResource(texTemp, tex);

		D3D11_MAPPED_SUBRESOURCE  mapped;
		unsigned int subresource = 0
		hr = context->Map(texTemp, 0, D3D11_MAP_READ, 0, &mapped);
		if (FAILED(hr))
		{
			texTemp->Release();
			texTemp = NULL;
			return NULL;
		}

		*nWidth = description.Width;
		*nHeight = description.Height;
		const int pitch = mapped.RowPitch;
		BYTE* source = (BYTE*)(mapped.pData);
		BYTE* dest = new BYTE[(*nWidth)*(*nHeight) * 4];
		BYTE* destTemp = dest;
		for (int i = 0; i < *nHeight; ++i)
		{
			memcpy(destTemp, source, *nWidth * 4);
			source += pitch;
			destTemp += *nWidth * 4;
		}
		context->Unmap(texTemp, 0);
		return dest;
	}
	else
		return NULL;
}