libobs-d3d11: Store index and add "Start" function

This allows restarting the duplicator at a later point in time.

libobs-d3d11/d3d11-duplicator.cpp

@@ -33,14 +33,13 @@ static inline bool get_monitor(gs_device_t *device, int monitor_idx,
 	return true;
 }
 
-gs_duplicator::gs_duplicator(gs_device_t *device_, int monitor_idx)
-	: texture(nullptr), device(device_)
+void gs_duplicator::Start()
 {
 	ComPtr<IDXGIOutput1> output1;
 	ComPtr<IDXGIOutput> output;
 	HRESULT hr;
 
-	if (!get_monitor(device, monitor_idx, output.Assign()))
+	if (!get_monitor(device, idx, output.Assign()))
 		throw "Invalid monitor index";
 
 	hr = output->QueryInterface(__uuidof(IDXGIOutput1),
@@ -53,6 +52,12 @@ gs_duplicator::gs_duplicator(gs_device_t *device_, int monitor_idx)
 		throw HRError("Failed to duplicate output", hr);
 }
 
+gs_duplicator::gs_duplicator(gs_device_t *device_, int monitor_idx)
+	: texture(nullptr), device(device_), idx(monitor_idx)
+{
+	Start();
+}
+
 gs_duplicator::~gs_duplicator()
 {
 	delete texture;

libobs-d3d11/d3d11-subsystem.hpp

@@ -453,6 +453,9 @@ struct gs_duplicator {
 	ComPtr<IDXGIOutputDuplication> duplicator;
 	gs_texture_2d *texture;
 	gs_device_t *device;
+	int idx;
+
+	void Start();
 
 	gs_duplicator(gs_device_t *device, int monitor_idx);
 	~gs_duplicator();