winamp/Src/Winamp/VideoOutputChildDDraw.cpp

#include "main.h"
#include "VideoOutputChildDDraw.h"
#include <ddraw.h>

class MonitorFinder
{
public:
	MonitorFinder(HMONITOR hm) : m_monitor_to_find(hm), m_found_devguid(0)
	{}

	HMONITOR m_monitor_to_find;
	int m_found_devguid;
	GUID m_devguid;
};

static BOOL WINAPI DDEnumCallbackEx(GUID FAR *lpGUID, LPSTR lpDriverDescription, LPSTR lpDriverName, LPVOID lpContext, HMONITOR hm)
{
	MonitorFinder *ovo = (MonitorFinder *)lpContext;
	if (ovo->m_found_devguid) return 1;
	if (hm == ovo->m_monitor_to_find)
	{
		ovo->m_devguid = *lpGUID;
		ovo->m_found_devguid = 1;
	}
	return 1;
}

void VideoOutputChildDDraw::update_monitor_coords()
{
	//find the correct monitor if multiple monitor support is present
	m_mon_x = 0;
	m_mon_y = 0;

	HMONITOR hm = MonitorFromWindow(parent, 0);
	if (hm)
	{
		HINSTANCE hdd = LoadLibraryW(TEXT("ddraw.dll"));
		if (hdd)
		{
			typedef BOOL (FAR PASCAL * LPDDENUMCALLBACKEXA)(GUID FAR *, LPSTR, LPSTR, LPVOID, HMONITOR);
			typedef HRESULT (WINAPI * LPDIRECTDRAWENUMERATEEX)( LPDDENUMCALLBACKEXA lpCallback, LPVOID lpContext, DWORD dwFlags);
			LPDIRECTDRAWENUMERATEEX lpDDEnumEx;
			lpDDEnumEx = (LPDIRECTDRAWENUMERATEEX) GetProcAddress(hdd, "DirectDrawEnumerateExW");
			if (lpDDEnumEx)
			{
				MonitorFinder finder(hm);

				lpDDEnumEx(&DDEnumCallbackEx, &finder, DDENUM_ATTACHEDSECONDARYDEVICES | DDENUM_NONDISPLAYDEVICES);
				foundGUID=!!finder.m_found_devguid;
				if (foundGUID)
				{
					m_devguid=finder.m_devguid;
					MONITORINFOEXW mi;
					memset(&mi, 0, sizeof(mi));
					mi.cbSize = sizeof(mi);
					if (GetMonitorInfoA(hm, &mi))
					{
						m_mon_x = mi.rcMonitor.left;
						m_mon_y = mi.rcMonitor.top;
					}
				}
			}
			FreeLibrary(hdd);
		}
	}	
}