This will enable an engine to run on the secondary monitor of a dual monitor system by adding -monitor2 to the command line. What this actually does is switch the primary monitor to the secondary in Vid_Init and restore it back in Vid_Shutdown (which is called by Host_Error). So this is achieves dual monitor support for a client by cheating a little, but it isn't much different than how Quake sets everything to fullscreen and resets it back on shutdown/exit. Reason: Windows and OpenGL on dual monitors may or may not have hardware acceleration on the 2nd monitor. This method works around the issue.
Instructions
1. In the beginning of Vid_Init do something like this (in gl_vidnt.c or vid_wgl.c depending on your engine):
Code: Select all
if (COM_CheckParm("-monitor2"))
{
CollectMonitorInformation ();
if (num_monitors == 2) // This is written in a 2-monitor way, don't have a third monitor to test triple monitor
SwapPrimaryMonitor (); // Set monitors_swapped to 1
}Code: Select all
if (monitors_swapped)
RestorePrimaryMonitor ();Code: Select all
#define POINTER_64 __ptr64 //Baker
#include "quakedef.h" // Almost optional!
#include <windows.h>
#define MSGBOX(x) MessageBox(NULL, x, "Info", MB_OK); // Developer message
typedef struct
{
char DeviceName[32]; // wingdi.h --> CCHFORMNAME which is 32
int original_x;
int original_y;
int original_width;
int original_height;
} monitor_def_t;
#define MAX_NUM_MONITORS 2
monitor_def_t monitor_info[MAX_NUM_MONITORS];
int original_primary = -1;
int original_secondary = -1;
int num_monitors;
int monitors_swapped;
DISPLAY_DEVICE DisplayDevice;
char monitorstring[2048];
DEVMODE deviceMode[MAX_NUM_MONITORS];
void CollectMonitorInformation (void)
{
int i;
{
// Reset monitor info
num_monitors = 0; // Just in case
original_primary = -1; // Just in case
ZeroMemory(&DisplayDevice, sizeof(DISPLAY_DEVICE));
DisplayDevice.cb = sizeof(DisplayDevice);
}
for(i = 0; EnumDisplayDevices(NULL, i, &DisplayDevice, 0) && num_monitors < MAX_NUM_MONITORS; i++)
{
if(DisplayDevice.StateFlags & DISPLAY_DEVICE_MIRRORING_DRIVER || !(DisplayDevice.StateFlags & DISPLAY_DEVICE_ATTACHED_TO_DESKTOP))
continue; // Non-monitor
// Ok we found a monitor
deviceMode[num_monitors].dmSize = sizeof(DEVMODE);
deviceMode[num_monitors].dmFields = DM_PELSWIDTH | DM_PELSHEIGHT | DM_BITSPERPEL | DM_POSITION | DM_DISPLAYFREQUENCY | DM_DISPLAYFLAGS;
EnumDisplaySettings(DisplayDevice.DeviceName, ENUM_CURRENT_SETTINGS, &deviceMode[num_monitors]);
// Populate fields
strcpy (monitor_info[num_monitors].DeviceName, DisplayDevice.DeviceName);
monitor_info[num_monitors].original_x = deviceMode[num_monitors].dmPosition.x;
monitor_info[num_monitors].original_y = deviceMode[num_monitors].dmPosition.y;
monitor_info[num_monitors].original_width = deviceMode[num_monitors].dmPelsWidth;
monitor_info[num_monitors].original_height = deviceMode[num_monitors].dmPelsHeight;
if (deviceMode[num_monitors].dmPosition.x == 0 && deviceMode[num_monitors].dmPosition.y ==0)
original_primary = num_monitors; // Primary monitor is one with 0,0 xy position
else
original_secondary = num_monitors;
strcat (monitorstring, va("Monitor #%i %s %s x y w h %i %i %i %i\n",
num_monitors+1,
monitor_info[num_monitors].DeviceName,
num_monitors == original_primary ? "(Primary)" : num_monitors == original_secondary ? "(Secondary)" : "(Neither)",
monitor_info[num_monitors].original_x,
monitor_info[num_monitors].original_y,
monitor_info[num_monitors].original_width,
monitor_info[num_monitors].original_height));
num_monitors ++;
}
MSGBOX (va("Num monitors is %i", num_monitors));
MSGBOX (va("Monitor infos \n\n%s", monitorstring));
MSGBOX (va("Primary Monitor is %i and secondary is %i", original_primary, original_secondary));
}
void SetPrimaryMonitorOnDeviceName (const char *NewPrimaryMonitor, const char *NewSecondaryMonitor, int SecondaryX, int SecondaryY)
{
DEVMODE deviceMode_newSecondary;
DEVMODE deviceMode_newPrimary;
if (num_monitors == 0)
{
MSGBOX ("No monitors ... need to call CollectMonitorInformation first")
return;
}
MSGBOX (va("Setting monitor %s to primary monitor", NewPrimaryMonitor))
// Get primary infos
deviceMode_newPrimary.dmSize = sizeof(DEVMODE);
deviceMode_newPrimary.dmFields = DM_PELSWIDTH | DM_PELSHEIGHT | DM_BITSPERPEL | DM_POSITION | DM_DISPLAYFREQUENCY | DM_DISPLAYFLAGS;
EnumDisplaySettings(NewPrimaryMonitor, ENUM_CURRENT_SETTINGS, &deviceMode_newPrimary);
// Get secondary infos
deviceMode_newSecondary.dmSize = sizeof(DEVMODE);
deviceMode_newSecondary.dmFields = DM_PELSWIDTH | DM_PELSHEIGHT | DM_BITSPERPEL | DM_POSITION | DM_DISPLAYFREQUENCY | DM_DISPLAYFLAGS;
EnumDisplaySettings(NewSecondaryMonitor, ENUM_CURRENT_SETTINGS, &deviceMode_newSecondary);
// move old primary display to new position
deviceMode_newSecondary.dmFields = DM_POSITION;
deviceMode_newSecondary.dmPosition.x = deviceMode_newPrimary.dmPelsWidth;
deviceMode_newSecondary.dmPosition.y = 0;
ChangeDisplaySettingsEx(NewSecondaryMonitor, &deviceMode_newSecondary, NULL, CDS_UPDATEREGISTRY | CDS_NORESET, NULL);
// move old secondary display to 0,0
deviceMode_newPrimary.dmFields = DM_POSITION;
deviceMode_newPrimary.dmPosition.x = 0;
deviceMode_newPrimary.dmPosition.y = 0;
// CDS_UPDATEREGISTRY | CDS_NORESET = Have settings updated in registry, but CDS_NORESET means it won't take effect yet
ChangeDisplaySettingsEx(NewPrimaryMonitor, &deviceMode_newPrimary, NULL, CDS_SET_PRIMARY | CDS_UPDATEREGISTRY | CDS_NORESET , NULL);
ChangeDisplaySettingsEx (NULL, NULL, NULL, 0, NULL); // Force it to take effect
// Sleep (500); // Let it think a minute
}
void SwapPrimaryMonitor (void) // In a dual monitor situation, use 0 = first monitor or 1 = second monitor, etc.
{
// Set secondary monitor to primary
SetPrimaryMonitorOnDeviceName (monitor_info[original_secondary].DeviceName, monitor_info[original_primary].DeviceName, monitor_info[original_secondary].original_width, monitor_info[original_secondary].original_height);
monitors_swapped = 1;
}
void RestorePrimaryMonitor (void)
{
// Set original primary monitor back to primary
SetPrimaryMonitorOnDeviceName (monitor_info[original_primary].DeviceName, monitor_info[original_secondary].DeviceName, monitor_info[original_primary].original_width, monitor_info[original_primary].original_height);
monitors_swapped = 0;
}This code is only trivially locked to Quake. In fact, I think the above only uses va (...) from Quake. So it could actually be used in an Windows project pretty much unchanged.
There IS a way to do this "naturally" and just create a Window on the 2nd display, but since you will likely lose hardware acceleration I've found it isn't particularly useful (2 fps sucks). See thread ...
Inquisitive minds want to know ! And if they don't -- well like that ever has stopped me before ..