JoinSwapGroupNV

Hello Friends,
I am not very good at programming, basically i am using openGL on two separate machines (code is written below), each openGL window contains left/right images. I want to synchronize left/right images of first window on first machine with the left/right images on second window of the second machine, I know JoinSwapGroupNV command can do it but don’t know how i can write a code for this command. can anyone please help me to write a code of JoinSwapGroupNV that can fit into mine code. please…

-------------------CODE--------------------
#include “stdafx.h” // RB needs this here

#include <windows.h> // Header File For Windows
#include <gl\gl.h> // Header File For The OpenGL32 Library
#include <gl\glu.h> // Header File For The GLu32 Library

HDC hDC=NULL; // Private GDI Device Context
HGLRC hRC=NULL; // Permanent Rendering Context
HWND hWnd=NULL; // Holds Our Window Handle
HINSTANCE hInstance; // Holds The Instance Of The Application

bool keys[256]; // Array Used For The Keyboard Routine
bool active=TRUE; // Window Active Flag Set To TRUE By Default
bool fullscreen=TRUE; // Fullscreen Flag Set To Fullscreen Mode By Default

bool LEye=TRUE; //RB flag showing that left eye frame is showing

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM); // Declaration For WndProc

GLvoid ReSizeGLScene(GLsizei width, GLsizei height) // Resize And Initialize The GL Window
{
if (height==0) // Prevent A Divide By Zero By
{
height=1; // Making Height Equal One
}

glViewport(0,0,width,height);						// Reset The Current Viewport

glMatrixMode(GL_PROJECTION);						// Select The Projection Matrix
glLoadIdentity();									// Reset The Projection Matrix

// Calculate The Aspect Ratio Of The Window
gluPerspective(45.0f,(GLfloat)width/(GLfloat)height,0.1f,100.0f);

glMatrixMode(GL_MODELVIEW);							// Select The Modelview Matrix
glLoadIdentity();									// Reset The Modelview Matrix

}

int InitGL(GLvoid) // All Setup For OpenGL Goes Here
{
glShadeModel(GL_SMOOTH); // Enable Smooth Shading
glClearColor(0.0f, 0.0f, 0.0f, 0.5f); // Black Background
glClearDepth(1.0f); // Depth Buffer Setup
glEnable(GL_DEPTH_TEST); // Enables Depth Testing
glDepthFunc(GL_LEQUAL); // The Type Of Depth Testing To Do
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); // Really Nice Perspective Calculations
return TRUE; // Initialization Went OK
}

int DrawGLScene(GLvoid) // Here’s Where We Do All The Drawing
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear Screen And Depth Buffer
glLoadIdentity(); // Reset The Current Modelview Matrix

//glTranslatef(-1.5f,0.0f,-6.5f);						// Move Left 1.5 Units And Into The Screen 6.0

if (LEye)
{
    glTranslatef(-5.0f,0.0f,-4.0f);						// 
	glBegin(GL_QUADS);									// Draw A Quad
	    glColor3f(1.0f,1.0f,1.0f);                     //White Color
		glVertex3f(-1.0f, 1.0f, 0.0f);					// Top Left
		glVertex3f( 1.0f, 1.0f, 0.0f);					// Top Right
		glVertex3f( 1.0f,-1.0f, 0.0f);					// Bottom Right
		glVertex3f(-1.0f,-1.0f, 0.0f);					// Bottom Left
	glEnd();
	glTranslatef(7.0f,0.0f,1.8f);	
	glBegin(GL_QUADS);									// Draw A Quad
	    glColor3f(1.0f,0.0f,0.0f);                     //Red Color
		glVertex3f(-1.0f, 1.0f, 0.0f);					// Top Left
    	glVertex3f( 1.0f, 1.0f, 0.0f);					// Top Right
		glVertex3f( 1.0f,-1.0f, 0.0f);					// Bottom Right
		glVertex3f(-1.0f,-1.0f, 0.0f);					// Bottom Left
	glEnd();
    LEye = FALSE;
}
else
{

	glTranslatef(-2.7f,0.0f,-4.0f);						//
	glBegin(GL_QUADS);									// Draw A Quad
	    glColor3f(1.0f,1.0f,1.0f);                      //White Color
		glVertex3f(-1.0f, 1.0f, 0.0f);					// Top Left
		glVertex3f( 1.0f, 1.0f, 0.0f);					// Top Right
		glVertex3f( 1.0f,-1.0f, 0.0f);					// Bottom Right
		glVertex3f(-1.0f,-1.0f, 0.0f);					// Bottom Left
	glEnd();
	glTranslatef(4.7f,0.0f,1.8f);
    glBegin(GL_QUADS);									// Draw A Quad
	    glColor3f(0.0f,1.0f,0.0f);                      //Green Color
		glVertex3f(-1.0f, 1.0f, 0.0f);					// Top Left
		glVertex3f( 1.0f, 1.0f, 0.0f);					// Top Right
		glVertex3f( 1.0f,-1.0f, 0.0f);					// Bottom Right
		glVertex3f(-1.0f,-1.0f, 0.0f);					// Bottom Left
	glEnd();
	LEye = TRUE;
}
	return TRUE;										// Keep Going

}

GLvoid KillGLWindow(GLvoid) // Properly Kill The Window
{
if (fullscreen) // Are We In Fullscreen Mode?
{
ChangeDisplaySettings(NULL,0); // If So Switch Back To The Desktop
ShowCursor(TRUE); // Show Mouse Pointer
}

if (hRC)											// Do We Have A Rendering Context?
{
	if (!wglMakeCurrent(NULL,NULL))					// Are We Able To Release The DC And RC Contexts?
	{
		MessageBox(NULL,"Release Of DC And RC Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
	}

	if (!wglDeleteContext(hRC))						// Are We Able To Delete The RC?
	{
		MessageBox(NULL,"Release Rendering Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
	}
	hRC=NULL;										// Set RC To NULL
}

if (hDC && !ReleaseDC(hWnd,hDC))					// Are We Able To Release The DC
{
	MessageBox(NULL,"Release Device Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
	hDC=NULL;										// Set DC To NULL
}

if (hWnd && !DestroyWindow(hWnd))					// Are We Able To Destroy The Window?
{
	MessageBox(NULL,"Could Not Release hWnd.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
	hWnd=NULL;										// Set hWnd To NULL
}

if (!UnregisterClass("OpenGL",hInstance))			// Are We Able To Unregister Class
{
	MessageBox(NULL,"Could Not Unregister Class.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
	hInstance=NULL;									// Set hInstance To NULL
}

}

/* This Code Creates Our OpenGL Window. Parameters Are: *

  • title - Title To Appear At The Top Of The Window *
  • width - Width Of The GL Window Or Fullscreen Mode *
  • height - Height Of The GL Window Or Fullscreen Mode *
  • bits - Number Of Bits To Use For Color (8/16/24/32) *
  • fullscreenflag - Use Fullscreen Mode (TRUE) Or Windowed Mode (FALSE) */

BOOL CreateGLWindow(char* title, int width, int height, int bits, bool fullscreenflag)
{
GLuint PixelFormat; // Holds The Results After Searching For A Match
WNDCLASS wc; // Windows Class Structure
DWORD dwExStyle; // Window Extended Style
DWORD dwStyle; // Window Style
RECT WindowRect; // Grabs Rectangle Upper Left / Lower Right Values
WindowRect.left=(long)0; // Set Left Value To 0
WindowRect.right=(long)width; // Set Right Value To Requested Width
WindowRect.top=(long)0; // Set Top Value To 0
WindowRect.bottom=(long)height; // Set Bottom Value To Requested Height

fullscreen=fullscreenflag;			// Set The Global Fullscreen Flag

hInstance			= GetModuleHandle(NULL);				// Grab An Instance For Our Window
wc.style			= CS_HREDRAW | CS_VREDRAW | CS_OWNDC;	// Redraw On Size, And Own DC For Window.
wc.lpfnWndProc		= (WNDPROC) WndProc;					// WndProc Handles Messages
wc.cbClsExtra		= 0;									// No Extra Window Data
wc.cbWndExtra		= 0;									// No Extra Window Data
wc.hInstance		= hInstance;							// Set The Instance
wc.hIcon			= LoadIcon(NULL, IDI_WINLOGO);			// Load The Default Icon
wc.hCursor			= LoadCursor(NULL, IDC_ARROW);			// Load The Arrow Pointer
wc.hbrBackground	= NULL;									// No Background Required For GL
wc.lpszMenuName		= NULL;									// We Don't Want A Menu
wc.lpszClassName	= "OpenGL";								// Set The Class Name

if (!RegisterClass(&wc))									// Attempt To Register The Window Class
{
	MessageBox(NULL,"Failed To Register The Window Class.","ERROR",MB_OK|MB_ICONEXCLAMATION);
	return FALSE;											// Return FALSE
}

if (fullscreen)												// Attempt Fullscreen Mode?
{
	DEVMODE dmScreenSettings;								// Device Mode
	memset(&dmScreenSettings,0,sizeof(dmScreenSettings));	// Makes Sure Memory's Cleared
	dmScreenSettings.dmSize=sizeof(dmScreenSettings);		// Size Of The Devmode Structure
	dmScreenSettings.dmPelsWidth	= width;				// Selected Screen Width
	dmScreenSettings.dmPelsHeight	= height;				// Selected Screen Height
	dmScreenSettings.dmBitsPerPel	= bits;					// Selected Bits Per Pixel
	dmScreenSettings.dmFields=DM_BITSPERPEL|DM_PELSWIDTH|DM_PELSHEIGHT;

	// Try To Set Selected Mode And Get Results.  NOTE: CDS_FULLSCREEN Gets Rid Of Start Bar.
	if (ChangeDisplaySettings(&dmScreenSettings,CDS_FULLSCREEN)!=DISP_CHANGE_SUCCESSFUL)
	{
		// If The Mode Fails, Offer Two Options.  Quit Or Use Windowed Mode.
		if (MessageBox(NULL,"The Requested Fullscreen Mode Is Not Supported By

Your Video Card. Use Windowed Mode Instead?",“NeHe GL”,MB_YESNO|MB_ICONEXCLAMATION)==IDYES)
{
fullscreen=FALSE; // Windowed Mode Selected. Fullscreen = FALSE
}
else
{
// Pop Up A Message Box Letting User Know The Program Is Closing.
MessageBox(NULL,“Program Will Now Close.”,“ERROR”,MB_OK|MB_ICONSTOP);
return FALSE; // Return FALSE
}
}
}

if (fullscreen)												// Are We Still In Fullscreen Mode?
{
	dwExStyle=WS_EX_APPWINDOW;								// Window Extended Style
	dwStyle=WS_POPUP;										// Windows Style
	ShowCursor(FALSE);										// Hide Mouse Pointer
}
else
{
	dwExStyle=WS_EX_APPWINDOW | WS_EX_WINDOWEDGE;			// Window Extended Style
	dwStyle=WS_OVERLAPPEDWINDOW;							// Windows Style
}

AdjustWindowRectEx(&WindowRect, dwStyle, FALSE, dwExStyle);		// Adjust Window To True Requested Size

// Create The Window
if (!(hWnd=CreateWindowEx(	dwExStyle,							// Extended Style For The Window
							"OpenGL",							// Class Name
							title,								// Window Title
							dwStyle |							// Defined Window Style
							WS_CLIPSIBLINGS |					// Required Window Style
							WS_CLIPCHILDREN,					// Required Window Style
							0, 0,								// Window Position
							WindowRect.right-WindowRect.left,	// Calculate Window Width
							WindowRect.bottom-WindowRect.top,	// Calculate Window Height
							NULL,								// No Parent Window
							NULL,								// No Menu
							hInstance,							// Instance
							NULL)))								// Dont Pass Anything To WM_CREATE
{
	KillGLWindow();								// Reset The Display
	MessageBox(NULL,"Window Creation Error.","ERROR",MB_OK|MB_ICONEXCLAMATION);
	return FALSE;								// Return FALSE
}

static	PIXELFORMATDESCRIPTOR pfd=				// pfd Tells Windows How We Want Things To Be
{
	sizeof(PIXELFORMATDESCRIPTOR),				// Size Of This Pixel Format Descriptor
	1,											// Version Number
	PFD_DRAW_TO_WINDOW |						// Format Must Support Window
	PFD_SUPPORT_OPENGL |						// Format Must Support OpenGL
	PFD_DOUBLEBUFFER,							// Must Support Double Buffering
	PFD_TYPE_RGBA,								// Request An RGBA Format
	bits,										// Select Our Color Depth
	0, 0, 0, 0, 0, 0,							// Color Bits Ignored
	0,											// No Alpha Buffer
	0,											// Shift Bit Ignored
	0,											// No Accumulation Buffer
	0, 0, 0, 0,									// Accumulation Bits Ignored
	16,											// 16Bit Z-Buffer (Depth Buffer)  
	0,											// No Stencil Buffer
	0,											// No Auxiliary Buffer
	PFD_MAIN_PLANE,								// Main Drawing Layer
	0,											// Reserved
	0, 0, 0										// Layer Masks Ignored
};

if (!(hDC=GetDC(hWnd)))							// Did We Get A Device Context?
{
	KillGLWindow();								// Reset The Display
	MessageBox(NULL,"Can't Create A GL Device Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
	return FALSE;								// Return FALSE
}

if (!(PixelFormat=ChoosePixelFormat(hDC,&pfd)))	// Did Windows Find A Matching Pixel Format?
{
	KillGLWindow();								// Reset The Display
	MessageBox(NULL,"Can't Find A Suitable PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);
	return FALSE;								// Return FALSE
}

if(!SetPixelFormat(hDC,PixelFormat,&pfd))		// Are We Able To Set The Pixel Format?
{
	KillGLWindow();								// Reset The Display
	MessageBox(NULL,"Can't Set The PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);
	return FALSE;								// Return FALSE
}

if (!(hRC=wglCreateContext(hDC)))				// Are We Able To Get A Rendering Context?
{
	KillGLWindow();								// Reset The Display
	MessageBox(NULL,"Can't Create A GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
	return FALSE;								// Return FALSE
}

if(!wglMakeCurrent(hDC,hRC))					// Try To Activate The Rendering Context
{
	KillGLWindow();								// Reset The Display
	MessageBox(NULL,"Can't Activate The GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
	return FALSE;								// Return FALSE
}

ShowWindow(hWnd,SW_SHOW);						// Show The Window
SetForegroundWindow(hWnd);						// Slightly Higher Priority
SetFocus(hWnd);									// Sets Keyboard Focus To The Window
ReSizeGLScene(width, height);					// Set Up Our Perspective GL Screen

if (!InitGL())									// Initialize Our Newly Created GL Window
{
	KillGLWindow();								// Reset The Display
	MessageBox(NULL,"Initialization Failed.","ERROR",MB_OK|MB_ICONEXCLAMATION);
	return FALSE;								// Return FALSE
}

return TRUE;									// Success

}

LRESULT CALLBACK WndProc( HWND hWnd, // Handle For This Window
UINT uMsg, // Message For This Window
WPARAM wParam, // Additional Message Information
LPARAM lParam) // Additional Message Information
{
switch (uMsg) // Check For Windows Messages
{
case WM_ACTIVATE: // Watch For Window Activate Message
{
if (!HIWORD(wParam)) // Check Minimization State
{
active=TRUE; // Program Is Active
}
else
{
active=FALSE; // Program Is No Longer Active
}

		return 0;								// Return To The Message Loop
	}

	case WM_SYSCOMMAND:
	{
		switch (wParam)
		{
			case SC_SCREENSAVE:
			case SC_MONITORPOWER:
				return 0;
		}
		break;
	}

	case WM_CLOSE:								// Did We Receive A Close Message?
	{
		PostQuitMessage(0);						// Send A Quit Message
		return 0;								// Jump Back
	}

	case WM_KEYDOWN:							// Is A Key Being Held Down?
	{
		keys[wParam] = TRUE;					// If So, Mark It As TRUE
		return 0;								// Jump Back
	}

	case WM_KEYUP:								// Has A Key Been Released?
	{
		keys[wParam] = FALSE;					// If So, Mark It As FALSE
		return 0;								// Jump Back
	}

	case WM_SIZE:								// Resize The OpenGL Window
	{
		ReSizeGLScene(LOWORD(lParam),HIWORD(lParam));  // LoWord=Width, HiWord=Height
		return 0;								// Jump Back
	}
}

// Pass All Unhandled Messages To DefWindowProc
return DefWindowProc(hWnd,uMsg,wParam,lParam);

}

int WINAPI WinMain( HINSTANCE hInstance, // Instance
HINSTANCE hPrevInstance, // Previous Instance
LPSTR lpCmdLine, // Command Line Parameters
int nCmdShow) // Window Show State
{
MSG msg; // Windows Message Structure
BOOL done=FALSE; // Bool Variable To Exit Loop

// Ask The User Which Screen Mode They Prefer
if (MessageBox(NULL,"Would You Like To Run In Fullscreen Mode?", "Start FullScreen?",MB_YESNO|MB_ICONQUESTION)==IDNO)
{
	fullscreen=FALSE;							// Windowed Mode
}

// Create Our OpenGL Window
if (!CreateGLWindow("OpenGL2",2540,640,16,fullscreen))
{

	return 0;									// Quit If Window Was Not Created
}

while(!done)									// Loop That Runs While done=FALSE
{
	if (PeekMessage(&msg,NULL,0,0,PM_REMOVE))	// Is There A Message Waiting?
	{
		if (msg.message==WM_QUIT)				// Have We Received A Quit Message?
		{
			done=TRUE;							// If So done=TRUE
		}
		else									// If Not, Deal With Window Messages
		{
			TranslateMessage(&msg);				// Translate The Message
			DispatchMessage(&msg);				// Dispatch The Message
		}
	}
	else										// If There Are No Messages
	{
		// Draw The Scene.  Watch For ESC Key And Quit Messages From DrawGLScene()
		if ((active && !DrawGLScene()) || keys[VK_ESCAPE])	// Active?  Was There A Quit Received?
		{
			done=TRUE;							// ESC or DrawGLScene Signalled A Quit
		}
		else									// Not Time To Quit, Update Screen
		{
			SwapBuffers(hDC);					// Swap Buffers (Double Buffering)
		}

		if (keys[VK_F1])						// Is F1 Being Pressed?
		{
			keys[VK_F1]=FALSE;					// If So Make Key FALSE
			KillGLWindow();						// Kill Our Current Window
			fullscreen=!fullscreen;				// Toggle Fullscreen / Windowed Mode
			// Recreate Our OpenGL Window
			if (!CreateGLWindow("OpenGL2",640,480,16,fullscreen))
			{
				return 0;						// Quit If Window Was Not Created
			}
		}
	}
}

// Shutdown
KillGLWindow();									// Kill The Window
return (msg.wParam);							// Exit The Program

}

Do you have gen-locked nvidia quadro-cards synced up between the two machines? Otherwise this won’t work… just asking to make sure :slight_smile: Also, this won’t actually get you the same frame on both machines, only align the vsync - you need to sync the machines up using some other method (e.g. network or telepathy :slight_smile: )

Hello Mikkel, Thanks for your reply.
actually i am using one Nvidia FX4600 (two DVI ports)which can support two machines’s running at 120Hz at same time (120Hz projector and 120Hz SamsungLCD) & GSync card. they are almost in sync but after 4-5 minutes they start getting out of sync and comeback again in 2-3 minutes, I was thinking might be using JoinSwapGroupNV function i can lock left/right images on both projector and LCD together (both projector and LCD are using their own windows to present left/right images)…what is your opinion… how can i solve this 4-5 minutes drift problem…please help

If both the outputs are at the exact same res and rate (same modeline), and you enable twinview, then they should be the same.

That means you should treat it as one screen and draw on the left and right half.

Works fine. If your modelines aren’t the same, then maybe G-Sync would help, but I’d expect it to just control one output, so I doubt.

Bruce

Bruce

Hello Bruce, Thanks
both are running at same refresh rate of 119.997hz but their resolutions are not same, DepthQ projector resolution in 1280x729 and SamsungLCD resolution is 1680x1050. they get sync for about 45 minutes but start drifting after that,…as you mentioned (That means you should treat it as one screen and draw on the left and right half.)I am using the same…isn’t their any way i can solve this problem.

you mentioned about G-Sync…how it can solve this problem… i am using one Nvidia G-Sync & one QuadroFX 4600 card for both projector and LCD…how i can use G-Sync for this…please help

I think the swap is probably in sync, since it’s twinview. The problem is probably the read-out to the actual DVI. I presume it jumps one whole frame out after a while? Or does the actual sync drift away? You would have to put a scope onto the analog vertical sync to tell.

So, when I considered this problem cropping up, I anticipated trying to tweak the modelines to get the pixel clocks as close as possible, probably by padding total h & v pixels (essentially adding more blank pixels after each line or frame).

What G-Sync does is lock the vertical refresh of the output to the v-sync of the genlock signal. When you use FrameLock, you can swap in sync too. So G-Sync is essentially slewing the refresh to match the external. Possibly, when engaged, it slews both outputs - not sure. You’d have to try.

If you aren’t using FrameLock (the software side of G-sync) as well as genlock, you should try that - possibly when one output slips out, Framelock will be able to tell and let you fix it.

Don’t have a G-Sync card now, so I can’t really help with specifics.

Bruce

Thanks Bruce,
you are right, i think it is jumping whole frame out after a while.

could you please explain in more detail that how i can add more blank pixels after each line or frame??? any specific way of doing this…

Many Thanks

What about something like this :
http://www.nvidia.com/object/advanced_timings
The presentation is different on recent drivers, but I am pretty sure it is still possible to customize timings.
Then the display device might introduce its own problems.

That’s why you’re meant to do back porch - it ‘shouldn’t’ affect the visible image.

Look for softgenlock. They used to do it dynamically to analog outputs to match a hardware signal, but the theory is sound.

I was going to make new modelines in Linux.

Bruce