Fullscreen Vsync in Win32

SDL Development
1

I am using SDL1.2.11, WinXp, Ati X800 PCI Express videocard

I have tried setting the flags as follows:
flags = SDL_HWSURFACE | SDL_DOUBLEBUF | SDL_FULLSCREEN;
SDL_SetVideoMode(640, 480, 32, flags);
When rendering the screen, I call *SDL_Flip( ).

*However, vsync does not appear to be taking place as the frame rate
exceeds 60hz or
whatever I set the monitor refresh rate to.

Please advise!

2

Im not sure why vsync is off for you but if you’re in windows you can use
this function to turn on and off vsync:

#include <windows.h>

void VSyncOn(char On)
{
typedef void (APIENTRY * WGLSWAPINTERVALEXT) (int);

WGLSWAPINTERVALEXT wglSwapIntervalEXT = (WGLSWAPINTERVALEXT)
wglGetProcAddress(“wglSwapIntervalEXT”);
if (wglSwapIntervalEXT)
{
wglSwapIntervalEXT(On); // set vertical synchronisation
}
}> ----- Original Message -----

From: sdl-bounces+atrix2=cox.net@libsdl.org
[mailto:sdl-bounces+atrix2=cox.net at libsdl.org] On Behalf Of Adam Smith
Sent: Wednesday, July 05, 2006 7:26 PM
To: sdl at libsdl.org
Subject: [SDL] Fullscreen Vsync in Win32

I am using SDL1.2.11, WinXp, Ati X800 PCI Express videocard

I have tried setting the flags as follows:
*flags = SDL_HWSURFACE | SDL_DOUBLEBUF | SDL_FULLSCREEN;
SDL_SetVideoMode(640, 480, 32, flags);
*
When rendering the screen, I call *SDL_Flip( ).

*However, vsync does not appear to be taking place as the frame rate
exceeds 60hz or
whatever I set the monitor refresh rate to.

Please advise!

SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl

3

That technique works only when the SDL_OPENGL flag is set. You may have
to try forcing V-sync in the video card drivers, however that has never
worked outside of OpenGL in my experience [on a Geforce]. You can try
to use SDL_Delay to slow down the framerate.

Alan Wolfe wrote:> Im not sure why vsync is off for you but if you’re in windows you can use

this function to turn on and off vsync:

#include <windows.h>

void VSyncOn(char On)
{
typedef void (APIENTRY * WGLSWAPINTERVALEXT) (int);

WGLSWAPINTERVALEXT wglSwapIntervalEXT = (WGLSWAPINTERVALEXT)
wglGetProcAddress(“wglSwapIntervalEXT”);
if (wglSwapIntervalEXT)
{
wglSwapIntervalEXT(On); // set vertical synchronisation
}
}

-----Original Message-----
From: sdl-bounces+atrix2=cox.net at libsdl.org
[mailto:sdl-bounces+atrix2=cox.net at libsdl.org] On Behalf Of Adam Smith
Sent: Wednesday, July 05, 2006 7:26 PM
To: sdl at libsdl.org
Subject: [SDL] Fullscreen Vsync in Win32

I am using SDL1.2.11, WinXp, Ati X800 PCI Express videocard

I have tried setting the flags as follows:
*flags = SDL_HWSURFACE | SDL_DOUBLEBUF | SDL_FULLSCREEN;
SDL_SetVideoMode(640, 480, 32, flags);
*
When rendering the screen, I call *SDL_Flip( ).

*However, vsync does not appear to be taking place as the frame rate
exceeds 60hz or
whatever I set the monitor refresh rate to.

Please advise!

SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl

SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl

4

Adam Smith wrote:

I am using SDL1.2.11, WinXp, Ati X800 PCI Express videocard

I have tried setting the flags as follows:
*flags = SDL_HWSURFACE | SDL_DOUBLEBUF | SDL_FULLSCREEN;
SDL_SetVideoMode(640, 480, 32, flags);
*
When rendering the screen, I call *SDL_Flip( ).

*However, vsync does not appear to be taking place as the frame rate
exceeds 60hz or
whatever I set the monitor refresh rate to.

Please advise!

The ATI driver is probably set to force VSync off. It is usually on by
default however gamers think higher = better so they deliberately come
with VSync off.

Pete.

5

Thanks Damien, I didn’t know it only worked with the GL flag set> ----- Original Message -----

From: sdl-bounces+atrix2=cox.net@libsdl.org
[mailto:sdl-bounces+atrix2=cox.net at libsdl.org] On Behalf Of Damien A
Sent: Tuesday, July 25, 2006 6:48 PM
To: A list for developers using the SDL library. (includes SDL-announce)
Subject: Re: [SDL] Fullscreen Vsync in Win32

That technique works only when the SDL_OPENGL flag is set. You may have
to try forcing V-sync in the video card drivers, however that has never
worked outside of OpenGL in my experience [on a Geforce]. You can try
to use SDL_Delay to slow down the framerate.

Alan Wolfe wrote:

Im not sure why vsync is off for you but if you’re in windows you can use
this function to turn on and off vsync:

#include <windows.h>

void VSyncOn(char On)
{
typedef void (APIENTRY * WGLSWAPINTERVALEXT) (int);

WGLSWAPINTERVALEXT wglSwapIntervalEXT = (WGLSWAPINTERVALEXT)
wglGetProcAddress(“wglSwapIntervalEXT”);
if (wglSwapIntervalEXT)
{
wglSwapIntervalEXT(On); // set vertical synchronisation
}
}

-----Original Message-----
From: sdl-bounces+atrix2=cox.net at libsdl.org
[mailto:sdl-bounces+atrix2=cox.net at libsdl.org] On Behalf Of Adam Smith
Sent: Wednesday, July 05, 2006 7:26 PM
To: sdl at libsdl.org
Subject: [SDL] Fullscreen Vsync in Win32

I am using SDL1.2.11, WinXp, Ati X800 PCI Express videocard

I have tried setting the flags as follows:
*flags = SDL_HWSURFACE | SDL_DOUBLEBUF | SDL_FULLSCREEN;
SDL_SetVideoMode(640, 480, 32, flags);
*
When rendering the screen, I call *SDL_Flip( ).

*However, vsync does not appear to be taking place as the frame rate
exceeds 60hz or
whatever I set the monitor refresh rate to.

Please advise!

SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl

SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl

SDL mailing list
SDL at libsdl.org
http://www.libsdl.org/mailman/listinfo/sdl