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[SDL2] Resize issues
Flamaros


Joined: 14 Mar 2013
Posts: 8
Location: France
Post Posted: Sun Mar 17, 2013 8:11 pm
I have some issue when resizing window, under Windows I have not repaint and under Linux I have flickers like one frame on two.

Under linux, when I remove double-buffering flickers disappears.
[SDL2] Resize issues
Sik


Joined: 26 Nov 2011
Posts: 905
Post Posted: Sun Mar 17, 2013 9:10 pm
I think you're supposed to repaint on resizing always since the
display contents aren't guaranteed to be there anymore. If they stay
there it's pure coincidence and you shouldn't rely on it.

2013/3/17, Flamaros:
Quote:
I have some issue when resizing window, under Windows I have not repaint and
under Linux I have flickers like one frame on two.

Under linux, when I remove double-buffering flickers disappears.
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Re: [SDL2] Resize issues
Flamaros


Joined: 14 Mar 2013
Posts: 8
Location: France
Post Posted: Mon Mar 18, 2013 10:52 am
Sik wrote:
I think you're supposed to repaint on resizing always since the
display contents aren't guaranteed to be there anymore. If they stay
there it's pure coincidence and you shouldn't rely on it.

2013/3/17, Flamaros:
Quote:
I have some issue when resizing window, under Windows I have not repaint and
under Linux I have flickers like one frame on two.

Under linux, when I remove double-buffering flickers disappears.
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Yes I had try to force repaint, by calling explicitly my draw method on resize event with no effect. I know it's necessary to do it with win32 API.
I really need that feature as I am not doing a game.
[SDL2] Resize issues
Gabriele Greco
Guest
Post Posted: Mon Mar 18, 2013 11:31 am
Quote:
Yes I had try to force repaint, by calling explicitly my draw method on resize event with no effect. I know it's necessary to do it with win32 API.
I really need that feature as I am not doing a game.


I'm quite sure yoy don't need to redraw on the resize event, I think it's enough to redraw on the SDL_WINDOWEVENT_EXPOSE that you'll receive once the resize is occurred.


You have to use the resize event (SDL_WINDOWEVENT_RESIZED) only to get your new surface size.



--
Ing. Gabriele Greco, DARTS Engineering
Tel: +39-0100980150  Fax: +39-0100980184
s-mail: Piazza Della Vittoria 9/3 - 16121 GENOVA (ITALY)
Re: [SDL2] Resize issues
Flamaros


Joined: 14 Mar 2013
Posts: 8
Location: France
Post Posted: Mon Mar 18, 2013 7:14 pm
Gabriele Greco wrote:
Quote:
Yes I had try to force repaint, by calling explicitly my draw method on resize event with no effect. I know it's necessary to do it with win32 API.
I really need that feature as I am not doing a game.


I'm quite sure yoy don't need to redraw on the resize event, I think it's enough to redraw on the SDL_WINDOWEVENT_EXPOSE that you'll receive once the resize is occurred.


You have to use the resize event (SDL_WINDOWEVENT_RESIZED) only to get your new surface size.



--
Ing. Gabriele Greco, DARTS Engineering
Tel: +39-0100980150  Fax: +39-0100980184
s-mail: Piazza Della Vittoria 9/3 - 16121 GENOVA (ITALY)




Add a draw call on SDL_WINDOWEVENT_EXPOSE event don't change anything.
You may notice I am using Opengl and after the SDL_PollEvent loop I always call my draw method.
[SDL2] Resize issues
Jonny D


Joined: 12 Sep 2009
Posts: 932
Post Posted: Mon Mar 18, 2013 7:21 pm
Maybe try to draw, swap buffers, then draw again?  If disabling double-buffering helped, then this is probably what you need to do.

Jonny D



On Mon, Mar 18, 2013 at 3:14 PM, Flamaros wrote:
Quote:



Gabriele Greco wrote:




Quote:

Yes I had try to force repaint, by calling explicitly my draw method on resize event with no effect. I know it's necessary to do it with win32 API.
I really need that feature as I am not doing a game.






I'm quite sure yoy don't need to redraw on the resize event, I think it's enough to redraw on the SDL_WINDOWEVENT_EXPOSE that you'll receive once the resize is occurred.


You have to use the resize event (SDL_WINDOWEVENT_RESIZED) only to get your new surface size.



--
Ing. Gabriele Greco, DARTS Engineering
Tel: +39-0100980150  Fax: +39-0100980184
s-mail: Piazza Della Vittoria 9/3 - 16121 GENOVA (ITALY)








Add a draw call on SDL_WINDOWEVENT_EXPOSE event don't change anything.
You may notice I am using Opengl and after the SDL_PollEvent loop I always call my draw method.


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[SDL2] Resize issues
Forest Hale
Guest
Post Posted: Mon Mar 18, 2013 8:07 pm
Don't forget to call glViewport also, with the new size.

On 03/18/2013 12:21 PM, Jonathan Dearborn wrote:
Quote:
Maybe try to draw, swap buffers, then draw again? If disabling double-buffering helped, then this is probably what you need to do.

Jonny D


On Mon, Mar 18, 2013 at 3:14 PM, Flamaros <mailto:> wrote:

__



Gabriele Greco wrote:




Quote:

Yes I had try to force repaint, by calling explicitly my draw method on resize event with no effect. I know it's necessary to do it with win32 API.
I really need that feature as I am not doing a game.





I'm quite sure yoy don't need to redraw on the resize event, I think it's enough to redraw on the SDL_WINDOWEVENT_EXPOSE that you'll receive once the resize is occurred.


You have to use the resize event (SDL_WINDOWEVENT_RESIZED) only to get your new surface size.



--
Ing. Gabriele Greco, DARTS Engineering
Tel: +39-0100980150 Fax: +39-0100980184
s-mail: Piazza Della Vittoria 9/3 - 16121 GENOVA (ITALY)






Add a draw call on SDL_WINDOWEVENT_EXPOSE event don't change anything.
You may notice I am using Opengl and after the SDL_PollEvent loop I always call my draw method.

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--
LordHavoc
Author of DarkPlaces Quake1 engine - http://icculus.org/twilight/darkplaces
Co-designer of Nexuiz - http://alientrap.org/nexuiz
"War does not prove who is right, it proves who is left." - Unknown
"Any sufficiently advanced technology is indistinguishable from a rigged demo." - James Klass
"A game is a series of interesting choices." - Sid Meier

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Re: [SDL2] Resize issues
Flamaros


Joined: 14 Mar 2013
Posts: 8
Location: France
Post Posted: Tue Mar 19, 2013 9:15 pm
Certainly, for the moment I call glViewport each frame.

Forest Hale wrote:
Don't forget to call glViewport also, with the new size.

On 03/18/2013 12:21 PM, Jonathan Dearborn wrote:
Quote:
Maybe try to draw, swap buffers, then draw again? If disabling double-buffering helped, then this is probably what you need to do.

Jonny D


On Mon, Mar 18, 2013 at 3:14 PM, Flamaros <mailto:> wrote:

__



Gabriele Greco wrote:




Quote:

Yes I had try to force repaint, by calling explicitly my draw method on resize event with no effect. I know it's necessary to do it with win32 API.
I really need that feature as I am not doing a game.





I'm quite sure yoy don't need to redraw on the resize event, I think it's enough to redraw on the SDL_WINDOWEVENT_EXPOSE that you'll receive once the resize is occurred.


You have to use the resize event (SDL_WINDOWEVENT_RESIZED) only to get your new surface size.



--
Ing. Gabriele Greco, DARTS Engineering
Tel: +39-0100980150 Fax: +39-0100980184
s-mail: Piazza Della Vittoria 9/3 - 16121 GENOVA (ITALY)






Add a draw call on SDL_WINDOWEVENT_EXPOSE event don't change anything.
You may notice I am using Opengl and after the SDL_PollEvent loop I always call my draw method.

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<mailto:
http://lists.libsdl.org/listinfo.cgi/sdl-libsdl.org




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SDL mailing list

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--
LordHavoc
Author of DarkPlaces Quake1 engine - http://icculus.org/twilight/darkplaces
Co-designer of Nexuiz - http://alientrap.org/nexuiz
"War does not prove who is right, it proves who is left." - Unknown
"Any sufficiently advanced technology is indistinguishable from a rigged demo." - James Klass
"A game is a series of interesting choices." - Sid Meier

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Flamaros


Joined: 14 Mar 2013
Posts: 8
Location: France
Post Posted: Fri May 10, 2013 11:21 pm
I am back on this particular issue since I made progress on other primary parts.

I add some outputs to be able to understand what is happening. While I am resizing the window I don't get the "SDL_PollEvent" text in the console, it's only when I release the mouse button that all "SDL_WINDOWEVENT_RESIZED" messages are printed.

For the move event I receive only once when I release the mouse button.

Here is my loop code :
Code:

   while (!mQuit)
   {
      SDL_Event   event;
      while (SDL_PollEvent(&event) && !mQuit)
      {
         writeln("SDL_PollEvent");
         switch (event.type)
         {
            case SDL_QUIT:
               mQuit = true;
               break;
            case SDL_WINDOWEVENT:
               switch (event.window.event)
               {
                  case SDL_WINDOWEVENT_SHOWN:   // Called at window creation (need update opengl context size)
                     writeln("SDL_WINDOWEVENT_SHOWN");
                     if (event.window.windowID in GuiApplication.mWindows)
                        GuiApplication.mWindows[event.window.windowID].setSize(GuiApplication.mWindows[event.window.windowID].size());
                     break;
                  case SDL_WINDOWEVENT_HIDDEN:
                     writeln("SDL_WINDOWEVENT_HIDDEN");
                     break;
                  case SDL_WINDOWEVENT_EXPOSED:
                     writeln("SDL_WINDOWEVENT_EXPOSED");
                     if (event.window.windowID in GuiApplication.mWindows)
                        GuiApplication.mWindows[event.window.windowID].onPaint();
                     break;
                  case SDL_WINDOWEVENT_MOVED:
                     writeln("SDL_WINDOWEVENT_MOVED");
                     if (event.window.windowID in GuiApplication.mWindows)
                        GuiApplication.mWindows[event.window.windowID].setPosition(Vector2s32(event.window.data1, event.window.data2));
                     break;
                  case SDL_WINDOWEVENT_RESIZED:
                     writeln("SDL_WINDOWEVENT_RESIZED");
                     if (event.window.windowID in GuiApplication.mWindows)
                        GuiApplication.mWindows[event.window.windowID].setSize(Vector2s32(event.window.data1, event.window.data2));
                     break;
               }
               break;
         }
      }
      if (!mQuit)
         foreach (Window window; mWindows)
            window.onPaint();
   }
   return 0;
}
Nathaniel J Fries


Joined: 30 Mar 2010
Posts: 444
Post Posted: Sat May 11, 2013 3:08 am
On Windows, DispatchMessage() enters into a loop for as long as you're holding down the mouse button when you begin resizing your window.
Within the framework of the SDL API, there is no correction*. It would require rendering within the Window Procedure, which is impossible.

On Linux, it seems to be an issue of X11 destroying the OpenGL buffer contents during resize, which means it is probably not something that a client program can control or properly account for. I've never seen a program using OpenGL for graphics on Linux resize without some flickering.

* - Shy of some sort of mechanism to jump out of the Windows Procedure and then back in again as if no jump had occurred, such as maybe a Fiber or explicit context switching, but this would probably cause some issues too.
Flamaros


Joined: 14 Mar 2013
Posts: 8
Location: France
Post Posted: Sat May 11, 2013 5:16 pm
Nathaniel J Fries wrote:
On Windows, DispatchMessage() enters into a loop for as long as you're holding down the mouse button when you begin resizing your window.
Within the framework of the SDL API, there is no correction*. It would require rendering within the Window Procedure, which is impossible.

On Linux, it seems to be an issue of X11 destroying the OpenGL buffer contents during resize, which means it is probably not something that a client program can control or properly account for. I've never seen a program using OpenGL for graphics on Linux resize without some flickering.

* - Shy of some sort of mechanism to jump out of the Windows Procedure and then back in again as if no jump had occurred, such as maybe a Fiber or explicit context switching, but this would probably cause some issues too.


I don't have issue like that with DispatchMessage(). Currently I am using SDL under Windows, because I try to share the maximum code between platforms.

My application loop :
Code:

int   execute()
{
   MSG      msg;

   while (!mQuit)
   {
      while (PeekMessageA(&msg, null, 0, 0, PM_REMOVE))
      {
         TranslateMessage(&msg);
         DispatchMessageA(&msg);
      }
         foreach (Window window; mWindows)
         window.onPaint();
   }
   return msg.wParam;
}


The Wndproc function :
Code:

extern(Windows) LRESULT   WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) nothrow
{
   Vector2s32   size;
   Vector2s32   position;
   bool      state;

   try
   {
      switch (message)
      {
         case WM_CREATE:
            break;
         case WM_MOVE:      // position de cliet arena
            break;
         case WM_MOVING:      // position de la fenetre
            position.x = LOWORD(lParam);
            position.y = HIWORD(lParam);
            if (hWnd in GuiApplication.mWindows)
            {
               GuiApplication.mWindows[hWnd].setPosition(position);
               GuiApplication.mWindows[hWnd].onPaint();
            }
            return 0;
         case WM_SIZE:
            writeln("WM_SIZE");
            size.x = LOWORD(lParam);
            size.y = HIWORD(lParam);
            if (hWnd in GuiApplication.mWindows)
            {
               GuiApplication.mWindows[hWnd].setSize(size);
               GuiApplication.mWindows[hWnd].onPaint(); // WM_PAINT occurs before WM_SIZE
            }
            return 0;
         case WM_COMMAND:
            break;
         case WM_PAINT:
            // Certainly not necessary because paint is always call
            if (hWnd in GuiApplication.mWindows)
               GuiApplication.mWindows[hWnd].onPaint();
            break;
         case WM_DESTROY:
            if (hWnd in GuiApplication.mWindows)
               GuiApplication.mWindows[hWnd].destroy();
            PostQuitMessage(0);
            break;

            // TODO manage the WM_ACTIVATE event for fullscreen
         default:
            break;
      }
   }
   catch (Throwable e)
   {
      collectException(MessageBoxA(null, e.toString().toStringz, "Error", MB_OK | MB_ICONEXCLAMATION));   // PS: string.toString() method is not nothrow
   }
   return DefWindowProcA(hWnd, message, wParam, lParam);
}


With this code "WM_SIZE" is printed during the window resize not only when I release the mouse button.
Flamaros


Joined: 14 Mar 2013
Posts: 8
Location: France
Post Posted: Sat May 11, 2013 5:19 pm
You may have a look to the answer 2 of this stackoverflow question :
http://stackoverflow.com/questions/3102074/win32-my-application-freezes-while-the-user-resizes-the-window