VisualC.html
author Sam Lantinga <slouken@libsdl.org>
Thu, 17 Apr 2014 22:36:14 -0700
branchSDL-1.2
changeset 8716 0aade9c0203f
parent 5893 f3adae5e12cd
permissions -rw-r--r--
Fixed bug 2325 - SDL_EnableUNICODE sometimes drops keyboard events completely

Rafał Mużyło

The most annoying part of this bug is that though I've found it in two separate apps, I don't have a trivial testcase for it.

The problem seems to be a condition race, as it's triggered quite randomly (therefore it will be hard to tell whether it really gets fixed, if a probable fix is found).

While it's specific to SDL 1.2, it seems quite similar to the problem described and fixed in http://forums.libsdl.org/viewtopic.php?p=40503.

Now, I should start describing the problem.

A game uses Escape to open menu (the exact key might not be important). Upon opening, it calls SDL_EnableUNICODE(1). Upon closing it calls SDL_EnableUNICODE(0).

I have an IME running.

Game uses SDL_PollEvent to get the events.

If Escape is pressed repeatedly, menu is opened and closed, till it eventually freezes in open state.
"freezes" in this context means "app itself still runs, but no keyboard events are getting delivered (though - for example - mouse events still are)". "getting delivered" should mean "SDL_PollEvent is not receiving any".
If it matters, the last delivered keyboard event is a keypress, the release never arrives.

It seems (no guarantees, due to random nature of the freeze) that unsetting XMODIFIERS (which - AFAIU - will disable IME as far as SDL is concerned) prevents the freeze, therefore the reference to that SDL2 thread.
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<HTML>
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	<HEAD>
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		<TITLE>Using SDL with Microsoft Visual C++</TITLE>
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	</HEAD>
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	<BODY>
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		<H1>
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			Using SDL with Microsoft Visual C++ 5,6&nbsp;and 7
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		</H1>
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		<H3>
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			by <A HREF="mailto:snowlion@sprynet.com">Lion Kimbro </A>and additions by <A HREF="mailto:james@conceptofzero.net">
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				James Turk</A>
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		</H3>
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		<p>
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			You can either use the precompiled libraries from <A HREF="http://www.libsdl.org/download.php">
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				the SDL Download web site </A>, or you can build SDL yourself.
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		</p>
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		<H3>
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			Building SDL
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		</H3>
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		<P>
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			Go into the VisualC
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			directory that is created, and double-click on the VC++ file "<CODE>SDL.dsw</CODE>"<STRONG><FONT color="#009900">
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					("<CODE>SDL.sln</CODE>").</FONT></STRONG> This should open up the IDE.
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		</P>
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		<P>
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			You may be prompted at this point to upgrade the workspace, should you be using 
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			a more recent version of Visual C++. If so, allow the workspace to be upgraded.
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		</P>
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		<P>
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			Build the <CODE>.dll</CODE> and <CODE>.lib</CODE> files.
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		</P>
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		<P>
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			This is done by right clicking on each project in turn (Projects are listed in 
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			the Workspace panel in the FileView tab), and selecting "Build".
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		</P>
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		<P>
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			If you get an error about SDL_config.h being missing, you should
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			copy include/SDL_config.h.default to include/SDL_config.h and try again.
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		</P>
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		<P>
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			You may get a few warnings, but you should not get any errors. You do have to 
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			have at least the DirectX 5 SDK installed, however. The latest 
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			version of DirectX can be downloaded or purchased on a cheap CD (my 
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			recommendation) from <A HREF="http://www.microsoft.com">Microsoft </A>.
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		</P>
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		<P>
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			Later, we will refer to the following .lib and .dll files that have just been 
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			generated:
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		</P>
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		<ul>
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    <li> SDL.dll</li>
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    <li> SDL.lib</li>
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    <li> SDLmain.lib</li>
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    </ul>
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		<P>
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			Search for these using the Windows Find (Windows-F) utility, if you don't 
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			already know where they should be. For those of you with a clue, look inside 
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			the Debug or Release directories of the subdirectories of the Project folder. 
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			(It might be easier to just use Windows Find if this sounds confusing. And 
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			don't worry about needing a clue; we all need visits from the clue fairy 
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			frequently.)
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		</P>
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		<H3>
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			Creating a Project with SDL
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		</H3>
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		<P>
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			Create a project as a Win32 Application.
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		</P>
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		<P>
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			Create a C++ file for your project.
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		</P>
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		<P>
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			Set the C runtime to "Multi-threaded DLL" in the menu: <CODE>Project|Settings|C/C++ 
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				tab|Code Generation|Runtime Library </CODE>.
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		</P>
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		<P>
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			Add the SDL <CODE>include</CODE> directory to your list of includes in the 
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			menu: <CODE>Project|Settings|C/C++ tab|Preprocessor|Additional include directories </CODE>
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			.
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			<br>
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			<STRONG><FONT color="#009900">VC7 Specific: Instead of doing this I find it easier to 
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					add the include and library directories to the list that VC7 keeps. Do this by 
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					selecting Tools|Options|Projects|VC++ Directories and under the "Show 
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					Directories For:" dropbox select "Include Files", and click the "New Directory 
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					Icon" and add the [SDLROOT]\include directory (ex. If you installed to 
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					c:\SDL-1.2.5\ add c:\SDL-1.2.5\include).&nbsp;Proceed to&nbsp;change the 
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					dropbox selection to "Library Files" and add [SDLROOT]\lib.</FONT></STRONG>
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		</P>
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			<P>
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				The "include directory" I am referring to is the <CODE>include</CODE> folder 
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				within the main SDL directory (the one that this HTML file located within).
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			</P>
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			<P>
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				Now we're going to use the files that we had created earlier in the Build SDL 
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				step.
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			</P>
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			<P>
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				Copy the following files into your Project directory:
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			</P>
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			<ul>
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     <li> SDL.dll</li>
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     </ul>
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			<P>
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				Add the following files to your project (It is not necessary to copy them to 
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				your project directory):
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			</P>
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			<ul>
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     <li> SDL.lib </li>
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     <li> SDLmain.lib</li>
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     </ul>
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			<P>
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				(To add them to your project, right click on your project, and select "Add 
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				files to project")
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			</P>
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		<P><STRONG><FONT color="#009900">Instead of adding the files to your project it is more 
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					desireable to add them to the linker options: Project|Properties|Linker|Command 
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					Line and type the names of the libraries to link with in the "Additional 
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					Options:" box.&nbsp; Note: This must be done&nbsp;for&nbsp;each&nbsp;build 
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					configuration (eg. Release,Debug).</FONT></STRONG></P>
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		<H3>
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			SDL 101, First Day of Class
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		</H3>
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		<P>
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			Now create the basic body of your project. The body of your program should take 
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			the following form: <CODE>
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				<PRE>
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#include "SDL.h"
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int main( int argc, char* argv[] )
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{
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  // Body of the program goes here.
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  return 0;
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}
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</PRE>
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			</CODE>
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		<P></P>
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		<H3>
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			That's it!
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		</H3>
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		<P>
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			I hope that this document has helped you get through the most difficult part of 
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			using the SDL: installing it. Suggestions for improvements to this document 
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			should be sent to the writers of this document.
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		</P>
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		<P>
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			Thanks to Paulus Esterhazy (pesterhazy@gmx.net), for the work on VC++ port.
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		</P>
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		<P>
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			This document was originally called "VisualC.txt", and was written by <A HREF="mailto:slouken@libsdl.org">
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				Sam Lantinga</A>.
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		</P>
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		<P>
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			Later, it was converted to HTML and expanded into the document that you see 
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			today by <A HREF="mailto:snowlion@sprynet.com">Lion Kimbro</A>.
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		</P>
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		<P>Minor Fixes and Visual C++ 7 Information (In Green) was added by <A HREF="mailto:james@conceptofzero.net">James Turk</A>
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		</P>
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	</BODY>
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</HTML>