author Sam Lantinga <>
Sat, 27 Jul 2013 03:20:09 -0700
changeset 7526 6c0f0280149c
parent 7222 2435b221d77d
child 7801 f00cc0a8cd5d
permissions -rw-r--r--
Fixed bug 1272 - Bogus numlock key up/down events being reported on MacOS X Vern Jensen The problem is that in certain situations I'm getting THREE keyUp/keyDown events when I push certain keys. In my event code I added: case SDL_KEYUP: printf("SDL KeyScanCode for KEYUP event: %d\n", event->key.keysym.scancode ); … and case SDL_KEYDOWN: printf("SDL KeyScanCode for KEYDOWN event: %d\n", event->key.keysym.scancode ); … The result of one test run where I push 2 keys and then release them is this: SDL KeyScanCode for KEYDOWN event: 92 // Pushed keypad 4 SDL KeyScanCode for KEYDOWN event: 83 // Pushed left shift SDL KeyScanCode for KEYUP event: 83 SDL KeyScanCode for KEYDOWN event: 225 SDL KeyScanCode for KEYUP event: 92 // Released keypad 4 SDL KeyScanCode for KEYDOWN event: 83 SDL KeyScanCode for KEYUP event: 83 SDL KeyScanCode for KEYUP event: 225 // Released left shift There *should* be only a total of 4 events above… 2 for each key being pushed, and 2 for each being released. But instead some bogus events for numlock being pushed/released are sent from SDL. These events did not occur. I did not push numlock. The value above for numlock is 83. Comments above show when I pushed each key. As you can see, when I push left shift, THREE events are instantly sent to my application, keyDown and then keyUp for numlock, and then the valid event for left shift (the key that was actually pushed). You could replace keypad 4 with pretty much any keyPad key and it'll still happen. You can also replace it with any arrow key and it'll happen. However, when trying it with normal letter keys on the main keyboard it didn't. It happens with other modifier keys too, not just left shift. The order in which the keys are pressed matter. For instance, if I do: 1) keypad 4 2) left shift 3) release left shift 4) release keypad 4 Then at step 2, I get the 3 events above (when there should be only one), but steps 3 and 4 work properly… I don't get extra keyUp/keyDown events for steps 3 or 4. Thereas if the order of steps 3 and 4 are reversed, I get the bogus extra events for numlock. Also, the problem can occur even when pushing just a single key by itself. If I push left shift, then keypad 4, then release left shift, then release keypad 4, then the following push of left shift will cause the bug. If I continue pushing and releasing left shift though, it won't happen again until I again involve keypad keys. --- Sam Lantinga According to the Apple documentation, NSNumericPadKeyMask is set for any arrow or numeric keypad event. Indeed this is what's happening. I verified that we get the correct events for the numlock key and the mod state gets set correcly, so it should be safe to remove this bogus code.

Using the Simple DirectMedia Layer with Mac OS X

These instructions are for people using Apple's Mac OS X (pronounced

From the developer's point of view, OS X is a sort of hybrid Mac and
Unix system, and you have the option of using either traditional
command line tools or Apple's IDE Xcode.

To build SDL using the command line, use the standard configure and make

	sudo make install

You can also build SDL as a Universal library (a single binary for both
PowerPC and Intel architectures), on Mac OS X 10.4 and newer, by using
the script in build-scripts:
	sh build-scripts/
	sudo build-scripts/ install
This script builds SDL with 10.2 ABI compatibility on PowerPC and 10.4
ABI compatibility on Intel architectures.  For best compatibility you
should compile your application the same way.  A script which wraps
gcc to make this easy is provided in test/

To use the library once it's built, you essential have two possibilities:
use the traditional autoconf/automake/make method, or use Xcode.

Using the Simple DirectMedia Layer with a traditional Makefile

An existing autoconf/automake build system for your SDL app has good chances
to work almost unchanged on OS X. However, to produce a "real" Mac OS X binary
that you can distribute to users, you need to put the generated binary into a
so called "bundle", which basically is a fancy folder with a name like

To get this build automatically, add something like the following rule to

bundle_contents =
	mkdir -p $(bundle_contents)/MacOS
	mkdir -p $(bundle_contents)/Resources
	echo "APPL????" > $(bundle_contents)/PkgInfo
	$(INSTALL_PROGRAM) $< $(bundle_contents)/MacOS/

You should replace EXE_NAME with the name of the executable. APP_NAME is what
will be visible to the user in the Finder. Usually it will be the same
as EXE_NAME but capitalized. E.g. if EXE_NAME is "testgame" then APP_NAME 
usually is "TestGame". You might also want to use @PACKAGE@ to use the package
name as specified in your file.

If your project builds more than one application, you will have to do a bit
more. For each of your target applications, you need a separate rule.

If you want the created bundles to be installed, you may want to add this
rule to your

install-exec-hook: APP_NAME_bundle
	rm -rf $(DESTDIR)$(prefix)/Applications/
	mkdir -p $(DESTDIR)$(prefix)/Applications/
	cp -r $< /$(DESTDIR)$(prefix)Applications/

This rule takes the Bundle created by the rule from step 3 and installs them
into $(DESTDIR)$(prefix)/Applications/.

Again, if you want to install multiple applications, you will have to augment
the make rule accordingly.

But beware! That is only part of the story! With the above, you end up with
a bare bone .app bundle, which is double clickable from the Finder. But
there are some more things you should do before shipping your product...

1) The bundle right now probably is dynamically linked against SDL. That 
   means that when you copy it to another computer, *it will not run*,
   unless you also install SDL on that other computer. A good solution
   for this dilemma is to static link against SDL. On OS X, you can
   achieve that by linking against the libraries listed by
     sdl-config --static-libs
   instead of those listed by
     sdl-config --libs
   Depending on how exactly SDL is integrated into your build systems, the
   way to achieve that varies, so I won't describe it here in detail
2) Add an 'Info.plist' to your application. That is a special XML file which
   contains some meta-information about your application (like some copyright
   information, the version of your app, the name of an optional icon file,
   and other things). Part of that information is displayed by the Finder
   when you click on the .app, or if you look at the "Get Info" window.
   More information about Info.plist files can be found on Apple's homepage.

As a final remark, let me add that I use some of the techniques (and some
variations of them) in Exult and ScummVM; both are available in source on
the net, so feel free to take a peek at them for inspiration!

Using the Simple DirectMedia Layer with Xcode

These instructions are for using Apple's Xcode IDE to build SDL applications.

- First steps

The first thing to do is to unpack the Xcode.tar.gz archive in the
top level SDL directory (where the Xcode.tar.gz archive resides).
Because Stuffit Expander will unpack the archive into a subdirectory,
you should unpack the archive manually from the command line:
	cd [path_to_SDL_source]
	tar zxf Xcode.tar.gz
This will create a new folder called Xcode, which you can browse
normally from the Finder.

- Building the Framework

The SDL Library is packaged as a framework bundle, an organized
relocatable folder hierarchy of executable code, interface headers,
and additional resources. For practical purposes, you can think of a 
framework as a more user and system-friendly shared library, whose library
file behaves more or less like a standard UNIX shared library.

To build the framework, simply open the framework project and build it. 
By default, the framework bundle "SDL.framework" is installed in 
/Library/Frameworks. Therefore, the testers and project stationary expect
it to be located there. However, it will function the same in any of the
following locations:


- Build Options
    There are two "Build Styles" (See the "Targets" tab) for SDL.
    "Deployment" should be used if you aren't tweaking the SDL library.
    "Development" should be used to debug SDL apps or the library itself.

- Building the Testers
    Open the SDLTest project and build away!

- Using the Project Stationary
    Copy the stationary to the indicated folders to access it from
    the "New Project" and "Add target" menus. What could be easier?

- Setting up a new project by hand
    Some of you won't want to use the Stationary so I'll give some tips:
    * Create a new "Cocoa Application"
    * Add src/main/macosx/SDLMain.m , .h and .nib to your project
    * Remove "main.c" from your project
    * Remove "MainMenu.nib" from your project
    * Add "$(HOME)/Library/Frameworks/SDL.framework/Headers" to include path
    * Add "$(HOME)/Library/Frameworks" to the frameworks search path
    * Add "-framework SDL -framework Foundation -framework AppKit" to "OTHER_LDFLAGS"
    * Set the "Main Nib File" under "Application Settings" to "SDLMain.nib"
    * Add your files
    * Clean and build

- Building from command line
    Use pbxbuild in the same directory as your .pbproj file

- Running your app
    You can send command line args to your app by either invoking it from
    the command line (in *.app/Contents/MacOS) or by entering them in the
    "Executables" panel of the target settings.
- Implementation Notes
    Some things that may be of interest about how it all works...
    * Working directory
        As defined in the SDL_main.m file, the working directory of your SDL app
        is by default set to its parent. You may wish to change this to better
        suit your needs.
    * You have a Cocoa App!
        Your SDL app is essentially a Cocoa application. When your app
        starts up and the libraries finish loading, a Cocoa procedure is called,
        which sets up the working directory and calls your main() method.
        You are free to modify your Cocoa app with generally no consequence 
        to SDL. You cannot, however, easily change the SDL window itself.
        Functionality may be added in the future to help this.

Known bugs are listed in the file "BUGS"