kaizen/external/SDL/docs/README-macos.md

macOS

These instructions are for people using Apple's macOS.

From the developer's point of view, macOS 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.

Command Line Build

To build SDL using the command line, use the CMake build script:

mkdir build
cd build
cmake .. -DCMAKE_OSX_DEPLOYMENT_TARGET=10.13
cmake --build .
sudo cmake --install .

You can also build SDL as a Universal library (a single binary for both 64-bit Intel and ARM architectures):

mkdir build
cd build
cmake .. "-DCMAKE_OSX_ARCHITECTURES=arm64;x86_64" -DCMAKE_OSX_DEPLOYMENT_TARGET=10.13
cmake --build .
sudo cmake --install .

Please note that building SDL requires at least Xcode 12.2 and the macOS 11.0 SDK.

If you are getting errors building SDL_mfijoystick.m with Xcode 12.2, find your SDKs directory and move MacOSX10.15.sdk out of the way so it isn't accidentally being used by the build environment.

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

Caveats for using SDL with macOS

If you register your own NSApplicationDelegate (using [NSApp setDelegate:]), SDL will not register its own. This means that SDL will not terminate using SDL_Quit if it receives a termination request, it will terminate like a normal app, and it will not send a SDL_EVENT_DROP_FILE when you request to open a file with the app. To solve these issues, put the following code in your NSApplicationDelegate implementation:

- (NSApplicationTerminateReply)applicationShouldTerminate:(NSApplication *)sender
{
    if (SDL_EventEnabled(SDL_EVENT_QUIT)) {
        SDL_Event event;
        SDL_zero(event);
        event.type = SDL_EVENT_QUIT;
        SDL_PushEvent(&event);
    }

    return NSTerminateCancel;
}

- (BOOL)application:(NSApplication *)theApplication openFile:(NSString *)filename
{
    if (SDL_EventEnabled(SDL_EVENT_DROP_FILE)) {
        SDL_Event event;
        SDL_zero(event);
        event.type = SDL_EVENT_DROP_FILE;
        event.drop.file = SDL_strdup([filename UTF8String]);
        return SDL_PushEvent(&event);
    }

    return NO;
}

SDL is not designed to be used in setuid or setgid executables.

Using the Simple DirectMedia Layer with a traditional Makefile

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

To get this build automatically, add something like the following rule to your Makefile.am:

bundle_contents = APP_NAME.app/Contents
APP_NAME_bundle: EXE_NAME
	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 configure.ac 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 Makefile.am:

install-exec-hook: APP_NAME_bundle
	rm -rf $(DESTDIR)$(prefix)/Applications/APP_NAME.app
	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 barebones .app bundle, which is double-clickable from the Finder. But there are some more things you should do before shipping your product...

1. You'll need to copy the SDL framework into the Contents/Frameworks folder in your bundle, so it is included along with your application.

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:

• ~/Library/Frameworks
• /Local/Library/Frameworks
• /System/Library/Frameworks

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:

(this is accurate as of Xcode 12.5.)

• Click "File" -> "New" -> "Project...
• Choose "macOS" and then "App" from the "Application" section.
• Fill out the options in the next window. User interface is "XIB" and Language is "Objective-C".
• Remove "main.m" from your project
• Remove "MainMenu.xib" from your project
• Remove "AppDelegates.*" 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"
• Add your files
• Clean and build

Building from command line

Use xcode-build in the same directory as your .pbxproj 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

In SDL 1.2, the working directory of your SDL app is by default set to its parent, but this is no longer the case in SDL 2.0 and later. SDL2 does not change the working directory, which means it'll be whatever the command line prompt that launched the program was using, or if launched by double-clicking in the Finder, it will be "/", the root of the filesystem. Plan accordingly! You can use SDL_GetBasePath() to find where the program is running from and chdir() there directly.

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.

Raw Mouse Input

On macOS 11.0 (Big Sur) and later, SDL uses the Game Controller framework's GCMouse API to provide raw, unaccelerated mouse input in relative mode. This is ideal for games and applications requiring precise 1:1 mouse movement.

On older macOS versions, SDL falls back to NSEvent-based mouse input, which includes system mouse acceleration.

To use accelerated (system-scaled) mouse movement on macOS 11.0+, set the hint:

SDL_SetHint(SDL_HINT_MOUSE_RELATIVE_SYSTEM_SCALE, "1");

Bug reports

Bugs are tracked at the GitHub issue tracker. Please feel free to report bugs there!