superbuild/modules/SDL2/docs/README-macos.md

# Mac OS X (aka macOS).

These instructions are for people using Apple's Mac OS X (pronounced
"ten"), which in newer versions is just referred to as "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 standard configure and make
process:

```bash
mkdir build
cd build
../configure
make
sudo make install
```

CMake is also known to work, although it continues to be a work in progress:

```bash
mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=Release ..
make
sudo make install
```


You can also build SDL as a Universal library (a single binary for both
64-bit Intel and ARM architectures), by using the build-scripts/clang-fat.sh
script.

```bash
mkdir build
cd build
CC=$PWD/../build-scripts/clang-fat.sh ../configure
make
sudo make install
```

This script builds SDL with 10.6 ABI compatibility on 64-bit Intel and 11.0
ABI compatibility on ARM64 architectures.  For best compatibility you
should compile your application the same way.

Please note that building SDL requires at least Xcode 4.6 and the 10.7 SDK
(even if you target back to 10.6 systems). PowerPC support for Mac OS X has
been officially dropped as of SDL 2.0.2. 32-bit Intel, using an older Xcode
release, is still supported at the time of this writing, but current Xcode
releases no longer support it, and eventually neither will SDL.

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 Mac OS X

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_DROPFILE when you request to open a
file with the app. To solve these issues, put the following code in your
NSApplicationDelegate implementation:


```objc
- (NSApplicationTerminateReply)applicationShouldTerminate:(NSApplication *)sender
{
    if (SDL_GetEventState(SDL_QUIT) == SDL_ENABLE) {
        SDL_Event event;
        event.type = SDL_QUIT;
        SDL_PushEvent(&event);
    }
    
    return NSTerminateCancel;
}
    
- (BOOL)application:(NSApplication *)theApplication openFile:(NSString *)filename
{
    if (SDL_GetEventState(SDL_DROPFILE) == SDL_ENABLE) {
        SDL_Event event;
        event.type = SDL_DROPFILE;
        event.drop.file = SDL_strdup([filename UTF8String]);
        return (SDL_PushEvent(&event) > 0);
    }
    
    return NO;
}
```

# 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 macOS. 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:

```make
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:

```make
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. 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

   ```bash
   sdl-config --static-libs
   ```

   instead of those listed by

   ```bash
   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](https://github.com/exult/exult) and
[ScummVM](https://github.com/scummvm/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:

```bash
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. SDL2 does 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 finger, 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.

# Bug reports

Bugs are tracked at [the GitHub issue tracker](https://github.com/libsdl-org/SDL/issues/).
Please feel free to report bugs there!