Allegro MacOS X-specific information

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                    MacOS X-specific information.

             See readme.txt for a more general overview.

# MacOS X notes

This is a full featured native MacOS X port. The whole codebase is young, so it may hold some bugs; feedback is welcome!

# Required software

To build Allegro under MacOS X, you need:

- MacOS X 10.2.x or newer
- Apple Developer Tools (December 2002 or newer edition)

If you don't have the Developer Tools installed, you can get the latest release at:

> http://developer.apple.com/tools/download

On the same page you will also find instructions on how to install them. Note that system version 10.2.x is required to compile Allegro, but the library will still work on 10.1.x.

# Installing Allegro

Allegro ships in source code form; this means you need to compile it before you can use it. You do this easily from a terminal window. Due to the multiplatform nature of the library, the first step is to fix it so it can be built under MacOS X, by running:

>           chmod +x fix.sh
>           ./fix.sh macosx

If you have checked out a development version from Allegro's SVN repository, run the following command. Otherwise, skip this step:

>           make depend

Now Allegro is ready to be compiled. Start building it:

>           make

And finally you install it (you need the root password for this step):

>           sudo make install

Allegro has now been installed in your system as a standalone shared library, in `/usr/local/lib`. You may also wish to install the man pages:

>           sudo make install-man

Alternatively, you can view the documentation in the Mac Help Center:

>           sudo make install-applehelp

You may also wish to install the library as a standard MacOS X framework:

>           sudo make install-framework

The "Allegro" framework will be created into `/Library/Frameworks`. Note that the framework is standalone: it contains its own copy of the dynamic library, so it can be safely copied around. If you plan to embed the Allegro framework inside your application bundles, you must install a special embeddable version of it:

>           sudo make install-framework EMBED=1

Embedding the framework into your application bundles ensures they will work also on machines where Allegro is not installed. Note that if you embed the non-embeddable version of the framework into your app bundle, your program will not be able to load it and it will not work. Finally, if you plan on using Project Builder to code your apps, you may find useful installing an Allegro application PB project template:

>           sudo make install-template

The dynamically linked version of the library gets built by default, but if you want to build a statically linked one, write the following on the command line:

>           export STATICLINK=1

In the same manner we can also enter one of the following lines to build either the debug or the profiling version of the library:

>           export DEBUGMODE=1
>           export PROFILEMODE=1

Then restart the build process by issuing:

>           make
>           sudo make install

The static library will be installed in `/usr/local/lib` as the shared one, but you will not be able to install the framework nor the Project Builder template, which require a dynamically linked Allegro version.

If you have OS X 10.4 and you want to build a Universal Binary version of the library (i.e. one that will run on both PowerPC and Intel Macs) you can type

>           ./fix.sh macosx-universal

instead of the `fix.sh` line given above. Note that you'll still need to specify the appropriate flags when you link your program, otherwise gcc will 'thin' the binary so it only includes the native code.

For more information see http://developer.apple.com/documentation/MacOSX/Conceptual/universal_binary/

# Using Allegro from the command line

The options for linking with Allegro are quite long, expecially for static versions of the library as you need to pull in several different frameworks (Cocoa, QuickTime, etc.) other than Allegro itself. When linking against the shared library version, things are also different. To avoid you having to work out the right linker commands for yourself, the installation creates a script, `allegro-config`, that will print out a suitable commandline. You can use this inside a backtick command substitution, for example:

>           gcc myfile.c -o myprogram `allegro-config --libs`

Or if you want to build a debug version of your program, assuming that you have installed the debug version of Allegro:

>           gcc myfile.c -o myprogram `allegro-config --libs debug`

You can also link against the Allegro framework, providing you previously installed it via `make install-framework`:

>           gcc myfile.c -o myprogram `allegro-config --frameworks`

Unix newbies, take note that these are ` backticks, not normal ' quotes!

There are also switches for printing out the Allegro version number, overriding the install paths, and selecting between shared and static libraries, in case you installed both. Run `allegro-config` without any arguments for a full list of options.

If you get an error like '`allegro-config: program not found`', and you're sure you have built and installed the library as described above, it probably means that `/usr/local/bin` is not on your path. The method to add it depends on the shell you're using. If you have tcsh, add the following line to the end of the `.cshrc` in your home directory.

>          set path=($path /usr/local/bin)

If you have bash, add the following line to the end of the `.bash_profile` file in your home directory:

>          PATH=${PATH}:/usr/local/bin

If you don't know which, just type `echo $SHELL` on the command line, which will print either `/bin/bash` or `/bin/tcsh`. Newer versions of OSX use bash, older ones use tcsh. You will have to close the Terminal window and open a new one once you have made the changes, so it will have an effect.

# Using Allegro from Project Builder (or XCode)

To use Allegro from inside Apple's Project Builder, be sure you first installed the library as a framework and that you also installed the PB application template (see section "Installing Allegro" for details).

Once you're ready, start up Project Builder and choose "New Project" from the "File" menu. On the very first dialog, you'll be prompted with a list of project templates with which to create your program. Select "Allegro Application" under the "Application" category and enter the project name and location in the next dialog. Once the setup is complete, you will find yourself with an opened Allegro application project, holding an unique source file (`main.c`) and some linked frameworks. The project can already be compiled to a working application; try it!

Note that the same procedure applies to XCode, which is compatible with Project Builder.

The `main.c` source file contains a very simple skeleton of an Allegro program that will open up a white window with the text "Hello, world!" in the center. This file is just a start: you can (and should) completely replace its contents to suit your needs.

# Allegro and application bundles

When you build applications from the command line, you're actually just creating the executable, so you can run it from the command line only, and not also from the finder like a common MacOS X application. In other words, compiling from the command line does not create application bundles.

Allegro ships with a little tool, named fixbundle, which allows to build an application bundle out of an executable. The utility works from the command line and it accepts a variety of options to customize your bundle; the easiest way to use it is:

>           fixbundle executable_name

This will create an application bundle named "`executable_name.app`" that contains your program executable and will appear in the finder with the default application icon. A more complex usage example follows:

>           fixbundle executable_name -m -o bundle_name -v "1.2" icon.bmp

This creates a bundle named "`bundle_name.app`". The executable will be moved instead of copied into the bundle; the application will be marked as version "1.2" and icon.bmp will be converted to an icon for the bundle. You can specify more options and up to 4 differently sized icons (16x16, 32x32, 48x48 and 128x128) to be read from any Allegro supported image files or from datafile objects. Run fixbundle without arguments for the full list of known options.

A special note is required for the "`-e`" switch; this lets you embed the Allegro framework inside the built application bundle, so your app will not require Allegro to be installed into the target machine in order to work. This flag assumes you previously installed the embeddable version of the Allegro framework, and that your executable has been linked to it, either via Project Builder or XCode, either via the allegro-config script. If one of these conditions is not met, the created app may not work on target machines.

Bundles created by fixbundle have this default layout:

>           bundle.app --- Contents --+--- MacOS --- executable
>                                     |
>                                     +--- Resources --+--- (bundle.icns)
>                                     |                |
>                                     |                +--- (executable/...)
>                                     |
>                                     |
>                                     +--- (Frameworks) --- (Allegro.framework/...)
>                                     |
>                                     +--- Info.plist
>                                     |
>                                     +--- PkgInfo

If you are using Project Builder to compile your programs, there is no need to use fixbundle, as the IDE will do the work of generating an application bundle for you.

When an Allegro program starts, it automatically detects if the executable lives inside a bundle or not. The working directory is always set up to be the directory where the standalone executable or application bundle is located, but there is an exception: if the application is a bundle and Allegro finds a directory under the bundle Contents/Resources path with the same name of the executable (note that here we mean the real executable name, not the bundle name), that directory is set to be the working one. This allows to easily package all the application data inside the bundle, and still have a working program without the need to tell your code about the changed location of your files.

# Notes on drivers

This section contains MacOS X-specific notes on the drivers available.

> System:
>   When the system driver is about to be initialized, we already have a working NSApplication object connected to the Window Server. At driver startup, the working directory is changed if inside a bundle with a proper data directory under the Contents/Resources path (see above).

>   Display switching is possible, but only the SWITCH_BACKGROUND mode is supported, so your application will have to deal with it.

> Graphics:
>   The MacOS X windowed graphics mode uses a Cocoa window with a Quartz QuickDraw view as its content view. All combinations of window/desktop color depths are supported; if needed, color conversion will automatically be done transparently to the user.

>   Fullscreen mode uses the CoreGraphics DirectDisplay API; only 8, 15 and 32 bit color depths are supported.

> Sound:
>   The CoreAudio digital/MIDI drivers use V2 AudioUnits, and thus they require MacOS X 10.2.x (Jaguar) or newer to work. If this is not the case, you can fall back to the Carbon Sound Manager and Quicktime MIDI drivers.

> Keyboard:
>   MacOS X Allegro uses the current system keyboard mapping table to map scancodes to characters: the keyboard user settings in allegro.cfg have no effect.

> Mouse:
>   On MacOS X 10.2.x (Jaguar) or newer, Allegro will automatically detect the number of buttons of your mouse at driver initialization. If the 1-button Apple mouse is found, the library will activate an emulation mode that mimics the way MacOS X itself deals with 1-button mice: depending on which key is pressed when the button is clicked, Allegro will report a different mouse button click. (Control + button) emulates a right click and (Option + button) emulates a middle click.

>   On MacOS X 10.1.x, mouse autodetection is not possible, and Allegro will assume an 1-button mouse to always be present, activating buttons emulation accordingly.

# Final notes

There is a known compatibility problem when using gcc 4 on MacOS X 10.4 that prevents binaries from working on older versions of MacOS X. While it is anticipated that a future update from Apple will fix this problem, you can use gcc 3 to work around it.

As a final note, when coding Allegro programs don't forget that you need to use the `END_OF_MAIN()` macro right after your `main()` function!