Notes on building the MinGW/Cygwin version of Allegro.

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       Notes on building the MinGW/Cygwin version of Allegro.

       See readme.txt for a more general overview.

# MinGW notes

This is a complete MinGW port of Allegro.

The screensaver example is built, but you must copy `scrsave.scr` to your `windows/system` directory (or `winnt/system32` directory under Windows NT/2k/XP) if you want to test it.

# Obtaining and installing the compiler & tools

You have four choices when it comes to installing MinGW and Allegro on your computer:

- The section 'Setting up MinGW to build Allegro' describes how to set up the MinGW command line tools which is the preferred choice for those who like to work on the command line.
- The section 'Setting up Dev-C++ to build Allegro' describes how to set up the Dev-C++ environment to work with Allegro. This is the preferred choice for those who like to work in a graphical development environment.
- The section 'Setting up Cygwin to build Allegro' describes how to set up your Cygwin compiler to build Allegro. Cygwin offers a mature Unix-like environment for you to work in.
- The last section 'Cross compilation' describes how to set up the MinGW command line tools to compile Win32 programs from your Linux box.

Note: You will need a program to decompress .zip, .tar.gz and optionally .tar.bz2 files. I recommend PowerArchiver (shareware) which can be downloaded from: 'http://www.powerarchiver.com'.

# Setting up MinGW to build Allegro

The procedure is as follows:

> 1. Make sure you have a working MinGW installation. You can download the complete distribution or individual packages from 'http://www.mingw.org' or 'http://sourceforge.net/projects/mingw/'. You can also use the Minimal SYStem (MSYS) environment with Allegro.

> 2. Get the minimal DirectX 7 SDK for MinGW (`dx70_mgw.zip`). You download it from 'http://alleg.sourceforge.net/wip.html'. Note that this is *not* the same package as '`dx70_min.zip`'. Unzip it to the compiler directory, overwriting any existing files.

> 3. Optionally, set the environment variable MINGDIR to the compiler directory. If you use Windows 9x, you can add the line

> >              set MINGDIR=c:\MinGW

> to your '`c:\autoexec.bat`' file, assuming '`c:\MinGW`' is the compiler directory, and reboot. If you use Windows ME, you can run '`msconfig`', select the 'Environment' tab and then add `MINGDIR`. If you use Windows NT/2k/XP, you can open the Control Panel, click the 'System' applet, the 'Advanced' tab and finally the 'Environment' button, and then add `MINGDIR`. If you use MSYS, add instead the line

> >              export MINGDIR=/mingw

> to your '`c:\msys\etc\profile`' file.

Test the installation by typing the following on the command line: '`gcc -v`'. The answer should be similar to:

>           Reading specs from ../lib/gcc-lib/mingw32/3.2/specs
>           Configured with: ../gcc/configure --with-gcc --with-gnu-ld
>           --with-gnu-as --host=mingw32 --target=mingw32 --prefix=/mingw
>           --enable-threads --disable-nls --enable-languages=f77,c++,objc,ada
>           --disable-win32-registry --disable-shared
>           Thread model: win32
>           gcc version 3.2 (mingw special 20020817-1)

If you don't know how to open a terminal, you can click on '`Start -> Run`' then type "`command`". Under Windows 2k/XP, you should type "`cmd`" instead.

# Setting up Dev-C++ to build Allegro

Note: we assume that the complete version of the Dev-C++ environment (i.e with the bundled MinGW compiler) is used. If you use instead Dev-C++ as a mere IDE on top of an already installed MinGW compiler, follow the instructions given in the previous section.

The procedure is as follows:

> 1. Make sure you have a working Dev-C++ installation. You can download the complete version from 'http://bloodshed.net/dev/devcpp.html'.

> 2. Get the DirectX SDK: go to Tools\Check for Updates/Packages... and install the DirectX package. Close Dev-C++.

> 3. Add '`c:\DevCpp\bin`' to the beginning of your `PATH` environment variable. Optionally, set the environment variable MINGDIR to '`c:\DevCpp`'. If you use Windows 9x, you can add the lines

> >              PATH=c:\DevCpp\bin;%PATH%
> >              set MINGDIR=c:\DevCpp

> to your '`c:\autoexec.bat`' file and reboot. If you use Windows ME, you can run '`msconfig`', select the 'Environment' tab, then modify `PATH` and add `MINGDIR`. If you use Windows NT/2k/XP, you can open the Control Panel, click the 'System' applet, the 'Advanced' tab and finally the 'Environment' button, then modify `PATH` and add `MINGDIR`.

Test the installation by typing the following on the command line: '`gcc -v`'. The answer should be similar to:

>           Reading specs from ../lib/gcc-lib/mingw32/3.2/specs
>           Configured with: ../gcc/configure --with-gcc --with-gnu-ld
>           --with-gnu-as --host=mingw32 --target=mingw32 --prefix=/mingw
>           --enable-threads --disable-nls --enable-languages=f77,c++,objc,ada
>           --disable-win32-registry --disable-shared
>           Thread model: win32
>           gcc version 3.2 (mingw special 20020817-1)

If you don't know how to open a terminal, you can click on '`Start -> Run`' then type "`command`". Under Windows 2k/XP, you should type "`cmd`" instead.

# Setting up Cygwin to build Allegro

Note: Allegro 4.4 has not been tested with Cygwin yet!

The procedure is as follows:

> 1. Make sure you have a working Cygwin installation. You can download the `setup.exe` program from 'http://sources.redhat.com/cygwin/'. You will need the following packages: bash, binutils, coreutils, cygwin, cygutils, fileutils, gcc, gdb, login, make, man, mingw-runtime, sed, texinfo and w32api.

> 2. Get the minimal DirectX 7 SDK for MinGW. (`dx70_mgw.zip`) Download it from 'http://alleg.sourceforge.net/wip.html' and unzip it to a temporary directory, for instance '`C:\Temp`'. Then move the contents of '`C:\Temp\lib`' to '`C:\cygwin\lib\w32api`', and the contents of '`C:\Temp\include`' to '`c:\cygwin\usr\include\w32api`'. If you are asked if you want to overwrite any existing files, choose to overwrite them.

> 3. Put the following text in '`/etc/profile`' (`c:\cygwin\etc\profile`)

> >              export ALLEGRO_USE_CYGWIN=1
> >              export MINGDIR=/usr/local
> >              export CPATH=/usr/local/include
> >              export LIBRARY_PATH=/usr/local/lib

> Note: if the `CPATH` or `LIBRARY_PATH` variables are already set, you will have to append the new path to the existing one by using a colon (":") as the separator.

Test the installation by typing the following in the Bash shell: '`gcc -v`'. The answer should be similar to:

>           Reading specs from /usr/lib/gcc-lib/i686-pc-cygwin/3.2/specs
>           gcc version 3.2 20020927 (prerelease)

Note: if you have problems installing the profiling version of the Allegro library, you will probably need to copy a file called `libgmon.a` from the MinGW distribution to your `/lib/mingw` directory (`c:\cygwin\lib\mingw`) in Cygwin. This is expected to be fixed in a later release of the mingw-runtime package (I'm currently using mingw-runtime-1.2-1).

# Cross compilation

The procedure is as follows:

> 1. Download and install the MinGW cross-compiler. You can get the software:

> - directly from the MingW site: http://sourceforge.net/projects/mingw/. You need the following packages (as of February 2003):
>   - gcc (`gcc-3.2.2-20030208-1-src.tar.gz`)
>   - binutils (`binutils-2.13.90-20030111-1-src.tar.gz`)
>   - mingw runtime (`mingw-runtime-2.4.tar.gz`)
>   - w32api (`w32api-2.2.tar.gz`)
>   Optionally, you can get from the SDL site, http://www.libsdl.org/extras/win32/common: opengl-devel (`opengl-devel.tar.gz`)
> - using a more convenient script with instructions for downloading: http://www.libsdl.org/extras/win32/cross/README.txt. Follow the instructions, and make sure to edit the build-crosh.sh script so it downloads the most recent version of gcc and binutils.
> - as a premade Debian package called '`mingw32`', which you can install with '`apt-get install mingw32`'.
> 2. Get the minimal DirectX 7 SDK for MinGW (`dx70_mgw.zip`). Download it from 'http://alleg.sourceforge.net/wip.html' and unzip it in the cross-compiler base directory. Make sure you convert all text files to unix style (`unzip -a`) or the preprocessor will croak. The DirectX package downloaded and installed by the SDL script is not up to date: replace it with the package from the Allegro site.

> 3. Use the cmake/Toolchain-mingw.cmake file.

# Installing Allegro

Once your compiler is set up, follow the generic build instructions in docs/build/cmake.txt.

# Using Allegro

All the Allegro functions, variables, and data structures are defined in `allegro.h`. You should include this in your programs, and link with either the optimised library `liballeg.a`, the debugging library `liballeg-debug.a`, or the profiling library `liballeg-profile.a`. You should include the Allegro DLLs in any software you release to the public.

When using a statically linked library, you must define the preprocessor symbol `ALLEGRO_STATICLINK` before including any of the Allegro headers and link your program against Allegro and the main Win32/DirectX libraries in that order. The names of the statically linked Allegro libraries are post-fixed with '`-static`' so that you will link with either `liballeg-static.a`, `liballeg-debug-static.a` or `liballeg-profile-static.a`.

Don't forget that you need to use the `END_OF_MAIN()` macro right after your `main()` function.

# Compiling manually with MinGW

A simple example of a command line to compile an Allegro program with MinGW looks like:

>           gcc foo.c -Wl,--subsystem,windows -O2 -Wall -o foo.exe -lalleg

If you are compiling with Cygwin, the compiler option '`-mno-cygwin`' must be added, both at compile-time and at link-time:

>           gcc foo.c -Wl,--subsystem,windows -mno-cygwin -O2 -Wall -o foo.exe -lalleg

Note that, if you want to make a console application, you must use '`-Wl,--subsystem,console`' instead of '`-Wl,--subsystem,windows`'.

# Creating a program with Dev-C++

A simple example on how to create a little program with Dev-C++:

Launch Dev-C++ and create a new project (File/New Project). Select "Windows Application", then click on the "Ok" button. Name your project and give associate it to a new file. You should now see a sample code in a window. Close that window since you won't be needing it (Allegro is much simpler to use than this). Create a new file (File/New Source File), then write a small Allegro program. You can inspire yourself by the Allegro examples if you wish. Here's a small program you can type to see if everything worked until now:

>           #include <allegro.h>

>           int main() {
>              allegro_init();
>              allegro_message("Hello World!");
>              return 0;
>           }
>           END_OF_MAIN()

You now need to tell Dev-C++ that you'd like to make a program that uses Allegro. For that, go in the Project Options screen (Project/Project Options menu), then enter `-lalleg` (or `-lalld` for the debug mode) in the box under 'Further object file or linker options' or select 'Parameters tab' and enter -lalleg (or -lalld for the debug mode) in the box under 'Linker'.

Compile your project! Simply click on the green check mark on your Dev-C++ toolbar. Correct any syntax errors in your code, then click on "Execute" to run the program. If all worked you will see a message box pop up with "Hello World" inside of it.

Happy coding!