Added Freedoom plus dependency and three engines to run it. Based on Arch Linux PKGBUILD files.

deutex-dev/PKGBUILD

+#
+# Games Packages for Chakra, part of chakra-project.org
+#
+# Maintainer: Adrián Chaves Fernández (Gallaecio) <adriyetichaves gmail.com>
+
+pkgname=deutex-dev
+_pkgname=deutex
+pkgver=4.4.902
+pkgrel=1
+pkgdesc="A WAD file composer for Doom, Heretic, Hexen and Strife."
+arch=('i686' 'x86_64')
+url="http://www.teaser.fr/~amajorel/deutex/"
+license=('custom:GPL, LGPL and Pbmplus license')
+provides=('deutex')
+conflicts=('deutex')
+source=(http://www.teaser.fr/~amajorel/$_pkgname/fungus/$_pkgname-$pkgver.tar.gz)
+md5sums=('5f2d6184b69e2e05f4e7c5bcd6a74cb9')
+
+build() {
+    cd $srcdir/$_pkgname-$pkgver
+
+    ./configure \
+      --cflags="$CFLAGS"
+
+    make
+}
+
+package() {
+    cd $srcdir/$_pkgname-$pkgver
+
+    install -d $pkgdir/usr/{bin,share/man/man6}
+
+    make \
+      BINDIR=$pkgdir/usr/bin \
+      MANDIR=$pkgdir/usr/share/man \
+      install
+
+    # License.
+    install -Dm 644 LICENCE $pkgdir/usr/share/licenses/$pkgname/LICENSE
+}

freedoom/PKGBUILD

+#
+# Games Packages for Chakra, part of chakra-project.org
+#
+# Maintainer: Adrián Chaves Fernández (Gallaecio) <adriyetichaves gmail.com>
+
+pkgname=freedoom
+_pkgname=doom
+pkgver=0.7
+pkgrel=1
+pkgdesc="Completely free Doom IWADs (game data)"
+arch=('any')
+url="http://www.nongnu.org/freedoom/"
+license=('custom:Modified BSD')
+makedepends=('deutex' 'imagemagick' 'python2')
+provides=('doom-data')
+source=(http://savannah.nongnu.org/download/$pkgname/source/$pkgname-$pkgver.tar.gz)
+md5sums=('109b1a10a13cfa9c72f9096f4a0ef0cd')
+
+build() {
+  cd $srcdir/$pkgname-$pkgver
+
+  make wads/{doom,doom2,freedm}.wad
+}
+
+package() {
+  cd $srcdir/$pkgname-$pkgver
+
+  install -d $pkgdir/usr/share/$_pkgname
+  install -m644 wads/{doom,doom2,freedm}.wad $pkgdir/usr/share/$_pkgname/
+
+  # License.
+  install -Dm644 COPYING $pkgdir/usr/share/licenses/$pkgname/COPYING
+}

odamex/PKGBUILD

+#
+# Games Packages for Chakra, part of chakra-project.org
+#
+# Maintainer: Adrián Chaves Fernández (Gallaecio) <adriyetichaves gmail.com>
+
+pkgname=odamex
+pkgver=0.5.3
+pkgrel=1
+pkgdesc='A free client/server multiplayer engine for the classic FPS Doom.'
+arch=('i686' 'x86_64')
+url='http://odamex.net/'
+license=('GPL')
+depends=('sdl_mixer>=1.2.6')
+provides=('doom')
+source=("http://downloads.sourceforge.net/$pkgname/$pkgname-src-$pkgver.tar.bz2")
+md5sums=('8779b0b5ab6d4c15f0e05cd4b250c886')
+
+build() {
+  cd $srcdir/$pkgname-src-$pkgver
+
+  sed 's|getenv("DOOMWADPATH")|"/usr/share/doom"|g' -i {client,server}/src/d_main.cpp
+
+  make CFLAGS="${CXXFLAGS} -DUNIX -DLINUX -DNOASM -Icommon" odamex odasrv
+}
+
+package() {
+  cd $srcdir/$pkgname-src-$pkgver
+
+  install -Dm755 odamex $pkgdir/usr/bin/odamex
+  install -Dm755 odasrv $pkgdir/usr/bin/odasrv
+  install -Dm644 odamex.wad $pkgdir/usr/share/doom/odamex.wad
+  install -Dm644 media/icon_odamex_96.png $pkgdir/usr/share/pixmaps/odamex.png
+  install -Dm644 media/icon_odasrv_96.png $pkgdir/usr/share/pixmaps/odasrv.png
+  install -Dm644 installer/arch/odamex.desktop $pkgdir/usr/share/applications/odamex.desktop
+  install -Dm644 installer/arch/odasrv.desktop $pkgdir/usr/share/applications/odasrv.desktop
+}

prboom/PKGBUILD

+#
+# Games Packages for Chakra, part of chakra-project.org
+#
+# Maintainer: Adrián Chaves Fernández (Gallaecio) <adriyetichaves gmail.com>
+
+pkgname=prboom
+pkgver=2.5.0
+pkgrel=1
+pkgdesc="A game engine which provides a program to play Doom levels."
+url="http://prboom.sourceforge.net/"
+license=('GPL2')
+arch=('i686' 'x86_64')
+depends=('libpng' 'mesa' 'sdl_mixer' 'sdl_net')
+provides=('doom')
+source=("http://downloads.sourceforge.net/prboom/$pkgname-$pkgver.tar.gz"
+	'libpng-1.4.patch')
+md5sums=('a8a15f61fa2626ab98051ab2703378c4'
+	 'ba53474db8e747035ca2320a445e4ae0')
+
+build() {
+  cd $srcdir/$pkgname-$pkgver
+
+  msg "Patching…"
+
+  patch -p1 < ../libpng-1.4.patch
+
+  msg "Building…"
+
+  ./configure \
+    --prefix=/usr \
+    --disable-i386-asm
+
+  sed -i "s|/games|/bin|g" $srcdir/$pkgname-$pkgver/src/Makefile
+
+  make
+}
+
+package() {
+  cd $srcdir/$pkgname-$pkgver
+
+  make DESTDIR=$pkgdir install
+}
+

prboom/libpng-1.4.patch

+diff -Naur prboom-2.5.0-orig/src/SDL/i_sshot.c prboom-2.5.0/src/SDL/i_sshot.c
+--- prboom-2.5.0-orig/src/SDL/i_sshot.c	2010-01-24 23:26:03.000000000 -0500
++++ prboom-2.5.0/src/SDL/i_sshot.c	2010-01-24 23:28:42.000000000 -0500
+@@ -231,7 +231,7 @@
+   if (fp)
+   {
+     png_struct *png_ptr = png_create_write_struct(
+-        PNG_LIBPNG_VER_STRING, png_error_ptr_NULL, error_fn, warning_fn);
++        PNG_LIBPNG_VER_STRING, NULL, error_fn, warning_fn);
+ 
+     if (png_ptr)
+     {
+@@ -279,7 +279,7 @@
+             break;
+         }
+       }
+-      png_destroy_write_struct(&png_ptr,  png_infopp_NULL);
++      png_destroy_write_struct(&png_ptr,  NULL);
+     }
+     fclose(fp);
+   }

remood/PKGBUILD

+#
+# Games Packages for Chakra, part of chakra-project.org
+#
+# Maintainer: Adrián Chaves Fernández (Gallaecio) <adriyetichaves gmail.com>
+
+pkgname=remood
+_pkgname=doom
+pkgver=0.8a
+_pkgver=08a
+pkgrel=1
+pkgdesc="An advanced Doom game engine based on Doom Legacy."
+arch=('i686' 'x86_64')
+url="http://$pkgname.sourceforge.net/"
+license=('GPL')
+depends=('bash' 'sdl')
+provides=('doom')
+source=(http://downloads.sourceforge.net/$pkgname/${pkgname}src_$_pkgver.tar.gz)
+md5sums=('33e284a22467e732cbdad4d17e03a648')
+
+build() {
+  cd ${pkgname}src_$_pkgver
+
+  make CC_MODECFLAGS="$CFLAGS -DNDEBUG"
+}
+
+package() {
+  cd ${pkgname}src_$_pkgver
+
+  mkdir -p $pkgdir/usr/share/{applications,pixmaps,$pkgname}
+  install -Dm755	bin/$pkgname		$pkgdir/usr/share/$pkgname/
+  install -m644		bin/$pkgname.wad	$pkgdir/usr/share/$pkgname/
+  install -m644		$pkgname.xpm		$pkgdir/usr/share/pixmaps/
+  install -m644		$pkgname.desktop	$pkgdir/usr/share/applications/
+
+  mkdir -p $pkgdir/usr/bin
+  echo "#!/bin/sh"	 > $pkgdir/usr/bin/$pkgname
+  echo "DOOMWADDIR=\"/usr/share/$_pkgname:/usr/share/$pkgname\" exec /usr/share/$pkgname/$pkgname \$@" \
+			>> $pkgdir/usr/bin/$pkgname
+  chmod +x $pkgdir/usr/bin/$pkgname
+}