graphics/brlcad: Miscellaneous cleanups and enable libpng patch.

graphics/brlcad/brlcad.SlackBuild

@@ -12,10 +12,19 @@
 
 PRGNAM=brlcad
 VERSION=${VERSION:-7.16.6}
-ARCH=${ARCH:-i486}
 BUILD=${BUILD:-1}
 TAG=${TAG:-_SBo}
 
+# Automatically determine the architecture we're building on:
+if [ -z "$ARCH" ]; then
+  case "$( uname -m )" in
+    i?86) export ARCH=i486 ;;
+    arm*) export ARCH=arm ;;
+    # Unless $ARCH is already set, use uname -m for all other archs:
+       *) export ARCH=$( uname -m ) ;;
+  esac
+fi
+
 CWD=$(pwd)
 TMP=${TMP:-/tmp/SBo}
 PKG=$TMP/package-$PRGNAM
@@ -30,6 +39,9 @@ elif [ "$ARCH" = "i686" ]; then
 elif [ "$ARCH" = "x86_64" ]; then
   SLKCFLAGS="-O2 -fPIC"
   LIBDIRSUFFIX="64"
+else
+  SLKCFLAGS="-O2"
+  LIBDIRSUFFIX=""
 fi
 
 set -e
@@ -55,7 +67,7 @@ patch -p1 < $CWD/patches/gcc433.patch
 # Do not use in 13.0 stable versions (won't work).
 # Newer svn snapshots of brlcad won't need this any longer, but the stable
 #   7.16.6 version still does.
-#patch -p1 < $CWD/patches/libpng14x.patch
+patch -p1 < $CWD/patches/libpng14x.patch
 
 CFLAGS="$SLKCFLAGS" \
 CXXFLAGS="$SLKCFLAGS" \