Added native and emulated S3TC support.

diff --git a/configure b/configure
index b6eb400..69c9945 100755
--- a/configure
+++ b/configure
@@ -15272,6 +15272,80 @@
 _ACEOF
 fi
 
+echo "$as_me:$LINENO: checking for -ltxc_dxtn soname" >&5
+echo $ECHO_N "checking for -ltxc_dxtn soname... $ECHO_C" >&6
+if test "${ac_cv_lib_soname_txc_dxtn+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  ac_get_soname_save_LIBS=$LIBS
+LIBS="-ltxc_dxtn  $LIBS"
+  cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+
+/* Override any gcc2 internal prototype to avoid an error.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+/* We use char because int might match the return type of a gcc2
+   builtin and then its argument prototype would still apply.  */
+char fetch_2d_texel_rgba_dxt1 ();
+int
+main ()
+{
+fetch_2d_texel_rgba_dxt1 ();
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext conftest$ac_exeext
+if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5
+  (eval $ac_link) 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } &&
+	 { ac_try='test -z "$ac_c_werror_flag"			 || test ! -s conftest.err'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; } &&
+	 { ac_try='test -s conftest$ac_exeext'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  ac_cv_lib_soname_txc_dxtn=`$ac_cv_path_LDD conftest$ac_exeext | grep libtxc_dxtn\\.$LIBEXT | sed "s/^.*\(libtxc_dxtn\.$LIBEXT[^	 ]*\).*$/\1/"`
+  if test "x$ac_cv_lib_soname_txc_dxtn" = "x"
+  then
+     ac_cv_lib_soname_txc_dxtn="libtxc_dxtn.$LIBEXT"
+  fi
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+ac_cv_lib_soname_txc_dxtn="libtxc_dxtn.$LIBEXT"
+fi
+rm -f conftest.err conftest.$ac_objext \
+      conftest$ac_exeext conftest.$ac_ext
+  LIBS=$ac_get_soname_save_LIBS
+fi
+echo "$as_me:$LINENO: result: $ac_cv_lib_soname_txc_dxtn" >&5
+echo "${ECHO_T}$ac_cv_lib_soname_txc_dxtn" >&6
+if test "x$ac_cv_lib_soname_txc_dxtn" != xNONE
+then
+cat >>confdefs.h <<_ACEOF
+#define SONAME_LIBTXC_DXTN "$ac_cv_lib_soname_txc_dxtn"
+_ACEOF
+fi
+
 echo "$as_me:$LINENO: checking for -lcups soname" >&5
 echo $ECHO_N "checking for -lcups soname... $ECHO_C" >&6
 if test "${ac_cv_lib_soname_cups+set}" = set; then