build: Split out core logic from libpng detection.

[liblbx.git] / configure.ac

diff --git a/configure.ac b/configure.ac
index c03b931b9c32fc7f311ab47b2b1430136c05b1be..f772576636ddb174cad8a84cd3087a43a24882a5 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -17,12 +17,23 @@ AC_PROG_CC_C99
 gl_EARLY
 
 AC_HEADER_ASSERT
-
 LT_INIT
-
 gl_INIT
-
-CHECK_LIBPNG([1.2], [have_libpng=yes], [have_libpng=no])
+PKG_PROG_PKG_CONFIG
+
+AC_ARG_ENABLE([lbximg],
+       [AS_HELP_STRING([--enable-lbximg],
+               [build the lbximg tool (requires libpng) [default=auto]])],
+       [enable_lbximg=$enableval],
+       [enable_lbximg=auto])
+
+have_libpng=no
+if test x"$enable_lbximg" = x"auto"; then
+DX_CHECK_LIBPNG([1.2], [have_libpng=yes], [have_libpng=no])
+fi
+if test x"$enable_lbximg" = x"yes"; then
+DX_CHECK_LIBPNG([1.2], [have_libpng=yes])
+fi
 AM_CONDITIONAL([BUILD_LBXIMG], [test x"$have_libpng" = x"yes"])
 
 # A horrible combination of bugs makes this necessary for GTK+ detection.