X-Git-Url: http://git.draconx.ca/gitweb/liblbx.git/blobdiff_plain/f4f10a3e2bd1bd7ffda6462edef92d1d8aaebe2f..a5900574a2d9257695b70ec9a065e4638162e7d6:/m4/libpng.m4

diff --git a/m4/libpng.m4 b/m4/libpng.m4
new file mode 100644
index 0000000..5adeb0f
--- /dev/null
+++ b/m4/libpng.m4
@@ -0,0 +1,109 @@
+dnl Copyright (C) 2009 Nick Bowler
+dnl Copying and distribution of this file, with or without modification,
+dnl are permitted in any medium without royalty provided the copyright
+dnl notice and this notice are preserved.  This file is offered as-is,
+dnl without any warranty.
+
+dnl _LIBPNG_TRY_VERSION(min-version)
+AC_DEFUN([_LIBPNG_TRY_VERSION], [dnl
+sedhead='s/@<:@0-9@:>@@<:@0-9@:>@*/<<<&>>>/'
+sedtail='s/.*<<<\(.*\)>>>.*/\1/;t;s/.*/0/'
+png_min_major=`printf   '%s' '$1' | sed -e "$sedhead"1 -e "$sedtail"`
+png_min_minor=`printf   '%s' '$1' | sed -e "$sedhead"2 -e "$sedtail"`
+png_min_release=`printf '%s' '$1' | sed -e "$sedhead"3 -e "$sedtail"`
+png_min_build=`printf   '%s' '$1' | sed -e "$sedhead"4 -e "$sedtail"`
+png_min_status=`printf  '%s' '$1' | sed '
+	t; s/.*alpha.*/PNG_LIBPNG_BUILD_ALPHA/
+	t; s/.*beta.*/PNG_LIBPNG_BUILD_BETA/
+	t; s/.*rc.*/PNG_LIBPNG_BUILD_RC/
+	t; s/.*/PNG_LIBPNG_BUILD_STABLE/
+'`
+
+AC_CACHE_CHECK([for libpng version at least $1],
+	[libpng_cv_sufficient_ver],
+	[AC_LINK_IFELSE([AC_LANG_PROGRAM([dnl
+#include <png.h>
+#if PNG_LIBPNG_VER_MAJOR < $png_min_major
+#  error Invalid libpng major version
+#elif PNG_LIBPNG_VER_MAJOR == $png_min_major
+#  if PNG_LIBPNG_VER_MINOR < $png_min_minor
+#    error Invalid libpng minor version
+#  elif PNG_LIBPNG_VER_MINOR == $png_min_minor
+#    if PNG_LIBPNG_VER_RELEASE < $png_min_release
+#      error Invalid libpng release
+#    elif PNG_LIBPNG_VER_RELEASE == $png_min_release
+#      if PNG_LIBPNG_BUILD_BASE_TYPE < $png_min_status
+#        error Invalid libpng release status
+#      elif PNG_LIBPNG_BUILD_BASE_TYPE == $png_min_status
+#        if PNG_LIBPNG_VER_BUILD < $png_min_build
+#          error Invalid libpng build
+#        endif
+#      endif
+#    endif
+#  endif
+#endif
+], [dnl
+png_structp png  = png_create_read_struct("", 0, 0, 0);
+png_infop   info = png_create_info_struct(png);
+])], [libpng_cv_sufficient_ver=yes], [libpng_cv_sufficient_ver=no])])
+])
+
+dnl CHECK_LIBPNG([min-version], [action-if-ok], [action-if-fail])
+AC_DEFUN([CHECK_LIBPNG],
+[AC_REQUIRE([PKG_PROG_PKG_CONFIG])dnl
+AC_ARG_VAR([LIBPNG_CFLAGS], [C compiler flags for libpng])dnl
+AC_ARG_VAR([LIBPNG_LIBS],   [linker flags for libpng])dnl
+
+if test x"$PKG_CONFIG" != x; then
+	AC_MSG_CHECKING([pkg-config database for libpng])
+	_PKG_CONFIG([libpng_cflags], [cflags], [libpng])
+	_PKG_CONFIG([libpng_libs],   [libs],   [libpng])
+	if test x$pkg_failed = xyes; then
+		errors=`$PKG_CONFIG --errors-to-stdout --print-errors libpng`
+		echo "$errors" >&AS_MESSAGE_LOG_FD
+		AC_MSG_RESULT([no])
+	else
+		if test x"$LIBPNG_CFLAGS" = x; then
+			LIBPNG_CFLAGS=$pkg_cv_libpng_cflags
+		fi
+		if test x"$LIBPNG_LIBS" = x; then
+			LIBPNG_LIBS=$pkg_cv_libpng_libs
+		fi
+
+		AC_MSG_RESULT([yes])
+	fi
+fi
+
+if test x"$LIBPNG_LIBS" = x; then
+	LIBPNG_LIBS=-lpng
+fi
+
+AC_LANG_PUSH([C])
+old_cflags=$CFLAGS
+old_libs=$LIBS
+CFLAGS="$LIBPNG_CFLAGS $CFLAGS"
+LIBS="$LIBPNG_LIBS $LIBS"
+
+_LIBPNG_TRY_VERSION(ifelse([$1], [], [1.0], [$1]))
+
+CFLAGS=$old_cflags
+LIBS=$old_libs
+AC_LANG_POP([C])
+
+if test x"$libpng_cv_sufficient_ver" = x"yes"; then
+	AC_SUBST([LIBPNG_CFLAGS])
+	AC_SUBST([LIBPNG_LIBS])
+	ifelse([$2], [], [true], [$2])
+else
+	ifelse([$3], [], [AC_MSG_FAILURE([dnl
+libpng version >= ifelse([$1], [], [1.0], [$1]) is required.  The latest
+version can be obtained from http://libpng.org/pub/png/libpng.html.
+
+If libpng is installed but was not found by this configure script,
+consider adjusting LIBPNG_CFLAGS and/or LIBPNG_LIBS as necessary.
+
+If pkg-config is installed, it may help to adjust PKG_CONFIG_PATH
+if libpng is installed in a non-standard prefix.
+])], [$3])
+fi
+])