libvips/m4/webp.m4

120 lines
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dnl From FIND_MOTIF and ACX_PTHREAD, without much understanding
dnl
dnl FIND_LIBWEBP[ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]]
dnl ---------------------------------------------------
dnl
dnl Find webp libraries and headers ... useful for platforms which are missing
dnl the webp .pc file
dnl
dnl Put compile stuff in LIBWEBP_INCLUDES
dnl Put link stuff in LIBWEBP_LIBS
dnl Define HAVE_LIBWEBP if found.
dnl
AC_DEFUN([FIND_LIBWEBP], [
AC_REQUIRE([AC_PATH_XTRA])
LIBWEBP_INCLUDES=""
LIBWEBP_LIBS=""
AC_ARG_WITH(libwebp,
AS_HELP_STRING([--without-libwebp], [build without libwebp (default: test)]))
# Treat --without-libwebp like --without-libwebp-includes --without-libwebp-libraries.
if test "$with_libwebp" = "no"; then
LIBWEBP_INCLUDES=no
LIBWEBP_LIBS=no
fi
AC_ARG_WITH(libwebp-includes,
AS_HELP_STRING([--with-libwebp-includes=DIR], [libwebp includes are in DIR]),
LIBWEBP_INCLUDES="-I$withval")
AC_ARG_WITH(libwebp-libraries,
AS_HELP_STRING([--with-libwebp-libraries=DIR], [libwebp libraries are in DIR]),
LIBWEBP_LIBS="-L$withval -lwebp")
AC_MSG_CHECKING(for libwebp)
# Look for webp/decode.h
if test "$LIBWEBP_INCLUDES" = ""; then
# Check the standard search path
AC_TRY_COMPILE([#include <webp/decode.h>],[int a;],[
LIBWEBP_INCLUDES=""
], [
# webp/decode.h is not in the standard search path, try
# $prefix
libwebp_save_INCLUDES="$INCLUDES"
INCLUDES="-I${prefix}/include $INCLUDES"
AC_TRY_COMPILE([#include <webp/decode.h>],[int a;],[
LIBWEBP_INCLUDES="-I${prefix}/include"
], [
LIBWEBP_INCLUDES="no"
])
INCLUDES=$libwebp_save_INCLUDES
])
fi
# Now for the libraries
if test "$LIBWEBP_LIBS" = ""; then
libwebp_save_LIBS="$LIBS"
libwebp_save_INCLUDES="$INCLUDES"
LIBS="-lwebp $LIBS"
INCLUDES="$LIBWEBP_INCLUDES $INCLUDES"
# Try the standard search path first
AC_TRY_LINK([#include <webp/decode.h>],[WebPInitDecoderConfig(0)], [
LIBWEBP_LIBS="-lwebp"
], [
# libwebp is not in the standard search path, try $prefix
LIBS="-L${prefix}/lib $LIBS"
AC_TRY_LINK([#include <webp/decode.h>],[WebPInitDecoderConfig(0)], [
LIBWEBP_LIBS="-L${prefix}/lib -lwebp"
], [
LIBWEBP_LIBS=no
])
])
LIBS="$libwebp_save_LIBS"
INCLUDES="$libwebp_save_INCLUDES"
fi
AC_SUBST(LIBWEBP_LIBS)
AC_SUBST(LIBWEBP_INCLUDES)
# Print a helpful message
libwebp_libraries_result="$LIBWEBP_LIBS"
libwebp_includes_result="$LIBWEBP_INCLUDES"
if test x"$libwebp_libraries_result" = x""; then
libwebp_libraries_result="in default path"
fi
if test x"$libwebp_includes_result" = x""; then
libwebp_includes_result="in default path"
fi
if test "$libwebp_libraries_result" = "no"; then
libwebp_libraries_result="(none)"
fi
if test "$libwebp_includes_result" = "no"; then
libwebp_includes_result="(none)"
fi
AC_MSG_RESULT([libraries $libwebp_libraries_result, headers $libwebp_includes_result])
# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
if test "$LIBWEBP_INCLUDES" != "no" && test "$LIBWEBP_LIBS" != "no"; then
AC_DEFINE(HAVE_LIBWEBP,1,[Define if you have libwebp libraries and header files.])
$1
else
LIBWEBP_INCLUDES=""
LIBWEBP_LIBS=""
$2
fi
])dnl