added configure check for fftw3

[swftools.git] / m4 / fftw.m4

diff --git a/m4/fftw.m4 b/m4/fftw.m4
new file mode 100644 (file)
index 0000000..e26434b
--- /dev/null
+++ b/m4/fftw.m4
@@ -0,0 +1,52 @@
+AC_DEFUN([RFX_CHECK_FFTW],
+[
+  OLDCPPFLAGS="${CPPFLAGS}"
+  OLDLIBS="${LIBS}"
+       
+  AC_CHECK_LIB(fftw3, fftw_plan_dft_r2c_2d, [HAVE_LIBFFTW3=1],)
+  AC_CHECK_HEADERS(fftw3.h,[HAVE_FFTW3_H=1])
+  
+  if test "x${HAVE_LIBFFTW3}" != "x";then
+    if test "x${HAVE_FFTW3_H}" != "x";then
+      HAVE_FFTW3=1
+    fi
+  fi
+  
+  if test "x${HAVE_FFTW3}" = "x1"; then 
+    LIBS="$LIBS -lfftw3"
+    AC_MSG_CHECKING([whether we can compile the fftw3 test program])
+  
+    cat > conftest.c << EOF
+    #include <fftw3.h>
+    
+    int main()
+    {
+       char*data = 0;
+       fftw_plan plan = fftw_plan_dft_2d(600, 800, (fftw_complex*)data, (fftw_complex*)data, FFTW_FORWARD, FFTW_ESTIMATE);
+       plan = fftw_plan_dft_r2c_2d(600, 800, (double*)data, (fftw_complex*)data, FFTW_ESTIMATE);
+       plan = fftw_plan_dft_c2r_2d(600, 800, (fftw_complex*)data, (double*)data, FFTW_ESTIMATE);
+       fftw_execute(plan);
+       fftw_destroy_plan(plan);
+    }
+EOF
+    
+    ac_link='$CC $CPPFLAGS $CFLAGS conftest.c $LDFLAGS $LIBS -o conftest${ac_exeext}'
+    if { (eval echo fftw3.m4:71: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+      AC_MSG_RESULT(yes)
+      AC_DEFINE([HAVE_FFTW3], [1], [Define if fftw3 is available])
+    else
+      echo "configure: failed program was:" >&5
+      cat conftest.c >&5
+      HAVE_FFTW3=0
+      AC_MSG_RESULT(no)
+    fi
+    rm -f conftest*
+  fi
+  
+  # if the above didn't work out, reset all changes to the compiler variables.
+  if test "x${HAVE_FFTW3}" "!=" "x1"; then 
+      CPPFLAGS=$OLDCPPFLAGS
+      LIBS=$OLDLIBS
+  fi 
+])
+