Some build tweaks for standalone C++ programs (#13)

* Make standalone programs each a separate Makefile target

This enabled parallel builds as well as separates dependencies.

* Add missing header dependencies to standalone targets

* Make it easy to choose C++ compiler and pass flags to it and linker

* Compile standalone C++ programs into source tree root instead of one level higher

Makefile

@@ -6,6 +6,7 @@ VERSION=2.2
 BUILDIR=$(CURDIR)/debian/$(PROJECT)
 SRCDIR=$(CURDIR)/src
 MULTIPREC=100
+CXX_NMIE_HEADERS=$(SRCDIR)/nmie.hpp $(SRCDIR)/nmie-impl.hpp $(SRCDIR)/nmie-precision.hpp
 
 all:
 	@echo "make source - Create source package for Python extension"
@@ -50,13 +51,18 @@ builddeb:
 	# build the package
 	dpkg-buildpackage -i -I -rfakeroot
 
-standalone: $(SRCDIR)/farfield.cc $(SRCDIR)/nearfield.cc $(SRCDIR)/nmie.cc
-    # create standalone programs with DP
-	c++ -DNDEBUG -O2 -Wall -std=c++11 $(SRCDIR)/farfield.cc $(SRCDIR)/nmie.cc  -lm -o ../scattnlay
-	c++ -DNDEBUG -O2 -Wall -std=c++11 $(SRCDIR)/nearfield.cc $(SRCDIR)/nmie.cc  -lm -o ../fieldnlay
-	# create standalone programs with MP
-	c++ -DNDEBUG -DMULTI_PRECISION=$(MULTIPREC) -O2 -Wall -std=c++11 $(SRCDIR)/farfield.cc $(SRCDIR)/nmie.cc  -lm -o ../scattnlay-mp
-	c++ -DNDEBUG -DMULTI_PRECISION=$(MULTIPREC) -O2 -Wall -std=c++11 $(SRCDIR)/nearfield.cc $(SRCDIR)/nmie.cc  -lm -o ../fieldnlay-mp
+standalone: scattnlay fieldnlay scattnlay-mp fieldnlay-mp
+
+# standalone programs with DP
+scattnlay: $(SRCDIR)/farfield.cc $(SRCDIR)/nmie.cc $(CXX_NMIE_HEADERS)
+	$(CXX) -DNDEBUG -O2 -Wall -std=c++11 $(SRCDIR)/farfield.cc $(SRCDIR)/nmie.cc  -lm -o scattnlay $(CXXFLAGS) $(LDFLAGS)
+fieldnlay: $(SRCDIR)/nearfield.cc $(SRCDIR)/nmie.cc $(CXX_NMIE_HEADERS)
+	$(CXX) -DNDEBUG -O2 -Wall -std=c++11 $(SRCDIR)/nearfield.cc $(SRCDIR)/nmie.cc  -lm -o fieldnlay $(CXXFLAGS) $(LDFLAGS)
+# standalone programs with MP
+scattnlay-mp: $(SRCDIR)/farfield.cc $(SRCDIR)/nmie.cc $(CXX_NMIE_HEADERS)
+	$(CXX) -DNDEBUG -DMULTI_PRECISION=$(MULTIPREC) -O2 -Wall -std=c++11 $(SRCDIR)/farfield.cc $(SRCDIR)/nmie.cc  -lm -o scattnlay-mp $(CXXFLAGS) $(LDFLAGS)
+fieldnlay-mp: $(SRCDIR)/nearfield.cc $(SRCDIR)/nmie.cc $(CXX_NMIE_HEADERS)
+	$(CXX) -DNDEBUG -DMULTI_PRECISION=$(MULTIPREC) -O2 -Wall -std=c++11 $(SRCDIR)/nearfield.cc $(SRCDIR)/nmie.cc  -lm -o fieldnlay-mp $(CXXFLAGS) $(LDFLAGS)
 
 clean:
 	$(PYTHON) setup.py clean