Modified the Linux build system so that makefiles are now outside the source tree

git-svn-id: https://sfml.svn.sourceforge.net/svnroot/sfml/branches/sfml2@1477 4e206d99-4929-0410-ac5d-dfc041789085

samples/build/make/Makefile.opengl

@@ -0,0 +1,21 @@
+EXE     = opengl
+SRC     = $(wildcard $(SRCROOT)/$(EXE)/*.cpp)
+OBJ     = $(SRC:.cpp=.o)
+LDFLAGS = -lsfml-graphics -lsfml-window -lsfml-system -lGLU -lGL
+
+all: $(EXE)
+
+$(EXE): $(OBJ)
+	$(CPP) -o $(BINPATH)/$(EXE) $(OBJ) $(LDFLAGS)
+
+$(OBJ): %.o: %.cpp
+	$(CPP) -o $@ -c $< $(CFLAGS)
+
+.PHONY: clean mrproper
+
+clean:
+	@rm -rf $(OBJ)
+
+mrproper: clean
+	@rm -rf $(BINPATH)/$(EXE)
+