clean up example Makefile

examples/Makefile

@@ -13,31 +13,25 @@ LDFLAGS = -lSDL2 -lGLEW -lGL
 ASSIMP_LIB := ../$(ASSIMP_DIR)/build/code/libassimp.a
 endif
 
+EXAMPLE_SOURCES = \
+	hello_world/main.cpp \
+	assimp_loading/main.cpp \
+	simple_mesh/main.cpp \
+EXAMPLE_OBJECTS = $(patsubst %/, $(OBJDIR)/%.o, $(dir $(EXAMPLE_SOURCES)))
 
-all: mkdirs \
-	$(OBJDIR)/hello_world.o \
-	$(OBJDIR)/assimp_loading.o \
-	$(OBJDIR)/simple_mesh.o
-.PHONY: all
+all: mkdirs $(EXAMPLE_OBJECTS)
 
 -include $(OBJDIR)/*.d
 
+$(EXAMPLE_OBJECTS):
+	$(CXX) $(CXXFLAGS) -c -MMD $(basename $(notdir $@))/main.cpp -o $@
+	$(CXX) -o $(BINDIR)/$(notdir $(basename $@)) $(LDFLAGS) $@ $(LIB) \
+		$(ASSIMP_LIB)
+
 mkdirs:
-	mkdir -p $(BINDIR) $(OBJDIR)
+	@mkdir -p $(BINDIR) $(OBJDIR)
 .PHONY: mkdirs
 
-$(OBJDIR)/hello_world.o: $(LIB)
-	$(CXX) $(CXXFLAGS) -c -MMD hello_world/main.cpp -o $@
-	$(CXX) -o $(BINDIR)/hello_world $(LDFLAGS) $@ $(LIB) $(ASSIMP_LIB)
-
-$(OBJDIR)/assimp_loading.o: $(LIB)
-	$(CXX) $(CXXFLAGS) -c -MMD assimp_loading/main.cpp -o $@
-	$(CXX) -o $(BINDIR)/assimp_loading $(LDFLAGS) $@ $(LIB) $(ASSIMP_LIB)
-
-$(OBJDIR)/simple_mesh.o: $(LIB)
-	$(CXX) $(CXXFLAGS) -c -MMD simple_mesh/main.cpp -o $@
-	$(CXX) -o $(BINDIR)/simple_mesh $(LDFLAGS) $@ $(LIB) $(ASSIMP_LIB)
-
 clean:
 	rm -rf $(OBJDIR)/* bin/*
 .PHONY: clean