restructure for makefile

Makefile

@@ -24,15 +24,12 @@ INC_FLAGS := $(addprefix -I,$(INC_DIRS))
 # The -MMD and -MP flags together generate Makefiles for us!
 CPPFLAGS := $(INC_FLAGS) -MMD -MP
 
-
-
 # The final build step.
 $(BUILD_DIR)/$(TARGET_EXEC): $(OBJS)
 	$(CXX) $(OBJS) -o $@ $(LDFLAGS)
 
 # Build step for C++ source
-$(BUILD_DIR)/%.cpp.o: %.cpp $(SPIRVS) .simdb
-    mkdir -p $(dir $@)
+$(BUILD_DIR)/%.cpp.o: %.cpp .simdb $(SPIRVS)
     $(CXX) $(CPPFLAGS) $(CXXFLAGS) -c $< -o $i@
 
 #build the shaders
@@ -40,6 +37,5 @@ $(SPIRVS): $(GLSL)
     mkdir -p $(dir $@)
     glslc $(shaders).glsl $(shaders).spv
 
-
 run: $(BUILD_DIR)/$(TARGET_EXEC)
     ./$(BUILD_DIR)/$(TARGET_EXEC)