Cleaned up makefile

Makefile

@@ -22,22 +22,31 @@ libs: $(BUILD_DIR)/hid.o
 # Flags and autodetection
 
 # -MMD and -MP generate makefiles with extension .d.
-CPPFLAGS := -Wall -MMD -MP -I src -I libs/hidapi/hidapi
+CPPFLAGS := -MMD -MP \
+	-Wall \
+	-I src \
+	-I libs/hidapi/hidapi
+
+# udev: required by hidapi
 LDFLAGS := -l fftw3 -l udev
 
 # Find all cpp files in source dirs
 SRCS := $(shell find $(SRC_DIRS) -name '*.cpp')
-# Turns ./build/a.cpp into ./build/a.cpp.o
-OBJS := $(SRCS:%=$(BUILD_DIR)/%.o)
+# Turns src/a.cpp into build/src/a.cpp.o
+SRC_OBJS := $(SRCS:%=$(BUILD_DIR)/%.o)
 LIB_OBJS := $(BUILD_DIR)/hid.o
-# Turns ./build/a.cpp.o into ./build/a.cpp.d
+OBJS = $(SRC_OBJS) $(LIB_OBJS)
+# Turns build/a.cpp.o into build/a.cpp.d
 DEPS := $(OBJS:.o=.d)
 
 #################################################
 # Build targets
 
-HIDAPI_PATH := libs/hidapi
+
+### Libraries
+
 # Build hidapi
+HIDAPI_PATH := libs/hidapi
 $(BUILD_DIR)/hid.o:
 	@mkdir -p $(BUILD_DIR)
 
@@ -49,15 +58,18 @@ $(BUILD_DIR)/hid.o:
 		$(HIDAPI_PATH)/linux/hid.c \
 		-o $(BUILD_DIR)/hid.o
 
+
+### Source
+
 # C++ build step
-$(BUILD_DIR)/%.cpp.o: %.cpp $(BUILD_DIR)/hid.o
+$(BUILD_DIR)/%.cpp.o: %.cpp
 	mkdir -p $(dir $@)
 	g++ $(CPPFLAGS) $(CXXFLAGS) -c $< -o $@
 
 
 # Final build step
 $(TARGET_EXEC) : $(OBJS)
-	g++ $(OBJS) $(LIB_OBJS) -o $@ $(LDFLAGS)
+	g++ $(OBJS) -o $@ $(LDFLAGS)