TARGET_EXEC := test
BUILD_DIR := ./build
SRC_DIRS := ./src

# False targets
# (these are the only ones you manually run)
all: $(TARGET_EXEC)

run: all
	./$(TARGET_EXEC)

clean:
	-rm -r $(BUILD_DIR)
	@echo ""


libs: $(BUILD_DIR)/hid.o

.PHONY: clean all run libs

#################################################
# Flags and autodetection

# -MMD and -MP generate makefiles with extension .d.
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 src/a.cpp into build/src/a.cpp.o
SRC_OBJS := $(SRCS:%=$(BUILD_DIR)/%.o)
LIB_OBJS := $(BUILD_DIR)/hid.o
OBJS = $(SRC_OBJS) $(LIB_OBJS)
# Turns build/a.cpp.o into build/a.cpp.d
DEPS := $(OBJS:.o=.d)

#################################################
# Build targets


### Libraries

# Build hidapi
HIDAPI_PATH := libs/hidapi
$(BUILD_DIR)/hid.o:
	@mkdir -p $(BUILD_DIR)

	@echo "Compiling hid.o"
	@gcc -Wall -g -fpic -c \
		-I $(HIDAPI_PATH)/hidapi \
		`pkg-config libusb-1.0 --cflags` \
		\
		$(HIDAPI_PATH)/linux/hid.c \
		-o $(BUILD_DIR)/hid.o


### Source

# C++ build step
$(BUILD_DIR)/%.cpp.o: %.cpp
	mkdir -p $(dir $@)
	g++ $(CPPFLAGS) $(CXXFLAGS) -c $< -o $@


# Final build step
$(TARGET_EXEC) : $(OBJS)
	g++ $(OBJS) -o $@ $(LDFLAGS)



# Include generated makefiles
-include $(DEPS)