Makefile

# Thanks to Job Vranish (https://spin.atomicobject.com/2016/08/26/makefile-c-projects/)
TARGET_EXEC := dark_scrolls 

BUILD_DIR := ./build
DATA_DIR := ./data
SRC_DIRS := ./src

# Find all the C and C++ files we want to compile
# Note the single quotes around the * expressions. Make will incorrectly expand these otherwise.
SRCS := $(shell find $(SRC_DIRS) -name '*.cpp' -or -name '*.c' -or -name '*.s')
HEADERS := $(shell find $(SRC_DIRS) -name '*.hpp' -or -name '*.h')

# String substitution for every C/C++ file.
# As an example, hello.cpp turns into ./build/hello.cpp.o
OBJS := $(SRCS:%=$(BUILD_DIR)/%.o)

# String substitution (suffix version without %).
# As an example, ./build/hello.cpp.o turns into ./build/hello.cpp.d
DEPS := $(OBJS:.o=.d)

# Every folder in ./src will need to be passed to GCC so that it can find header files
INC_DIRS := $(shell find $(SRC_DIRS) -type d)
INC_DIRS := third_party/json
# Add a prefix to INC_DIRS. So moduleA would become -ImoduleA. GCC understands this -I flag
INC_FLAGS := $(addprefix -I,$(INC_DIRS))

# The -MMD and -MP flags together generate Makefiles for us!
# These files will have .d instead of .o as the output.
CPPFLAGS += $(INC_FLAGS) -MMD -MP

OSCFLAGS :=
OSLDFLAGS :=
EXENAME :=
ifeq ($(OS),Windows_NT)
	OSCFLAGS += -DDARK_SCROLLS_WINDOWS -Dmain=SDL_main
	OSLDFLAGS += -lmingw32 -mwindows -lSDL2main
	EXENAME += dark_scrolls.exe
else
	OSCFLAGS += -DDARK_SCROLLS_LINUX
	EXENAME += dark_scrolls
endif

CFLAGS += $(OSCFLAGS) -Wall
LDFLAGS += $(OSLDFLAGS) -lSDL2 -lSDL2_ttf -lSDL2_image -lSDL2_mixer

ifeq ($(OPTIMIZE),1)
	CFLAGS += -O3 -flto
	LDFLAGS += -flto
else ifeq ($(OPTIMIZE),DEBUG)
	CFLAGS += -O3 -g -flto
	LDFLAGS += -flto
else
	CFLAGS += -g
endif

CXXFLAGS += $(CFLAGS) --std=c++17

# The final build step.
$(TARGET_EXEC): $(OBJS)
	$(CXX) $(OBJS) -o $@ $(LDFLAGS)

# Build step for C source
$(BUILD_DIR)/%.c.o: %.cpp
	mkdir -p $(dir $@)
	$(CC) $(CPPFLAGS) $(CFLAGS) -c $< -o $@

# Build step for C++ source
$(BUILD_DIR)/%.cpp.o: %.cpp
	mkdir -p $(dir $@)
	$(CXX) $(CPPFLAGS) $(CXXFLAGS) -c $< -o $@

.PHONY: clean
clean:
	rm -r $(BUILD_DIR)
	rm $(EXENAME)

.PHONY: format
format:
	clang-format --style=LLVM -i $(SRCS) $(HEADERS)

# Include the .d makefiles. The - at the front suppresses the errors of missing
# Makefiles. Initially, all the .d files will be missing, and we don't want those
# errors to show up.
-include $(DEPS)