COMPILER = gcc

# COMPILER FLAGS
C_FLAG_STD_C99             = -std=c99              # Use the C99 language standard
C_FLAG_DEBUG_INFO          = -g                    # Include debug information
#C_FLAG_HEADERS             = -H                    # Prints paths of all headers
C_FLAG_ALL_WARNINGS        = -Wall                 # Enable most common warning
C_FLAG_PEDANTIC            = -Wpedantic            # Enforce ISO C standard strictly
C_FLAG_SHADOW              = -Wshadow              # Warn if a local variable shadows another
C_FLAG_STRICT_PROTOS       = -Wstrict-prototypes   # Warn if function declarations are missing parameter types
C_FLAG_NO_UNKNOWN_PRAGMAS  = -Wno-unknown-pragmas  # Suppress warnings about unknown pragmas
C_FLAG_DEPS                = -MMD -MP              # Emit per-file header dependency files for incremental rebuilds

C_FLAGS = \
    $(C_FLAG_STD_C99) \
    $(C_FLAG_DEBUG_INFO) \
    $(C_FLAG_HEADERS) \
    $(C_FLAG_ALL_WARNINGS) \
    $(C_FLAG_PEDANTIC) \
    $(C_FLAG_SHADOW) \
	$(C_FLAG_STRICT_PROTOS) \
    $(C_FLAG_NO_UNKNOWN_PRAGMAS) \
    $(C_FLAG_DEPS)

# BUILD-MODE FLAGS
RELEASE_FLAGS = -O2
DEBUG_FLAGS   = -O0 -DDEBUG -fsanitize=address,undefined -fno-omit-frame-pointer

# INCLUDE FLGAS
INCLUDE_FLAGS = \
	-Iinclude \
	$(EXTERNAL_FLAGS) \
	$(RAYLIB_CFLAGS)

# EXTERNAL FLAGS
EXTERNAL_RAYGUI = -Iexternal/raygui
EXTERNAL_RINI = -Iexternal/rini
EXTERNAL_FLAGS = \
	$(EXTERNAL_RINI) \
	$(EXTERNAL_RAYGUI)

# CROSS PLATTFORM
ifeq ($(OS), Windows_NT)
	SRC = $(wildcard src\*.c)
	BIN_DIR = bin\win
	RAYLIB_CFLAGS = -I%RAYLIB%
	RAYLIB_LIBS = -L%RAYLIB% -lraylib -lopengl32 -lgdi32 -lwinmm
	EXE_EXT = .exe
else
	SRC = $(wildcard src/*.c)
	BIN_DIR = bin/unix
	RAYLIB_CFLAGS = $(shell pkg-config --cflags raylib)
	RAYLIB_LIBS = $(shell pkg-config --libs raylib) -lm
	EXE_EXT =
endif

TARGET_RELEASE = $(BIN_DIR)/game$(EXE_EXT)
TARGET_DEBUG   = $(BIN_DIR)/game-debug$(EXE_EXT)

# PER-FILE OBJECTS (one .o per .c, only stale ones get rebuilt)
OBJ_DIR_RELEASE = build/release
OBJ_DIR_DEBUG   = build/debug

OBJS_RELEASE = $(patsubst src/%.c,$(OBJ_DIR_RELEASE)/%.o,$(SRC))
OBJS_DEBUG   = $(patsubst src/%.c,$(OBJ_DIR_DEBUG)/%.o,$(SRC))

DEPS_RELEASE = $(OBJS_RELEASE:.o=.d)
DEPS_DEBUG   = $(OBJS_DEBUG:.o=.d)

# COMMANDS
build: $(TARGET_RELEASE)

debug: $(TARGET_DEBUG)

$(TARGET_RELEASE): $(OBJS_RELEASE) | $(BIN_DIR)
	$(COMPILER) $(OBJS_RELEASE) -o $(TARGET_RELEASE) $(RAYLIB_LIBS)

$(TARGET_DEBUG): $(OBJS_DEBUG) | $(BIN_DIR)
	$(COMPILER) $(DEBUG_FLAGS) $(OBJS_DEBUG) -o $(TARGET_DEBUG) $(RAYLIB_LIBS)

$(OBJ_DIR_RELEASE)/%.o: src/%.c | $(OBJ_DIR_RELEASE)
	$(COMPILER) $(C_FLAGS) $(RELEASE_FLAGS) $(INCLUDE_FLAGS) -c $< -o $@

$(OBJ_DIR_DEBUG)/%.o: src/%.c | $(OBJ_DIR_DEBUG)
	$(COMPILER) $(C_FLAGS) $(DEBUG_FLAGS) $(INCLUDE_FLAGS) -c $< -o $@

# DIRECTORIES ARE ORDER-ONLY PREREQUISITES SO `clean` CAN REMOVE THEM WITHOUT
# RACING A CHAINED `build`/`debug` IN THE SAME INVOCATION (e.g. `make clean build`)
$(OBJ_DIR_RELEASE) $(OBJ_DIR_DEBUG) $(BIN_DIR):
	mkdir -p $@

-include $(DEPS_RELEASE)
-include $(DEPS_DEBUG)

clean:
	rm -rf bin build

run: build
	./$(TARGET_RELEASE)

run-debug: debug
	./$(TARGET_DEBUG)

.PHONY: build debug clean run run-debug