Makefile

ifneq (,$(findstring clean, $(MAKECMDGOALS))) # Prevent searching for compilers if the make target clean
else
CHECK := $(shell g++ --version >/dev/null 2>&1 || (echo "Failed to search for g++ with error: $$"))
ifeq (,${CHECK})
    COMPILER := g++
$(info C++ compiler found: g++)
$(info )

else # Check for clang if g++ is unavailable
    CHECK2 := $(shell clang --version >/dev/null 2>&1 || (echo "Failed to search for clang with error: $$?"))
	ifeq (,${CHECK2})
$(info C++ compiler found: clang)
$(info )
		COMPILER := clang
		LIBS := -lstdc++
	else
$(error No C++ compilers found.)
	endif
endif

ifneq (,$(findstring xterm,${TERM}))
	FLAGS = -D COLOR
endif

endif

FLAGS += -O3 -DNDEBUG -D CHECKVALIDITY -fopenmp -MMD
LIBS  := -lm -lpopt -lglut -lGLU -lGL -lpthread ${LIBS}
BUILD := build
SRC := src
OBJ := ${BUILD}/obj
SHARED_OBJ := ${BUILD}/shared
BIN := ${BUILD}/bin

EXECUTABLE := ${BIN}/polygonGenerator
SHARED_LIBRARY := ${BIN}/polygonGenerator.so

SRCS := $(wildcard $(SRC)/*.cpp) $(wildcard $(SRC)/*/*.cpp)
OBJS := $(patsubst $(SRC)/%.cpp, $(OBJ)/%.o, $(SRCS))
SHARED_OBJS := $(patsubst $(SRC)/%.cpp, $(SHARED_OBJ)/%.o, $(SRCS))
SUBDIRECTORIES := $(sort $(dir $(wildcard $(SRC)/*/)))
DIRECTORIES := $(patsubst $(SRC)/%, $(SHARED_OBJ)/%, $(SUBDIRECTORIES)) $(patsubst $(SRC)/%, $(OBJ)/%, $(SUBDIRECTORIES)) ${BIN}

DEPS := $(OBJS:.o=.d)
-include $(DEPS)

$(shell mkdir -p ${DIRECTORIES})

# .PHONY means these rules get executed even if files of those names exist.
.PHONY: clean

polygonGenerator: ${OBJS}
	${COMPILER} ${FLAGS} -o ${EXECUTABLE} $^ ${LIBS}
	@echo
	@echo "Compiled Successfully!! Run the program using ./${EXECUTABLE}"

debug: FLAGS := -g -Wall -D DEBUG -D CHECKVALIDITY
debug: ${OBJS}
	${COMPILER} ${FLAGS} -o ${EXECUTABLE} $^ ${LIBS}
	@echo
	@echo "Compiled Successfully!! Run the program using ./${EXECUTABLE}"

polygonGenerator_SharedLibrary: FLAGS := ${FLAGS} -shared -fPIC -pie
polygonGenerator_SharedLibrary: ${SHARED_OBJS}
	${COMPILER} ${FLAGS} -o ${SHARED_LIBRARY} $^ ${LIBS}
	@echo
	@echo "Compiled Successfully!! The Shared Library is available as" ${SHARED_LIBRARY}

${OBJ}/%.o: ${SRC}/%.cpp
	${COMPILER} ${FLAGS} -c $< -o $@

${SHARED_OBJ}/%.o: ${SRC}/%.cpp
	${COMPILER} ${FLAGS} -c $< -o $@

clean:
	rm -rf ${BUILD}