+ifeq ($(TARGET),sdl) # compiling for SDL target
+SYS_CFLAGS = -DTARGET_SDL $(shell sdl-config --cflags)
+SDL_LIBS = -lSDL_image -lSDL_mixer -lSDL_net -lsmpeg
+SYS_LDFLAGS = $(SDL_LIBS) $(shell sdl-config --libs)
+endif
+
+ifeq ($(TARGET),sdl2) # compiling for SDL2 target
+SYS_CFLAGS = -DTARGET_SDL2 $(shell sdl2-config --cflags)
+SDL_LIBS = -lSDL2_image -lSDL2_mixer -lSDL2_net -lsmpeg2
+SYS_LDFLAGS = $(SDL_LIBS) $(shell sdl2-config --libs)
+endif
+
+ifeq ($(TARGET),sdl-static) # compiling for SDL target (static)
+SYS_CFLAGS = -DTARGET_SDL $(shell sdl-config --cflags)
+SDL_LIBS = -lSDL_image -lSDL_mixer -lSDL_net -lsmpeg -lmikmod
+SYS_LDFLAGS = $(SDL_LIBS) $(shell sdl-config --static-libs)
+endif
+
+ifeq ($(TARGET),allegro) # compiling for Allegro target
+SYS_CFLAGS = -DTARGET_ALLEGRO -I$(CROSS_PATH_MSDOS)/include
+SYS_LDFLAGS = -lalleg
+endif
+
+
+# -----------------------------------------------------------------------------
+# configuring compile-time definitions
+# -----------------------------------------------------------------------------
+
+ifdef RO_GAME_DIR # path to read-only game data specified
+CONFIG_RO_GAME_DIR = -DRO_GAME_DIR="\"$(RO_GAME_DIR)\""
+endif
+
+ifdef RW_GAME_DIR # path to writable game data specified
+CONFIG_RW_GAME_DIR = -DRW_GAME_DIR="\"$(RW_GAME_DIR)\""
+endif
+
+ifdef SCORE_ENTRIES # number of score entries per player
+CONFIG_SCORE_ENTRIES = -D$(SCORE_ENTRIES)
+endif
+
+ifdef SPECIAL_EDITION
+ifeq ($(SPECIAL_EDITION),rnd_jue) # create special edition
+CONFIG_SPECIAL = -DCREATE_SPECIAL_EDITION -DCREATE_SPECIAL_EDITION_RND_JUE
+endif
+endif
+
+CONFIG_GAME_DIR = $(CONFIG_RO_GAME_DIR) $(CONFIG_RW_GAME_DIR)
+CONFIG_GAME = $(CONFIG_GAME_DIR) $(CONFIG_SCORE_ENTRIES) $(CONFIG_SPECIAL)
+
+CONFIG = $(CONFIG_GAME) $(JOYSTICK)
+DEBUG = -DDEBUG -g
+# PROFILING = $(PROFILING_FLAGS)
+
+# OPTIONS = $(DEBUG) -Wall # only for debugging purposes
+# OPTIONS = $(DEBUG) -O3 -Wall # only for debugging purposes
+OPTIONS = $(DEBUG) -Wall # only for debugging purposes
+# OPTIONS = $(DEBUG) -Wall -ansi -pedantic # only for debugging purposes
+# OPTIONS = -O3 -Wall -ansi -pedantic
+# OPTIONS = -O3 -Wall
+# OPTIONS = -O3
+# OPTIONS = -DSYSV -Ae # may be needed for HP-UX
+
+ifdef BUILD_DIST # distribution build
+OPTIONS = -O3 -Wall
+endif
+
+CFLAGS = $(OPTIONS) $(SYS_CFLAGS) $(EXTRA_CFLAGS) $(CONFIG)
+LDFLAGS = $(SYS_LDFLAGS) $(EXTRA_LDFLAGS) -lm