+ifdef BUILD_DIST # distribution build
+ifeq ($(shell uname -s),Darwin) # compiling on Mac OS X
+MAC_TARGET_VERSION_MIN = 10.7
+EXTRA_FLAGS_MAC = -mmacosx-version-min=$(MAC_TARGET_VERSION_MIN)
+EXTRA_CFLAGS = $(EXTRA_FLAGS_MAC)
+EXTRA_LDFLAGS = $(EXTRA_FLAGS_MAC)
+MACOSX_DEPLOYMENT_TARGET = $MAC_TARGET_VERSION_MIN
+endif
+endif
+
+
+# -----------------------------------------------------------------------------
+# configuring target
+# -----------------------------------------------------------------------------
+
+ifndef TARGET # auto-detect compiling for SDL2
+ SDL_VERSION := $(shell sdl2-config --version 2> /dev/null)
+ ifdef SDL_VERSION
+ TARGET = sdl2
+ else
+ $(error SDL2 library not found)
+ endif
+endif
+
+# $(info Using SDL version $(SDL_VERSION) [TARGET == $(TARGET)])
+
+ifeq ($(TARGET),sdl2) # compiling for SDL2 target
+SYS_CFLAGS = -DTARGET_SDL2 $(shell sdl2-config --cflags)
+SDL_LIBS = -lSDL2_image -lSDL2_mixer -lSDL2_net
+SYS_LDFLAGS = $(SDL_LIBS) $(shell sdl2-config --libs)
+endif
+
+
+# -----------------------------------------------------------------------------
+# configuring compile-time definitions
+# -----------------------------------------------------------------------------
+
+ifdef RO_GAME_DIR # path to read-only game data specified
+CONFIG_RO_GAME_DIR = -DRO_GAME_DIR="\"$(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
+
+CONFIG = $(CONFIG_RO_GAME_DIR) $(CONFIG_RW_GAME_DIR) $(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 -Wstrict-prototypes -Wmissing-prototypes
+# OPTIONS = $(DEBUG) -Wall -ansi -pedantic # only for debugging purposes
+# OPTIONS = -O3 -Wall -ansi -pedantic
+# OPTIONS = -O3 -Wall
+# OPTIONS = -O3
+
+ifdef BUILD_DIST # distribution build
+SYS_LDFLAGS := $(shell echo $(SYS_LDFLAGS) | \
+ sed -e "s%-rpath,[^ ]*%-rpath,'\$$ORIGIN/lib'%")
+OPTIONS = -O3 -Wall
+endif
+
+CFLAGS = $(OPTIONS) $(SYS_CFLAGS) $(EXTRA_CFLAGS) $(CONFIG)
+LDFLAGS = $(SYS_LDFLAGS) $(EXTRA_LDFLAGS) -lm -lz