Simplify makefile

Makefile

@@ -7,36 +7,30 @@ TEST_DIR = test
 CFLAGS = -g -I$(INC_DIR) -Wall
 LDFLAGS = -lm
 TEST_SRC = $(wildcard $(TEST_DIR)/*.c)
-TARGET_SRC = $(wildcard $(TARGET_DIR)/*.c)
 
-# If `test` is passed as a cmd argument, extend flags to handle unit tests 
 ifeq ($(MAKECMDGOALS), test)
-    SRC = $(wildcard $(SRC_DIR)/*.c)
-    TARGETS = $(patsubst $(TEST_DIR)/%.c,%,$(TEST_SRC))
-    TARGET_DIR = test
-	OBJECTS = $(SRC:%.c=%.o) $(TEST_SRC)
+	# If `test` is passed as a cmd argument, extend flags to handle unit tests 
+	TARGET_SRC = $(wildcard $(TEST_DIR)/*.c)
+	TARGETS = $(patsubst $(TEST_DIR)/%.c,%,$(TEST_SRC))
+	TARGET_DIR = test
 else
-    # Strip file path so each demo source gets a target,
-    # e.g. examples/01_demo.c -> 01_demo
-    TARGETS = $(patsubst $(TARGET_DIR)/%.c, %, $(TARGET_SRC))
-    SRC = $(wildcard $(SRC_DIR)/*.c)
-	OBJECTS = $(SRC:%.c=%.o)
+	# Strip file path so each demo source gets a target,
+	# e.g. examples/01_demo.c -> 01_demo
+	TARGET_SRC = $(wildcard $(TARGET_DIR)/*.c)
+	TARGETS = $(patsubst $(TARGET_DIR)/%.c, %, $(TARGET_SRC))
+	TARGET_DIR = examples
 endif
 
-
 # What to do by default (no arguments)
 all: $(TARGETS)
+test: all
 
 $(TARGETS): %: $(TARGET_DIR)/%.c $(wildcard $(SRC_DIR)/*.c)
 	$(CC) $(CFLAGS) $(SRC_DIR)/*.c $< -o $@ $(LDFLAGS)
 
-%.o: %.c
-	$(CC) $(CFLAGS) -c $< -o $@
-
-test: all
 .PHONY: clean
 
 RM = rm -rf
 clean:
-	$(RM) $(TARGETS) $(SRC_DIR)/*.o test/*.o tests
+	$(RM) $(TARGETS) $(SRC_DIR)/*.o $(TARGET_DIR)/*.o tests