Reorganize code and remove hack for empty block outputs

Makefile

@@ -1,21 +1,36 @@
 .POSIX:
 
-PREFIX = /usr/local
-CFLAGS = -Ofast
-LDLIBS = -lX11
+BUILD_DIR := build
+SRC_DIR := src
+INC_DIR := inc
 
-BIN = dwmblocks
+PREFIX := /usr/local
+CFLAGS := -Wall -Ofast -I. -I$(INC_DIR)
+LDLIBS := -lX11
 
-$(BIN): main.o
-	$(CC) $^ -o $@ $(LDLIBS)
+BIN := dwmblocks
+VPATH := $(SRC_DIR)
+OBJS := $(subst $(SRC_DIR)/,$(BUILD_DIR)/,$(subst .c,.o,$(wildcard $(SRC_DIR)/*.c)))
+OBJS += $(addprefix $(BUILD_DIR)/,$(subst .c,.o,$(wildcard *.c)))
+
+all: $(BUILD_DIR)/$(BIN)
+
+$(BUILD_DIR)/$(BIN): $(OBJS)
+	$(LINK.o) $^ $(LDLIBS) -o $@
+
+$(BUILD_DIR)/%.o: %.c config.h | $(BUILD_DIR)
+	$(COMPILE.c) -o $@ $<
+
+$(BUILD_DIR):
+	mkdir -p $(BUILD_DIR)
 
 clean:
-	$(RM) *.o $(BIN)
+	$(RM) -r $(BUILD_DIR)
 
-install: $(BIN)
-	install -D -m 755 $(BIN) $(DESTDIR)$(PREFIX)/bin/$(BIN)
+install: $(BUILD_DIR)/$(BIN)
+	install -D -m 755 $< $(DESTDIR)/$(PREFIX)/bin/$(BIN)
 
 uninstall:
-	$(RM) $(DESTDIR)$(PREFIX)/bin/$(BIN)
+	$(RM) $(DESTDIR)/$(PREFIX)/bin/$(BIN)
 
-.PHONY: clean install uninstall
+.PHONY: all clean install uninstall