clean up a lot

Makefile

@@ -4,15 +4,18 @@ CC=gcc
 CFLAGS=-O3 -Iinclude -g
 LDFLAGS=-lglfw -lm
 
-CFILES=$(shell find -L src -type f -name '*.c')
-OBJ=$(CFILES:.c=.o)
+CFILES=$(shell cd src && find -L * -type f -name '*.c')
+OBJ=$(addprefix obj/, $(CFILES:.c=.o))
 
-$(BINARY): $(OBJ) Makefile
+$(BINARY): objdir $(OBJ) Makefile
 	$(CC) $(OBJ) $(LDFLAGS) -o $@
 
-%.o: %.c
+obj/%.o: src/%.c
 	$(CC) $(CFLAGS) -c $< -o $@
 
+objdir:
+	mkdir -p obj
+
 run: $(BINARY)
 	./$(BINARY)