$NetBSD: patch-Makefile,v 1.2 2023/06/26 17:13:01 jperkin Exp $

Use SDL2 and GTK+-3.0 Cflags / Libs only when building files that need them.

--- Makefile.orig	2023-05-20 12:24:50.772165900 +0000
+++ Makefile	2023-05-20 12:37:55.337663884 +0000
@@ -21,13 +21,10 @@
 # This should also work with Windows, using MinGW, if you do LIBS="-lws2_32"
 # Build with CFLAGS=-DDEBUG for CPU trace (will be better integrated later)
 
-CFLAGS := $(CFLAGS) `sdl2-config --cflags` `pkg-config gtk+-3.0 --cflags`
-LIBS   := $(LIBS) `sdl2-config --libs` `pkg-config gtk+-3.0 --libs`
-
 all:	marduk
 
 marduk:	dasm80.o disk.o emu2149.o main.o modem.o tms9918.o tms_util.o z80.o
-	$(CC) $(CFLAGS) -o marduk dasm80.o disk.o emu2149.o main.o modem.o tms9918.o tms_util.o z80.o $(LIBS)
+	$(CC) $(CFLAGS) -o marduk dasm80.o disk.o emu2149.o main.o modem.o tms9918.o tms_util.o z80.o $(LDFLAGS) `sdl2-config --libs` `pkg-config gtk+-3.0 --libs`
 
 dasm80.o:	dasm80.c z80.h
 	$(CC) $(CFLAGS) -c -o dasm80.o dasm80.c
@@ -39,7 +36,8 @@ emu2149.o:	emu2149.c emu2149.h
 	$(CC) $(CFLAGS) -c -o emu2149.o emu2149.c
 
 main.o:	main.c emu2149.h disk.h modem.h tms9918.h tms_util.h z80.h
-	$(CC) $(CFLAGS) -c -o main.o main.c
+	$(CC) $(CFLAGS) `sdl2-config --cflags` `pkg-config gtk+-3.0 --cflags` \
+	    -c -o main.o main.c
 
 modem.o:	modem.c modem.h
 	$(CC) $(CFLAGS) -c -o modem.o modem.c