update libpng

update libpng, the repo now requires a vcpkg setup for integrating but skipping the install step should allow it to work for windows an linux, mac might need more

Engine/lib/lpng/scripts/makefile.atari

@@ -1,4 +1,5 @@
 # makefile for libpng
+# Copyright (C) 2022-2025 Cosmin Truta
 # Copyright (C) 2002, 2014 Glenn Randers-Pehrson
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
 #
@@ -9,40 +10,25 @@
 # Modified for LC56/ATARI assumes libz.lib is in same dir and uses default
 # rules for library management
 #
-CPPFLAGS = -I..\zlib
+CPPFLAGS = -I../zlib
 CFLAGS = -O
 LBR = png.lib
-LDFLAGS = -L. -L..\zlib -lpng -lz -lm
-
-# where make install puts libpng.a and png.h
-prefix=/usr/local
-INCPATH=$(prefix)/include
-LIBPATH=$(prefix)/lib
-
-# override DESTDIR= on the make install command line to easily support
-# installing into a temporary location.  Example:
-#
-#    make install DESTDIR=/tmp/build/libpng
-#
-# If you're going to install into a temporary location
-# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
-# you execute make install.
-DESTDIR=
+LDFLAGS = -L. -L../zlib -lpng -lz -lm
 
 # Pre-built configuration
 # See scripts/pnglibconf.mak for more options
 PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
 
-OBJS = $(LBR)(png.o) $(LBR)(pngset.o) $(LBR)(pngget.o) $(LBR)(pngrutil.o)\
-	$(LBR)(pngtrans.o) $(LBR)(pngwutil.o)\
-	$(LBR)(pngread.o) $(LBR)(pngerror.o) $(LBR)(pngwrite.o)\
-	$(LBR)(pngrtran.o) $(LBR)(pngwtran.o)\
-	$(LBR)(pngmem.o) $(LBR)(pngrio.o) $(LBR)(pngwio.o) $(LBR)(pngpread.o)
+OBJS = $(LBR)(png.o) $(LBR)(pngerror.o) $(LBR)(pngget.o) $(LBR)(pngmem.o) \
+       $(LBR)(pngpread.o) $(LBR)(pngread.o) $(LBR)(pngrio.o) \
+       $(LBR)(pngrtran.o) $(LBR)(pngrutil.o) $(LBR)(pngset.o) \
+       $(LBR)(pngtrans.o) $(LBR)(pngwio.o) $(LBR)(pngwrite.o) \
+       $(LBR)(pngwtran.o) $(LBR)(pngwutil.o)
 
 all: $(LBR) pngtest.ttp
 
 .c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) $<
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) $*.c
 
 $(LBR): $(OBJS)
 
@@ -54,18 +40,6 @@ pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
 pngtest.ttp: pngtest.o $(LBR)
 	$(CC) $(CFLAGS) $(LDFLAGS) -o$@ pngtest.o
 
-install: libpng.a
-	-@mkdir $(DESTDIR)$(INCPATH)
-	-@mkdir $(DESTDIR)$(INCPATH)/libpng
-	-@mkdir $(DESTDIR)$(LIBPATH)
-	-@rm -f $(DESTDIR)$(INCPATH)/png.h
-	-@rm -f $(DESTDIR)$(INCPATH)/pngconf.h
-	-@rm -f $(DESTDIR)$(INCPATH)/pnglibconf.h
-	cp png.h $(DESTDIR)$(INCPATH)/libpng
-	cp pngconf.h $(DESTDIR)$(INCPATH)/libpng
-	cp pnglibconf.h $(DESTDIR)$(INCPATH)/libpng
-	chmod 644 $(DESTDIR)$(INCPATH)/libpng/png.h
-	chmod 644 $(DESTDIR)$(INCPATH)/libpng/pngconf.h
-	chmod 644 $(DESTDIR)$(INCPATH)/libpng/pnglibconf.h
-	(cd $(DESTDIR)$(INCPATH); ln -f -s $(LIBNAME) libpng; \
-	ln -f -s $(LIBNAME)/* .)
+install:
+	@echo "The $@ target is no longer supported by this makefile."
+	@false