Fixed issue with flip filters

src/nasu.tal

@@ -544,7 +544,8 @@ JMP2r
 	( ) ADD2 LTH2 ?{ POP2 POP2 JMP2r }
 	( write )
 	STH2 DUP2 ,&x1 STR2
-	[ LIT2 00 -selection/x2 ] LDZ INC #30 SFT2 #0001 SUB2 SWP2 SUB2 ,&x2 STR2
+	[ LIT2 00 -selection/x2 ] LDZ INC #30 SFT2 #0001 SUB2 SWP2 SUB2
+	[ LIT2 00 -selection/x1 ] LDZ #30 SFT2 ADD2 ,&x2 STR2
 	[ LIT2 &x1 $2 ] STH2kr get-pixel ,&c1 STR
 	[ LIT2 &x2 $2 ] STH2kr get-pixel ,&c2 STR
 	,&x2 LDR2 STH2kr [ LIT &c1 $1 ] put-pixel
@@ -558,11 +559,12 @@ JMP2r
 	( ) ADD2 LTH2 ?{ POP2 POP2 JMP2r }
 	( write )
 	DUP2 ,&y1 STR2
-	[ LIT2 00 -selection/y2 ] LDZ INC #30 SFT2 #0001 SUB2 SWP2 SUB2 ,&y2 STR2
-	DUP2 [ LIT2 &y1 $2 ]  get-pixel ,&c1 STR
-	DUP2 [ LIT2 &y2 $2 ]  get-pixel ,&c2 STR
-	DUP2 ,&y2 LDR2  [ LIT &c1 $1 ] put-pixel
-	 ,&y1 LDR2  [ LIT &c2 $1 ] !put-pixel
+	[ LIT2 00 -selection/y2 ] LDZ INC #30 SFT2 #0001 SUB2 SWP2 SUB2 
+	[ LIT2 00 -selection/y1 ] LDZ #30 SFT2 ADD2 ,&y2 STR2
+	DUP2 [ LIT2 &y1 $2 ] get-pixel ,&c1 STR
+	DUP2 [ LIT2 &y2 $2 ] get-pixel ,&c2 STR
+	DUP2 ,&y2 LDR2 [ LIT &c1 $1 ] put-pixel
+	,&y1 LDR2 [ LIT &c2 $1 ] !put-pixel
 
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 @|map )