Added flipy

src/nasu.tal

@@ -551,8 +551,18 @@ JMP2r
 	,&x1 LDR2 STH2r [ LIT &c2 $1 ] !put-pixel
 
 @filter-flipy ( x* y* -- )
-	POP2 POP2
+	( ignore second half )
-	JMP2r
+	DUP2
+	( ) [ LIT2 00 -selection/y1 ] LDZ #30 SFT2
+	( ) [ LIT2 00 -selection/y2 ] LDZ INC #30 SFT2 OVR2 SUB2 #01 SFT2
+	( ) 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
 
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 @|map )