cameo/: new command "flip" to flip paths on the X or Y axis

cameo/lang.y

@@ -80,6 +80,43 @@ static void rotate(struct path *list, double angle)
 }
 
 
+static void flip(struct path *list, enum axis axis, double center)
+{
+	const struct path *path;
+	struct point *p;
+
+	for (path = list; path; path = path->next)
+		for (p = path->first; p; p = p->next) {
+			if (axis == axis_x)
+				p->x = 2*center-p->x;
+			else
+				p->y = 2*center-p->y;
+		}
+}
+
+
+
+static void flip_center(struct path *list, enum axis axis)
+{
+	double min = 0, max = 0;
+	double coord;
+	const struct path *path;
+	const struct point *p;
+	int first = 1;
+
+	for (path = list; path; path = path->next)
+		for (p = path->first; p; p = p->next) {
+			coord = axis == axis_x ? p->x : p->y;
+			if (first || coord < min)
+				min = coord;
+			if (first || coord > max)
+				max = coord;
+			first = 0;
+		}
+	flip(list, axis, (min+max)/2);
+}	
+
+
 static double ref_pick_1(int ref, double a, double b)
 {
 	switch (ref) {
@@ -184,14 +221,19 @@ static struct path **classify(struct path **anchor, struct path *path)
 		OO_DOG		= 1 << 0,
 		OO_INSIDE	= 1 << 1,
 	} oopt;
+	enum axis {
+		axis_x,
+		axis_y
+	} axis;
 };
 
 
 %token		TOK_ALIGN TOK_AREA TOK_ARRAY TOK_CLEAR TOK_DRILL TOK_EMPTY
-%token		TOK_KEEP TOK_MILL TOK_OFFSET TOK_OPTIMIZE
+%token		TOK_FLIP TOK_KEEP TOK_MILL TOK_OFFSET TOK_OPTIMIZE
 %token		TOK_OUTSIDE TOK_REMAINDER
 %token		TOK_REMOVE TOK_RESET
-%token		TOK_REVERSE TOK_ROTATE TOK_STATS TOK_TRANSLATE TOK_Z
+%token		TOK_REVERSE TOK_ROTATE TOK_STATS TOK_TRANSLATE
+%token		TOK_X TOK_Y TOK_Z
 %token		TOK_APPEND TOK_GERBER TOK_GNUPLOT TOK_EXCELLON TOK_WRITE
 %token		TOK_DOG TOK_INSIDE TOK_ANY
 
@@ -202,6 +244,7 @@ static struct path **classify(struct path **anchor, struct path *path)
 %type	<num>	dimen number x_size y_size
 %type	<flag>	opt_any
 %type	<oopt>	offset_options offset_option
+%type	<axis>	axis
 
 %%
 
@@ -283,6 +326,14 @@ command:
 			rotate(paths, $2);
 			rot += $2;
 		}
+	| TOK_FLIP axis
+		{
+			flip_center(paths, $2);
+		}
+	| TOK_FLIP axis dimen
+		{
+			flip(paths, $2, $3);
+		}
 	| TOK_STATS
 		{
 			path_stats(paths);
@@ -489,6 +540,17 @@ offset_option:
 		}
 	;
 
+axis:
+	TOK_X
+		{
+			$$ = axis_x;
+		}
+	| TOK_Y
+		{
+			$$ = axis_y;
+		}
+	;
+
 opt_comma:
 	| ','
 	;