From a030eff963032f3cc31eac472eabaf6d4c3c4a76 Mon Sep 17 00:00:00 2001
From: Werner Almesberger <werner@almesberger.net>
Date: Thu, 23 Aug 2012 09:04:44 -0300
Subject: [PATCH] cameo/: new command "flip" to flip paths on the X or Y axis

---
 cameo/README |  4 ++++
 cameo/lang.l |  3 +++
 cameo/lang.y | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++--
 3 files changed, 71 insertions(+), 2 deletions(-)

diff --git a/cameo/README b/cameo/README
index 4bbe16b..67407ae 100644
--- a/cameo/README
+++ b/cameo/README
@@ -99,6 +99,7 @@ Horizontal adjustments:
   array <x-step> <y-step> <x-index> <y-index>
   translate <x> <y>
   rotate <angle>
+  flip <axis> [<center>]
   reset
 
 "translate" shifts the currently loaded paths by the specified distance.
@@ -139,6 +140,9 @@ Note that rotation is applied before translation. Therefore, using
 "rotate" after "translate", "array", or "align" may yield unexpected
 results.
 
+"flip" flips X/Y coordinates on the respective axis ("x" or "y"). If
+the center is omitted, the piece is flipped on (xymin+xymax)/2.
+
 "reset" sets translation and rotation to zero. The way "reset" is currently
 implemented, it does not affect the currently loaded toolpath. (But it's
 better to use it only with "clean".)
diff --git a/cameo/lang.l b/cameo/lang.l
index a6048b9..70bdd5a 100644
--- a/cameo/lang.l
+++ b/cameo/lang.l
@@ -45,6 +45,7 @@ NUM	-?[0-9]+\.?[0-9]*
 <INITIAL>clear			return TOK_CLEAR;
 <INITIAL>drill			return TOK_DRILL;
 <INITIAL>empty			return TOK_EMPTY;
+<INITIAL>flip			return TOK_FLIP;
 <INITIAL>keep			return TOK_KEEP;
 <INITIAL>mill			return TOK_MILL;
 <INITIAL>offset			return TOK_OFFSET;
@@ -57,6 +58,8 @@ NUM	-?[0-9]+\.?[0-9]*
 <INITIAL>rotate			return TOK_ROTATE;
 <INITIAL>stats			return TOK_STATS;
 <INITIAL>translate		return TOK_TRANSLATE;
+<INITIAL>x			return TOK_X;
+<INITIAL>y			return TOK_Y;
 <INITIAL>z			return TOK_Z;
 
 <INITIAL>append			{ BEGIN(FILENAME);
diff --git a/cameo/lang.y b/cameo/lang.y
index 1c12aae..b572271 100644
--- a/cameo/lang.y
+++ b/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:
 	| ','
 	;