cameo: added "rotate" command

- lang.l, lang.y (rotate): added command "rotate", with cumulative
  rotation
- README: documented "rotate"
- README: corrected typo in description of the translation commands

cameo/README

@@ -88,6 +88,7 @@ Horizontal adjustments:
   align <ref> <x0> <y0> <x1> <y1>
   array <x-step> <y-step> <x-index> <y-index>
   translate <x> <y>
+  rotate <angle>
   reset
 
 "translate" shifts the currently loaded paths by the specified distance.
@@ -110,12 +111,19 @@ The reference point is specified with a number as follows:
 two arguments define the step between pieces while the second two
 arguments define how many steps in each direction are taken.
 
-"align" sets moves the toolpath to an absolute position while "array" and
+"align" moves the toolpath to an absolute position while "array" and
 "translate" move relative to the current position. The total translation
 is remembered also across "clean", so that an alignment can be applied to
 multiple toolpaths.
 
-"reset" sets the translation to zero. The way "reset" is currently
+"rotate" rotates the currenly loaded paths by the specified number of
+degrees in a counter-clockwise direction. Like translations, rotations
+are accumulated and are automatically applied to files loaded later.
+Note that rotation is applied before translation. Therefore, using
+"rotate" after "translate", "array", or "align" may yield unexpected
+results.
+
+"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".)
 

cameo/lang.l

@@ -49,6 +49,7 @@ NUM	-?[0-9]+\.?[0-9]*
 <INITIAL>optimize		return TOK_OPTIMIZE;
 <INITIAL>remainder		return TOK_REMAINDER;
 <INITIAL>reset			return TOK_RESET;
+<INITIAL>rotate			return TOK_ROTATE;
 <INITIAL>translate		return TOK_TRANSLATE;
 <INITIAL>z			return TOK_Z;
 

cameo/lang.y

@@ -13,6 +13,8 @@
 
 
 #include <stdlib.h>
+#include <stdio.h>
+#include <math.h>
 
 #include "path.h"
 #include "ops.h"
@@ -23,7 +25,8 @@
 #include "y.tab.h"
 
 
-static double xo = 0, yo = 0, zo = 0;
+static double xo = 0, yo = 0, zo = 0;	/* origin */
+static double rot = 0;
 static struct path *paths = NULL;
 static struct path *remain = NULL;
 
@@ -55,6 +58,27 @@ static void translate(struct path *list, double x, double y, double z)
 }
 
 
+static void rotate(struct path *list, double angle)
+{
+	double m[2][2], tmp;
+	struct point *p;
+
+	angle = angle/180.0*M_PI;
+	m[0][0] = cos(angle);
+	m[0][1] = -sin(angle);
+	m[1][0] = -m[0][1];
+	m[1][1] = m[0][0];
+	while (list) {
+		for (p = list->first; p; p = p->next) {
+			tmp = p->x*m[0][0]+p->y*m[0][1];
+			p->y = p->x*m[1][0]+p->y*m[1][1];
+			p->x = tmp;
+		}
+		list = list->next;
+	}
+}
+
+
 static double ref_pick_1(int ref, double a, double b)
 {
 	switch (ref) {
@@ -151,7 +175,7 @@ static struct path **classify(struct path **anchor, struct path *path)
 
 %token		TOK_ALIGN TOK_ARRAY TOK_CLEAR TOK_DRILL TOK_EMPTY
 %token		TOK_MILL TOK_OFFSET TOK_OPTIMIZE TOK_REMAINDER TOK_RESET
-%token		TOK_TRANSLATE TOK_Z
+%token		TOK_ROTATE TOK_TRANSLATE TOK_Z
 %token		TOK_APPEND TOK_GERBER TOK_GNUPLOT TOK_EXCELLON TOK_WRITE
 %token		TOK_DOG TOK_INSIDE
 
@@ -201,7 +225,7 @@ command:
 		}
 	| TOK_RESET
 		{
-			xo = yo = 0;
+			xo = yo = rot = 0;
 		}
 	| TOK_OFFSET offset_options
 		{
@@ -212,6 +236,11 @@ command:
 		{
 			paths = optimize_paths(paths);
 		}
+	| TOK_ROTATE number
+		{
+			rotate(paths, $2);
+			rot += $2;
+		}
 	| TOK_TRANSLATE dimen dimen
 		{
 			translate(paths, $2, $3, 0);
@@ -231,6 +260,7 @@ command:
 			struct path *new;
 
 			new = gerber_read($3, $2/2);
+			rotate(new, rot);
 			translate(new, xo, yo, 0);
 			add_paths(new);
 		}
@@ -239,6 +269,7 @@ command:
 			struct path *new;
 
 			new = gnuplot_read($3, $2/2);
+			rotate(new, rot);
 			translate(new, xo, yo, 0);
 			add_paths(new);
 		}
@@ -247,6 +278,7 @@ command:
 			struct path *new;
 
 			new = excellon_read($2);
+			rotate(new, rot);
 			translate(new, xo, yo, 0);
 			add_paths(new);
 		}