When dragging an endpoint of an inverted measurement, we didn't consider that

inst->base and inst->u.meas.end are swapped, causing fped to crash in vec_at.
Also introduced a universal swap() function.

- util.h (swap): new swap function for arguments of any type
- gui_meas.c (begin_drag_move_meas, draw_move_meas): swap the endpoints if
  moving an inverted measurement
- coord.c (sort_coord): use swap() instead of swap_coord
- coord.h, coord.c (swap_coord): removed
- gui_util.c (save_pix_buf): use swap() instead of open-coding the swap 
- kicad.c (kicad_centric): use sort_coord instead of "manually" sorting the
  coordinates



git-svn-id: http://svn.openmoko.org/trunk/eda/fped@5968 99fdad57-331a-0410-800a-d7fa5415bdb3

coord.c

@@ -1,8 +1,8 @@
 /*
  * coord.c - Coordinate representation and basic operations
  *
- * Written 2009 by Werner Almesberger
- * Copyright 2009 by Werner Almesberger
+ * Written 2009, 2010 by Werner Almesberger
+ * Copyright 2009, 2010 by Werner Almesberger
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -13,6 +13,7 @@
 
 #include <math.h>
 
+#include "util.h"
 #include "coord.h"
 
 
@@ -153,22 +154,12 @@ double theta(struct coord c, struct coord p)
 /* ----- sorting coordinates ----------------------------------------------- */
 
 
-void swap_coord(unit_type *a, unit_type *b)
-{
-	unit_type tmp;
-
-	tmp = *a;
-	*a = *b;
-	*b = tmp;
-}
-
-
 void sort_coord(struct coord *min, struct coord *max)
 {
 	if (min->x > max->x)
-		swap_coord(&min->x, &max->x);
+		swap(min->x, max->x);
 	if (min->y > max->y)
-		swap_coord(&min->y, &max->y);
+		swap(min->y, max->y);
 
 }
 

coord.h

@@ -1,8 +1,8 @@
 /*
  * coord.h - Coordinate representation and basic operations
  *
- * Written 2009 by Werner Almesberger
- * Copyright 2009 by Werner Almesberger
+ * Written 2009, 2010 by Werner Almesberger
+ * Copyright 2009, 2010 by Werner Almesberger
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -87,7 +87,6 @@ struct coord rotate_r(struct coord c, unit_type r, double angle);
 double theta_vec(struct coord v);
 double theta(struct coord c, struct coord p);
 
-void swap_coord(unit_type *a, unit_type *b);
 void sort_coord(struct coord *min, struct coord *max);
 
 unit_type dist_point(struct coord a, struct coord b);

gui_meas.c

@@ -189,7 +189,8 @@ static void meas_highlight_b(void)
 
 struct pix_buf *draw_move_meas(struct inst *inst, struct coord pos, int i)
 {
-	return draw_move_line_common(inst, inst->u.meas.end, pos, i);
+	return draw_move_line_common(inst, inst->u.meas.end, pos,
+	    inst->obj->u.meas.inverted ? 1-i : i);
 }
 
 
@@ -349,6 +350,7 @@ static struct inst *vec_at(const struct vec *vec, struct coord pos)
 void begin_drag_move_meas(struct inst *inst, int i)
 {
 	const struct meas *meas = &inst->obj->u.meas;
+	struct coord a, b;
 
 	switch (meas->type) {
 	case mt_xy_next:
@@ -367,14 +369,24 @@ void begin_drag_move_meas(struct inst *inst, int i)
 		abort();
 	}
 	highlight = meas_highlight_b;
+
+	/*
+	 * We're setting up the same conditions as after picking the first
+	 * point when making a new measurement. Thus, we set meas_inst to the
+	 * vector to the endpoint we're not moving.
+	 */
+	a = inst->base;
+	b = inst->u.meas.end;
+	if (inst->obj->u.meas.inverted)
+		swap(a, b);
 	switch (i) {
 	case 0:
 		mode = meas->type < 3 ? next_to_min : max_to_min;
-		meas_inst = vec_at(inst->obj->u.meas.high, inst->u.meas.end);
+		meas_inst = vec_at(inst->obj->u.meas.high, b);
 		break;
 	case 1:
 		mode = min_to_next_or_max;
-		meas_inst = vec_at(inst->obj->base, inst->base);
+		meas_inst = vec_at(inst->obj->base, a);
 		break;
 	default:
 		abort();

gui_util.c

@@ -65,19 +65,12 @@ struct pix_buf *save_pix_buf(GdkDrawable *da, int xa, int ya, int xb, int yb,
     int border)
 {
 	struct pix_buf *buf;
-	int tmp;
 	int w, h;
 
-	if (xa > xb) {
-		tmp = xa;
-		xa = xb;
-		xb = tmp;
-	}
-	if (ya > yb) {
-		tmp = ya;
-		ya = yb;
-		yb = tmp;
-	}
+	if (xa > xb)
+		swap(xa, xb);
+	if (ya > yb)
+		swap(ya, yb);
 	buf = alloc_type(struct pix_buf);
 	buf->da = da;
 	buf->x = xa-border;

kicad.c

@@ -30,23 +30,13 @@ static void kicad_centric(struct coord a, struct coord b,
     struct coord *center, struct coord *size)
 {
 	struct coord min, max;
-	unit_type tmp;
 
 	min.x = units_to_kicad(a.x);
 	min.y = units_to_kicad(a.y);
 	max.x = units_to_kicad(b.x);
 	max.y = units_to_kicad(b.y);
 
-	if (min.x > max.x) {
-		tmp = min.x;
-		min.x = max.x;
-		max.x = tmp;
-	}
-	if (min.y > max.y) {
-		tmp = min.y;
-		min.y = max.y;
-		max.y = tmp;
-	}
+	sort_coord(&min, &max);
 
 	size->x = max.x-min.x;
 	size->y = max.y-min.y;

util.h

@@ -1,8 +1,8 @@
 /*
  * util.h - Common utility functions
  *
- * Written 2006, 2009 by Werner Almesberger
- * Copyright 2006, 2009 Werner Almesberger
+ * Written 2006, 2009, 2010 by Werner Almesberger
+ * Copyright 2006, 2009, 2010 Werner Almesberger
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -51,6 +51,11 @@
 	strnalloc_tmp[n] = 0;				\
 	strnalloc_tmp; })
 
+#define swap(a, b) \
+    ({	typeof(a) swap_tmp = (a);			\
+	(a) = (b);					\
+	(b) = swap_tmp; })
+
 
 char *stralloc_vprintf(const char *fmt, va_list ap);
 char *stralloc_printf(const char *fmt, ...)