Index: trunk/src/draw.c
===================================================================
--- trunk/src/draw.c	(revision 804)
+++ trunk/src/draw.c	(revision 805)
@@ -26,23 +26,10 @@
 
 #include <librnd/hid/hid.h>
 #include <librnd/hid/hid_inlines.h>
+#include <librnd/core/xform_mx.h>
 #include "obj_any.h"
 #include "conf_core.h"
 
-/* based on https://math.stackexchange.com/questions/13150/extracting-rotation-scale-values-from-2d-transformation-matrix/13165#13165 */
-static double mx_extract_rot(rnd_xform_mx_t mx)
-{
-	return atan2(mx[3], mx[4]) * RND_RAD_TO_DEG;
-}
-static void mx_extract_scale(rnd_xform_mx_t mx, double *sx, double *sy)
-{
-	*sx = sqrt(mx[0] * mx[0] + mx[1] * mx[1]);
-	*sy = sqrt(mx[3] * mx[3] + mx[4] * mx[4]);
-/* This would be needed for mirroring
-	if (mx[0] < 0) *sx = -(*sx);
-	if (mx[4] < 0) *sy = -(*sy);*/
-}
-
 static rnd_coord_t MIN4(rnd_coord_t a, rnd_coord_t b, rnd_coord_t c, rnd_coord_t d)
 {
 	rnd_coord_t min = a;
@@ -71,8 +58,8 @@
 	if (ly->enable_mx) {
 		rnd_coord_t x1, y1, x2, y2, x3, y3, x4, y4, sx, sy;
 		mx = &ly->mx;
-		ly->mx_rotdeg = mx_extract_rot(*mx);
-		mx_extract_scale(*mx, &ly->mx_sx, &ly->mx_sy);
+		ly->mx_rotdeg = rnd_xform_mx_extract_rot(*mx);
+		rnd_xform_mx_extract_scale(*mx, &ly->mx_sx, &ly->mx_sy);
 		x1 = rnd_xform_x((*mx), view->x1, view->y1);
 		y1 = rnd_xform_y((*mx), view->x1, view->y1);
 		x2 = rnd_xform_x((*mx), view->x2, view->y2);