Index: trunk/src/data.h
===================================================================
--- trunk/src/data.h	(revision 688)
+++ trunk/src/data.h	(revision 689)
@@ -61,6 +61,7 @@
 
 	/* cache */
 	rnd_xform_mx_t mx;    /* drawin/rendering mx transformation; does not affect bbox */
+	double mx_sx, mx_sy, mx_rotdeg;
 };
 
 extern camv_design_t camv;
Index: trunk/src/draw.c
===================================================================
--- trunk/src/draw.c	(revision 688)
+++ trunk/src/draw.c	(revision 689)
@@ -27,6 +27,20 @@
 #include <librnd/hid/hid.h>
 #include "obj_any.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);*/
+}
+
 void camv_draw_layer(camv_layer_t *ly, rnd_hid_gc_t gc, const rnd_hid_expose_ctx_t *region, rnd_xform_t *xform_caller)
 {
 	camv_rtree_it_t it;
@@ -33,8 +47,11 @@
 	void *o;
 	rnd_xform_mx_t *mx = NULL;
 
-	if (ly->enable_mx)
+	if (ly->enable_mx) {
 		mx = &ly->mx;
+		ly->mx_rotdeg = mx_extract_rot(*mx);
+		mx_extract_scale(*mx, &ly->mx_sx, &ly->mx_sy);
+	}
 
 	for(o = camv_rtree_first(&it, &ly->objs, (camv_rtree_box_t *)&region->view); o != NULL; o = camv_rtree_next(&it)) {
 		camv_any_obj_t *obj = o;
Index: trunk/src/obj_arc.c
===================================================================
--- trunk/src/obj_arc.c	(revision 688)
+++ trunk/src/obj_arc.c	(revision 689)
@@ -42,7 +42,17 @@
 {
 	rnd_hid_set_line_cap(gc, rnd_cap_round);
 	rnd_hid_set_line_width(gc, obj->arc.thick);
-	rnd_render->draw_arc(gc, obj->arc.cx, obj->arc.cy, obj->arc.r, obj->arc.r, obj->arc.start, obj->arc.delta);
+	if (mx != NULL) {
+		camv_layer_t *ly = obj->arc.parent_layer;
+		rnd_coord_t cx = rnd_xform_x((*mx), obj->arc.cx, obj->arc.cy);
+		rnd_coord_t cy = rnd_xform_y((*mx), obj->arc.cx, obj->arc.cy);
+		double rx = obj->arc.r * ly->mx_sx, ry = obj->arc.r * ly->mx_sy;
+		double start= obj->arc.start - ly->mx_rotdeg, delta = obj->arc.delta;
+
+		rnd_render->draw_arc(gc, cx, cy, rx, ry, start, delta);
+	}
+	else
+		rnd_render->draw_arc(gc, obj->arc.cx, obj->arc.cy, obj->arc.r, obj->arc.r, obj->arc.start, obj->arc.delta);
 }
 
 static void camv_arc_bbox(camv_any_obj_t *obj)