fix in trace and app config

swissmx.py

@@ -410,10 +410,6 @@ class WndSwissMx(QMainWindow, Ui_MainWindow):
     #bm.setTransform(tr)  # assign transform
     grp.addItem(obj)
 
-    #--- camera tracong images ---
-    self._goTrace=grp=pg.ItemGroup() # the transformation is the same as for tracked objects
-    grp.setZValue(-20) #lower than other objects
-    self.vb.addItem(grp)
 
 
 
@@ -1079,16 +1075,7 @@ class WndSwissMx(QMainWindow, Ui_MainWindow):
 
 
         #create trace
-        img=pg.ImageItem(self._goImg.image)
-        img.setZValue(100)
-        trImg=self._goImgGrp.transform()
-        trTrk=self._goTracked.transform()
-
-        tr=trImg*trTrk.inverted()[0] #TODO: check if oder correct !!!
-        #tr.scale(.5,.5)
-        img.setTransform(tr)
-
-        self._goTrace.addItem(img)
+        self.add_camera_trace()
 
         _log.debug(f'dist to beam ({pFix[0]:>0.6g} {pFix[1]:>0.6g}mm)')
         fx_motor=self.tweakers["fast_x"]
@@ -1096,9 +1083,6 @@ class WndSwissMx(QMainWindow, Ui_MainWindow):
 
         fx_motor.move_rel(pFix[0])
         fy_motor.move_rel(pFix[1])
-        self._goTrace.setTransform(self._goTracked.transform())
-
-
 
         #fx_motor.move_abs(fx_motor.get_val()+pFix[0])
         #fy_motor.move_abs(fy_motor.get_val()+pFix[1])
@@ -1280,6 +1264,7 @@ class WndSwissMx(QMainWindow, Ui_MainWindow):
     fy=twk_fy.get_val()
     try:
       grp=self._goTracked
+      grpTrc=self._goTrace
       zoom_old,fx_old,fy_old=grp._state
     except AttributeError: # at initialization
       self._goTracked=grp=pg.ItemGroup()
@@ -1287,12 +1272,17 @@ class WndSwissMx(QMainWindow, Ui_MainWindow):
       self.vb.addItem(grp)
       grp._state=(zoom,fx,fy)
       zoom_old=fx_old=fy_old=None
+
+      #--- camera tracing images ---
+      self._goTrace=grpTrc=pg.ItemGroup() # the transformation is the same as for tracked objects
+      grpTrc.setZValue(-20) #lower than other objects
+      self.vb.addItem(grpTrc)
+
     _log.debug(f"zoom:{zoom_old}->{zoom} fx:{fx_old}->{fx} fy:{fy_old}->{fy}")
     if zoom_old!=zoom:
       geo.interp_zoom(zoom)
 
     bm=self._goBeamMarker
-    grp=self._goTracked
     opt_ctr=geo._opt_ctr
     A=np.asarray(geo._pix2pos.I)
     # trf=cfg.value(AppCfg.GEO_CAM_TRF)
@@ -1304,6 +1294,21 @@ class WndSwissMx(QMainWindow, Ui_MainWindow):
                  A[1, 0], A[1, 1], 0,
                  p[0], p[1], 1)  # translate dx,dy
     grp.setTransform(tr)
+    grpTrc.setTransform(tr)
+
+  def add_camera_trace(self):
+    # add up to tracelen image when moveing motors to new positions
+    tracelen=4
+    img=pg.ImageItem(self._goImg.image)
+    trImg=self._goImgGrp.transform()
+    trTrk=self._goTracked.transform()
+
+    tr=trImg*trTrk.inverted()[0]  # TODO: check if oder correct !!!
+    img.setTransform(tr)
+    self._goTrace.addItem(img)
+    cld=self._goTrace.childItems()
+    if len(cld) > tracelen:
+      self.vb.removeItem(cld[0])
 
   def cb_modify_app_param(self):
     wnd=WndParameter(self)