Add normalize button, no auto attenuate when subtracting storage

nanovna.h

@@ -206,6 +206,7 @@ int GetAverage(void);
 void  set_storage(void);
 void  set_clear_storage(void);
 void  set_subtract_storage(void);
+void  toggle_normalize(void);
 void toggle_waterfall(void);
 void set_mode(int);
 int GetMode(void);

sa_core.c

@@ -423,6 +423,20 @@ void set_subtract_storage(void)
   dirty = true;
 }
 
+
+void toggle_normalize(void)
+{
+  if (!setting.subtract_stored) {
+    for (int i=0; i<POINTS_COUNT;i++)
+      stored_t[i] = actual_t[i];
+    setting.subtract_stored = true;
+  } else {
+    setting.subtract_stored = false;
+  }
+  dirty = true;
+}
+
+
 extern float peakLevel;
 void set_actual_power(float o)
 {
@@ -1616,7 +1630,7 @@ again:
     redraw_request |= REDRAW_CAL_STATUS;
   }
 
-  if (!in_selftest && setting.mode == M_LOW && setting.auto_attenuation && max_index[0] > 0) {  // Auto attenuate
+  if (!in_selftest && setting.mode == M_LOW && setting.auto_attenuation && max_index[0] > 0 && !setting.subtract_stored) {  // Auto attenuate
     setting.atten_step = false;     // No step attenuate in low mode auto attenuate
     float old_attenuate = get_attenuation();
     float actual_max_level = actual_t[max_index[0]] - old_attenuate;

ui_sa.c

@@ -893,6 +893,9 @@ static void menu_storage_cb(int item, uint8_t data)
       set_subtract_storage();
       break;
     case 3:
+      toggle_normalize();
+      break;
+    case 4:
       toggle_waterfall();
       break;
   }
@@ -1460,7 +1463,8 @@ static const menuitem_t menu_display[] = {
   { MT_CALLBACK,0,              "\2STORE\0TRACE",   menu_storage_cb},
   { MT_CALLBACK,1,              "\2CLEAR\0STORED",  menu_storage_cb},
   { MT_CALLBACK,2,              "\2SUBTRACT\0STORED",menu_storage_cb},
-  { MT_CALLBACK,3,              "WATERFALL",        menu_storage_cb},
+  { MT_CALLBACK,3,              "NORMALIZE",        menu_storage_cb},
+  { MT_CALLBACK,4,              "WATERFALL",        menu_storage_cb},
   { MT_KEYPAD,  KM_SWEEP_TIME,  "\2SWEEP\0TIME",    NULL},
 
   { MT_CANCEL, 0,           "\032 BACK", NULL },
@@ -1656,10 +1660,13 @@ static void menu_item_modify_attribute(
     if (item ==1 && setting.show_stored){
       mark = true;
     }
-    if (item == 3 && setting.subtract_stored){
+    if (item == 3 && setting.subtract_stored && setting.show_stored){
+      mark = true;
+    }
+    if (item == 4 && setting.subtract_stored && !setting.show_stored){
       mark = true;
     }
-    if (item == 4 && get_waterfall()){
+    if (item == 5 && get_waterfall()){
       mark = true;
     }
 #ifdef __SPUR__