Added a new event macro ON_SIGHTING,

...which simulates a sighted event but in a more reliable manner.

data/core/macros/event-utils.cfg

@@ -195,3 +195,142 @@
         name=param[0]
     [/clear_variable]
 #enddef
+
+#define ON_SIGHTING ID SIGHTING_SIDE SIGHTED_FILTER ACTION_WML
+    # This is intended to be used when a regular sighted event can't be relied
+    # on (that'd be most of the time). This event triggers when a unit matching
+    # SIGHTED_FILTER is first seen by a unit of side SIGHTING_SIDE. This works
+    # whether the sighting happens due to moving, recruiting, recalling,
+    # attacking (in case DSU was on before the attack) or advancing. If none of
+    # those actions manage to "catch" the moment of sighting, then it will occur
+    # when the current side ends their turn.
+    #
+    # The 'unit' and 'second_unit' message speaker shortcuts as well as the
+    # auto-stored $unit and $second_unit should work normally.
+    #
+    # You need to provide a unique ID if you use several of these events in the
+    # same scenario. Otherwise it can be left empty.
+    #
+    # Only works if SIGHTING_SIDE has fog and/or shroud.
+    #
+    # Example:
+    #! {ON_SIGHTING () 1 side=2,3 (
+    #!     [message]
+    #!         speaker=unit
+    #!         message= _ "I can see a side $second_unit.side $second_unit.type|!"
+    #!     [/message]
+    #!     [message]
+    #!         speaker=second_unit
+    #!         message= _ "Oh my! I was seen by a side $unit.side $unit.type|!"
+    #!     [/message]
+    #! )}
+    #!
+    [event]
+        name=SIGHTED_{ID}_trigger_action_WML
+
+        {ACTION_WML}
+    [/event]
+
+    [event]
+        name=moveto,recruit,recall,attack,post advance,side turn
+        first_time_only=no
+
+        [filter]
+            side={SIGHTING_SIDE}
+
+            [or]
+                {SIGHTED_FILTER}
+            [/or]
+        [/filter]
+
+        [if]
+            [variable]
+                name=SIGHTED_{ID}_finished
+                not_equals=yes
+            [/variable]
+
+            [then]
+                [store_side]
+                    side={SIGHTING_SIDE}
+                    variable=stored_sighting_side
+                [/store_side]
+
+                [if]
+                    [have_unit]
+                        {SIGHTED_FILTER}
+
+                        [filter_vision]
+                            viewing_side={SIGHTING_SIDE}
+                        [/filter_vision]
+                    [/have_unit]
+
+                    [and]
+                        [variable]
+                            name=stored_sighting_side.fog
+                            boolean_equals=yes
+                        [/variable]
+
+                        [or]
+                            [variable]
+                                name=stored_sighting_side.shroud
+                                boolean_equals=yes
+                            [/variable]
+                        [/or]
+                    [/and]
+
+                    [then]
+                        [fire_event]
+                            name=SIGHTED_{ID}_trigger_action_WML
+
+                            [primary_unit]
+                                side={SIGHTING_SIDE}
+
+                                [filter_location]
+                                    [filter]
+                                        {SIGHTED_FILTER}
+
+                                        [not]
+                                            side={SIGHTING_SIDE}
+                                        [/not]
+                                    [/filter]
+
+                                    radius="$($this_unit.max_moves + 1)"
+                                [/filter_location]
+                            [/primary_unit]
+
+                            [secondary_unit]
+                                {SIGHTED_FILTER}
+
+                                [filter_vision]
+                                    viewing_side={SIGHTING_SIDE}
+                                [/filter_vision]
+                            [/secondary_unit]
+                        [/fire_event]
+
+                        [set_variable]
+                            name=SIGHTED_{ID}_finished
+                            value=yes
+                        [/set_variable]
+                    [/then]
+                [/if]
+
+                [clear_variable]
+                    name=stored_sighting_side
+                [/clear_variable]
+            [/then]
+
+            [else]
+                [allow_undo]
+                [/allow_undo]
+            [/else]
+        [/if]
+    [/event]
+
+    [event]
+        name=victory
+
+        [clear_variable]
+            name=SIGHTED_{ID}_finished
+        [/clear_variable]
+    [/event]
+#enddef