Why doesn't TriggerRegisterFilterUnitEvent accept EVENT_UNIT_DEATH?

[Luashine]

Duplicating the hive thread here to track it: https://www.hiveworkshop.com/threads/whats-the-difference-between-triggerregister-filterunitevent-and-unitevent.364349/

What's the difference between TriggerRegister-FilterUnitEvent and -UnitEvent?

Hi there. See title. Jass/Lua, doesn't matter. The examples will be in Lua, but I would like to know what's the difference or an explanation for this behavior?

sameTrigger = CreateTrigger()

sheep = CreateUnit(Player(0), FourCC"nshe", -256, 0, 270.0)

TriggerRegisterUnitEvent(sameTrigger, sheep, EVENT_UNIT_DEATH) -- returns a new event

TriggerRegisterPlayerUnitEvent(sameTrigger, Player(0), EVENT_PLAYER_UNIT_DEATH, nil) -- returns a new event

TriggerRegisterFilterUnitEvent(sameTrigger, sheep, EVENT_UNIT_DEATH, nil) -- returns nil

Why does UnitEvent work with "EVENT_UNIT_DEATH", but FilterUnitEvent does not and returns null? Both register "EVENT_UNIT_LOADED" just fine.

For reference, the native declarations are:

native TriggerRegisterUnitEvent       takes trigger whichTrigger, unit whichUnit,           unitevent whichEvent                            returns event

native TriggerRegisterPlayerUnitEvent takes trigger whichTrigger, player whichPlayer, playerunitevent whichPlayerUnitEvent, boolexpr filter returns event

native TriggerRegisterFilterUnitEvent takes trigger whichTrigger, unit whichUnit,           unitevent whichEvent,           boolexpr filter returns event

[shuen4]

TriggerRegisterFilterUnitEvent use IsFilterUnitEvent
TriggerRegisterUnitEvent use IsUnitEvent & IsFilterUnitEvent

if it get filtered out then event will not create

[Luashine]

PurgeAndFire ended up doing the complete test himself there: https://www.hiveworkshop.com/threads/whats-the-difference-between-triggerregister-filterunitevent-and-unitevent.364349/

use IsUnitEvent & IsFilterUnitEvent

did you mean IsUnitEvent || IsFilterUnitEvent? It doesn't make sense otherwise, because TriggerRegisterUnitEvent is more permissive.

[shuen4]

the & there mean text and not bitwise operator and

code is if (!IsUnitEvent(whichUnitEvent) && !IsFilterUnitEvent(whichUnitEvent)) return NULL;

[shuen4]

//{ event_type      , version } // event_id
  { game            , 0     }   // 0 ~ 10
  { player          , 0     }   // 11 ~ 17
  { playerUnit      , 0     }   // 18 ~ 51
  { unit            , 0     }   // 52 ~ 59
  { filterUnit      , 0     }   // 60 ~ 88
  { widget          , 0     }   // 89 
  { unknown         , 0     }   // 90 ~ 117
  { unused          , 0     }   // 118 ~ 255
  { game            , 6021  }   // 256 ~ 259
  { unused          , 6021  }   // 260
  { player          , 6021  }   // 261 ~ 268
  { playerUnit      , 6021  }   // 269 ~ 277
  { unused          , 6021  }   // 278 ~ 285
  { filterUnit      , 6021  }   // 286 ~ 294
  { unused          , 6021  }   // 295 ~ 304
  { player          , 6071  }   // 305 ~ 307
  { playerUnit      , 6071  }   // 308
  { player          , 6071  }   // 309
  { game            , 6071  }   // 310
  { player          , 6071  }   // 311 ~ 313
  { unit            , 6071  }   // 314
  { playerUnit      , 6071  }   // 315
  { player          , 6081  }   // 316
  { game            , 6093  }   // 317
  { unit            , 6108  }   // 318
  { playerUnit      , 6108  }   // 319