Zurg: adding to the Reference category

2019-11-23T09:58:22Z

adding to the Reference category

Zurg at 02:56, 3 August 2015

2015-08-03T02:56:24Z

DevliN: 1 revision imported: Restoring SC1 backup

2015-03-21T04:39:37Z

1 revision imported: Restoring SC1 backup

Zurg: /* Inner workings of the Wait action */

2015-03-09T22:44:12Z

‎Inner workings of the Wait action

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'''Wait blocks''' are [[trigger]]-related issues in ''[[StarCraft]]'' maps. They occur when the game tries to execute two Wait actions at the same time. Only one Wait action may be run at a time, so if a second is encountered, it is forcibly delayed until the first completes.

Wait blocks commonly occur when a map's triggers use both Waits and Wait-based [[hyper triggers]].

== Inner workings of the Wait action ==
Wait actions do more than just delaying other trigger actions by a given amount of milliseconds. When ''StarCraft'' runs a trigger for a player and encounters a Wait action, it takes the triggers that it has already processed for that player, and re-processes them all. ''Then'', the game delays the actions following the Wait. Consider a map with the following two triggers:

{{StarCraft Trigger
|description=Create a Marine every trigger cycle.
|players=*Player 1
|conditions=*Always
|actions=
*Create 1 [[Terran Marine (StarCraft)|Terran Marine]] at Anywhere for Player 1.
*Preserve trigger.
}}

{{StarCraft Trigger
|description=Display a message, wait a full second, and display another message.
|players=*Player 1
|conditions=*Always
|actions=
*Display for current player:Hello!
*Wait 1000 milliseconds.
*Display for current player:Goodbye!
*Preserve trigger.
}}

When those triggers are processed, ''StarCraft'' will do the following:
*Create a Terran Marine for Player 1.
*Display "Hello!" on Player 1's screen.
*Process the Wait action, by re-executing all Player 1 triggers.
**Create a Terran Marine for Player 1.
**Wait for a full second.
*Display "Goodbye!" on Player 1's screen.
That would be one trigger cycle.

== Wait blocks ==
The problems come when two Waits exist for the same player. Consider ''these'' triggers:

{{StarCraft Trigger
|description=TRIGGER 1. Create a Marine, wait a full second, and create another Marine.
|players=*Player 1
|conditions=*Always
|actions=
*Create 1 Terran Marine at Anywhere for Player 1.
*Wait 1000 milliseconds.
*Create 1 [[Terran SCV (StarCraft)|Terran SCV]] at Anywhere for Player 1.
*Preserve trigger.
}}

{{StarCraft Trigger
|description=TRIGGER 2. Display a message, wait a full second, and display another message.
|players=*Player 1
|conditions=*Always
|actions=
*Display for current player:Hello!
*Wait 1000 milliseconds.
*Display for current player:Goodbye!
*Preserve trigger.
}}

'''When ''StarCraft'' processes those triggers, it will do the following:'''
*First trigger round
*Create a Terran Marine for Player 1.
**Increase wait timer by 1000 (TRIGGER 1)
*Display "Hello!" on Player 1's screen.
**There is already a wait on the wait timer, so wait until it's over to continue
*Wait for a full second. (TRIGGER 1)
*Create a Terran SCV for Player 1.
**Increase wait timer by 1000 (TRIGGER 2)
*Next trigger round
*Create a Terran Marine for Player 1.
**There is already a wait on the wait timer, but it's from a previous round, so increase wait timer by 1000 (Trigger 1)
*Wait for 2 seconds. (TRIGGER 1+2)
*Next trigger round
*Create a Terran SCV for Player 1.
*Display for current player:Goodbye!

**The Wait action here cannot be processed, because the game is already processing a Wait action. This Wait and any remaining actions in this trigger (TRIGGER 1) will be delayed.
**Wait for a full second.
**Execute any delayed trigger actions.
***Process the delayed Wait from TRIGGER 1.
****There are no Player 1 triggers before TRIGGER 1.
****Wait for a full second.
***Create a Terran Marine for Player 1.
*Display "Goodbye!" on Player 1's screen.

'''That is a full trigger cycle. In simpler terms, here is what happens:'''
*Create a Terran Marine for Player 1.
*Display "Hello!"
*Wait for a full second. (TRIGGER 1)
*Create a Terran SCV for Player 1.
*Create a Terran Marine for Player 1.
*Wait for a full second. (TRIGGER 2)
*Wait for a full second. (TRIGGER 1)
**Essentially, the two waits are combined.
*Create a Terran SCV for Player 1.
*Display "Goodbye!"

In simple systems, this is often only a minor annoyance... But when large amounts of waits are used (as is the case when using Wait-based hyper triggers), the combined Wait time can cause a massive (or even infinitely long) wait block, completely breaking the map's triggers.

== Why do Waits behave this way? ==
The reason that previous triggers are re-processed when a Wait is run is to prevent problems in the trigger system. If triggers were not re-processed, then for the above example, there would be ''a full second where no triggers can run''. (This would translate to a full second in which no Marines are created.) In maps that need to detect things like unit locations and deaths, this would be a catastrophic delay. Any kind of map that requires precision or timing would end up completely broken. By re-processing the trigger list, ''StarCraft'' is able to delay trigger actions without breaking the trigger system. Wait blocks are simply an unanticipated problem in this system.

== Solutions ==
*When using Wait-based hyper triggers, set them up properly. Alternatively, switch to "complex" hyper triggers, which are (ironically) much easier to set up and maintain.
*Avoid situations where a player could end up running multiple Waits at once.
*Use different methods to keep track of time. Timers can use [[death counters]], countdown timers, the movement of a unit from one location to another, or even the burning and destruction of a badly-damaged [[Terran]] building (using the death counters or Extended Unit Deaths to detect certain values.)

== External links ==
*[http://www.youtube.com/watch?v=olYjMbmqj5g A YouTube video] illustrating how waits are processed, using some of the example triggers [[#Inner workings of the wait action|in this article]].

[[Category:StarCraft]]

← Older revision		Revision as of 09:58, 23 November 2019
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		+	[[Category:Reference]]

← Older revision		Revision as of 02:56, 3 August 2015
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−	'''Wait blocks''' are [[trigger]]-related issues in ''[[StarCraft]]'' maps. They occur when the game tries to execute two Wait actions at the same time. Only one Wait action may be run at a time, so if a second is encountered, it is forcibly delayed until the first completes.	+	'''Wait blocks''' are [[trigger]]-related issues in ''StarCraft'' maps. They occur when the game tries to execute two Wait actions at the same time. Only one Wait action may be run at a time, so if a second is encountered, it is forcibly delayed until the first completes.

	Wait blocks commonly occur when a map's triggers use both Waits and Wait-based [[hyper triggers]].		Wait blocks commonly occur when a map's triggers use both Waits and Wait-based [[hyper triggers]].

← Older revision	Revision as of 04:39, 21 March 2015
(No difference)

Wait blocks - Revision history

Zurg: adding to the Reference category

Zurg at 02:56, 3 August 2015

DevliN: 1 revision imported: Restoring SC1 backup

Zurg: /* Inner workings of the Wait action */