[PATCH] Unit attack instability

[zoot]

Steps to reproduce:

1. Start a match on the 'Combat Demo' scenario.

What happens: After a while, a group of your units in the left side of the screen enters an 'unstable' state where they begin attacking an enemy, then return to their previous position, then begin attacking again etc. in an infinite loop.

What I believe would be ideal: Either the unit should attack or not - not vacillate in indecision!

[mimo]

There is in fact an inconsistency for units in defensive stance like in this demo : the unit starts to attack, but is immediately stopped, so go back to its held position, then starts again to attack, etc

The fix is simple, but there are two possibilities and I'm not sure what is the wanted behaviour when in defensive stance : for such a stance, the attack is done in UnitAI.prototype.AttackEntityInZone and the stop of the attack in UnitAI.prototype.ShouldAbandonChase.

We can prevent it to attack (in cases where it will be stopped by ShouldAbandonChase) by replacing in AttackEntityInZone the line

			this.PushOrderFront("Attack", { "target": target, "force": false, "forceResponse": forceResponse });

by

			if (this.GetStance().respondChaseBeyondVision || this.CheckTargetIsInVisionRange(target))
                	{
				this.PushOrderFront("Attack", { "target": target, "force": false, "forceResponse": forceResponse });
				return true;
			}

Or we can prevent it from being stopped in ShouldAbandonChase by replacing the lines

	// Stop if we're in hold-ground mode and it's too far from the holding point
	if (this.GetStance().respondHoldGround)
	{
		if (!this.CheckTargetDistanceFromHeldPosition(target, iid, this.attackType))
			return true;
	}

	// Stop if it's left our vision range, unless we're especially persistent
	if (!this.GetStance().respondChaseBeyondVision)
	{
		if (!this.CheckTargetIsInVisionRange(target))
			return true;
	}

by

	// Stop if we're in hold-ground mode and it's too far from the holding point
	if (this.GetStance().respondHoldGround)
	{ 
		if (!this.CheckTargetDistanceFromHeldPosition(target, iid, this.attackType))
			return true;
	}
	// Stop if it's left our vision range, unless we're especially persistent
	else if (!this.GetStance().respondChaseBeyondVision)
	{
		if (!this.CheckTargetIsInVisionRange(target))
			return true;
	}

The first solution is may-be better.

[zoot]

Replying to Markus:

Did you forget to attach the patch?

[Markus]

mimo already suggested some code changes. The first one being prefered. It changes the behavior in the mentioned demo scenario.

[leper]

In 13502:

Fix inconsitency between AttackEntityInZone and ShouldAbandonChase for units in defensive stance. Patch by mimo. Fixes #1866.

[leper]

Thanks for the patch.