The ECM Tank Missile Deflection Behavior is Bugged

[MrS-ibra]

Prerequisites

• I have searched for similar issues and confirmed this is not a duplicate

Game Version

• Command & Conquer Generals
• Command & Conquer Generals: Zero Hour
• Other (please specify below)

Bug Description

When one or multiple ECM tanks are in place, missile deflection behavior becomes very erratic.
Instead of cleanly deflecting incoming missiles, the missiles dance around unpredictably and sometimes disappear without hitting anything.

Reproduction Steps

1. Build ECM tanks
2. Get opponent to build missile based units
3. Order enemy missile units to fire at your ECM tanks.
4. Missiles jitter, loop erratically, “dance” in midair, or disappear entirely without hitting anything.

Additional Context

Comparison:
retail
https://github.com/user-attachments/assets/36a9dbf5-1a93-48d6-ac37-febfefa44bd8

No retail (Bugged)
https://github.com/user-attachments/assets/1307f845-82a3-44ea-b6a4-d59f6cefa85b

[xezon]

I think we already have report(s) that cover ECM Deflection

[MrS-ibra]

I think we already have report(s) that cover ECM Deflection

Oh, is that about this exact ECM bug? I searched the tracker for “ECM” and didn’t see anything. From what I can tell this only started happening in the last couple months, so I figured it was new. If it’s already logged under a different name, then this can be closed.

[xezon]

I watched the video now. Which game client is that? If it is Generals Online client, then you need to retest in our client. If this was our client, then our Replay Check should have long caught that, because this would mismatch game state.

[MrS-ibra]

I watched the video now. Which game client is that? If it is Generals Online client, then you need to retest in our client. If this was our client, then our Replay Check should have long caught that, because this would mismatch game state.

This was initially reported and noticed on Generals Online then I tested on the SH clients, so both the videos I uploaded are on SH clients, one with retail compatibility and the other with no retail which Skyaero helped with

[Skyaero42]

I watched the video now. Which game client is that? If it is Generals Online client, then you need to retest in our client. If this was our client, then our Replay Check should have long caught that, because this would mismatch game state.

I provided @MrS-ibra with a build with the RETAIL_COMPATIBEL_CRC and RETAIL_COMPATIBLE_BUG disabled. So the effect is present in our build, just not in our 'normal' retail compatible builds.

[xezon]

Ok interesting. That narrows the search then.

[bobtista]

Could it have to do with the framerate decoupling? Also, do ECM tanks use countermeasure logic?

void MissileAIUpdate::setFramesTillCountermeasureDiversionOccurs( UnsignedInt frames )
{
	UnsignedInt now = TheGameLogic->getFrame();
	m_framesTillDecoyed = now + frames; 
}

[x64-dev]

This appears to be caused by 5ba1741