prowler 'microteleport' when uncloaked due to shot

[ghost]

Given a cloaked prowler last seen in position A, when it is uncloaked due to hit at position B, prowler either

• takes a moment to appear in position B
• briefly appears for one/two frames in position A before teleporting to position B

In either case, no unstealth transition runs, IIRC such a transition existed in real server

Looks like:

https://github.com/steamroller-airmash/airmash-server/blob/5e096b37aaf6a4b7cc6357a64b945fe466035f10/server/src/systems/specials/prowler/destealth_on_fire.rs#L44-L51

We tell the prowler that it is unstealthed, but we do not tell any other visible plane. I think this means on next random position update, prowler will suddenly reappear.

I'm not sure if it explains why the teleport happens. I'd expect client wants something like one PLAYER_UPDATE prior to EVENT_UNSTEALTH

Will try implementing this for destealth_on_fire / destealth_on_hit and see how it goes

[steamroller-airmash]

IIRC the unstealth transition only happened when the player unstealthed by choice. Even then, I don't recall if other players saw it or if it. Here is a video showing derp unstealthing without the transition when firing.

I think the way it worked on the original server was like this:

• Only the player who uncloaked gets the EVENT_UNSTEALTH packet
• Everyone else sees it as a PLAYER_UPDATE packet that happens at the same time.

This doesn't appear to be correct since we have the teleporting occurring. Unfortunately, without access to the original server I'm at a bit of a loss as to what are the correct packets here. We will probably have to reverse-engineer it from what behaviour we expect and what packets need to be passed to the client to get that.

[congratulatio]

Looking at some packet captures from the original server, I think you are correct, the difference is the PLAYER_UPDATE packet.

When the prowler fired, other players would see two identical PLAYER_UPDATE packets followed by a PLAYER_FIRE packet, all with the same clock:

PLAYER_UPDATE (12) {
    "clock":1387168521,
    "id":36670,
    "keystate":5,
    "upgrades":0,
    "posX":-1589.59375,
    "posY":-1415.990234375,
    "rot":1.633758544921875,
    "speedX":4.27978515625,
    "speedY":1.3909912109375}

PLAYER_UPDATE (12) {
    "clock":1387168521,
    "id":36670,
    "keystate":5,
    "upgrades":0,
    "posX":-1589.59375,
    "posY":-1415.990234375,
    "rot":1.633758544921875,
    "speedX":4.27978515625,
    "speedY":1.3909912109375}

PLAYER_FIRE (13) {
    "clock":1387168521,
    "id":36670,
    "energy":0.25098039215686274,
    "energyRegen":0.006,
    "projectiles":[
       {"id":38313,
        "type":7,
        "posX":-1554.5,
        "posY":-1413.75,
        "speedX":5.9075927734375,
        "speedY":0.372314453125,
        "accelX":0.069854736328125,
        "accelY":0.00439453125,
        "maxSpeed":7.0001220703125}
        ]}

On the new server, the last PLAYER_UPDATE sent for the prowler, and thus its last known position, is prior to EVENT_STEALTH:

PLAYER_UPDATE (12) {
    "clock":121264357,
    "id":105,
    "keystate":9,
    "upgrades":0,
    "posX":241.658203125,
    "posY":-1904.150390625,
    "rot":0.35400390625,
    "speedX":-0.38818359375,
    "speedY":-4.4830322265625}

EVENT_STEALTH (43) {
    "id":105,
    "state":true,
    "energy":0,
    "energyRegen":0.008}

PLAYER_FIRE (13) {
    "clock":121422715,
    "id":105,
    "energy":0.011764705882352941,
    "energyRegen":0.008,
    "projectiles":[
       {"id":56,
        "type":7,
        "posX":442.5,
        "posY":-1967,
        "speedX":-4.1461181640625,
        "speedY":-0.1727294921875,
        "accelX":-0.069915771484375,
        "accelY":-0.002899169921875,
        "maxSpeed":6.99951171875}
        ]}

PLAYER_UPDATE (12) {
    "clock":121424357,
    "id":105,
    "keystate":9,
    "upgrades":0,
    "posX":477.162109375,
    "posY":-1961.130859375,
    "rot":4.8089599609375,
    "speedX":-0.73974609375,
    "speedY":4.4384765625}

I think what's happening is because PLAYER_FIRE causes the prowler to become visible, a mini-teleport occurs between the positions in the PLAYER_UPDATE packets immediately before EVENT_STEALTH and just after PLAYER_FIRE.