Get client eye position

[87andrewh]

Higher goal I would like an Entity.EyePosition() function that accurately returns player eyes' Z coordinates, even when jumping or in the middle of the duck or un-duck animation. I suspect that IsDucking() is not accurate enough for my purposes.

Describe the solution you'd like In SourceMod, I use GetClientEyePosition(), which is accurate. I also think cl_showpos returns an accurate location.

Describe alternatives you've considered None.

Additional context I don't need the position to be extremely accurate in the XY plane, as I don't think there is a simple native way to access precise eye locations for both CT and T models in all animations. But an accurate Z should be obtainable.

[markus-wa]

Would be a nice feature.

Here's some notes, either for my future self or whoever want's to implement it.

SM's GetClientEyePosition() seems to be based on CServerGameClients->ClientEarPosition:

• https://github.com/alliedmodders/sourcemod/blob/4bebdc18a2e4820b234a85c3a1e38eb868a84bf2/extensions/sdktools/vnatives.cpp#L696-L718
• https://github.com/ValveSoftware/source-sdk-2013/blob/master/sp/src/game/server/gameinterface.cpp#L3089-L3102
• https://sourcegraph.com/github.com/ValveSoftware/source-sdk-2013@0d8dceea4310fde5706b3ce1c70609d72a38efdf/-/blob/mp/src/game/shared/baseentity_shared.cpp#L132-136
• https://sourcegraph.com/github.com/ValveSoftware/source-sdk-2013@0d8dcee/-/blob/mp/src/game/client/c_baseentity.cpp#L1707-1712
• https://sourcegraph.com/github.com/ValveSoftware/source-sdk-2013@0d8dceea4310fde5706b3ce1c70609d72a38efdf/-/blob/mp/src/game/client/c_baseentity.cpp#L4317-4394
• https://sourcegraph.com/github.com/ValveSoftware/source-sdk-2013@0d8dceea4310fde5706b3ce1c70609d72a38efdf/-/blob/mp/src/game/shared/baseentity_shared.cpp#L158-161

so it looks like it's C_BaseEntity::CalcAbsolutePosition() + localdata.m_vecViewOffset

not sure if this bit here is needed or not: https://github.com/alliedmodders/sourcemod/blob/4bebdc18a2e4820b234a85c3a1e38eb868a84bf2/extensions/sdktools/vnatives.cpp#L711-L715 < it's not needed

[87andrewh]

"not sure if this bit here is needed or not"

The highlighted code writes the position by reference. Without it, GetClientEyePosition() would do nothing.

[markus-wa]

It also seems to do some translation with LocalToPhysAddr() (and sp_ftoc?) Which I didn't look into yet.

[87andrewh]

Oh yeah, SourcePawn is weird. All types are converted to and passed as cell_t, which is int32. sp_ftoc() encodes floats as cell_t. pContext->LocalToPhysAddr(params[2], &addr) links params[2] to &addr, allowing you to edit params[2] through addr, which is the way that information is passed back to the caller.

For some context, a SourcePawn script calls GetClientEyePosition(), which is C++ code. GetClientEyePosition() returns information to the the SourcePawn script by editing the params by reference.

I actually don't think you need to worry too much about SourcePawn details, as it's a modding framework built on top of Source. The demo system should just hook Source stuff directly.

[markus-wa]

Ahh makes sense, cheers for the explanation!

[billfreeman44]

Maybe this helps? https://github.com/saul/demofile/discussions/290

[markus-wa]

Interesting thread @billfreeman44

I think what we should probably do as a quick win is expose something like EyeHeightOffset(). Then let users do the calc manually.

Calling into source engine code is probably out of scope for this project.

I guess in the meantime people can just use good old Player.Entity.PropertyValueMust(....

[markus-wa]

or we actually may get away with PositionEyes() and just Position() + m_vecViewOffset[2]

[markus-wa]

finally got around to this (really should have done so sooner considering how easy it turned out to be)

we now have Player.PositionEyes()

:partying_face: