[BUG] Snapped rails are slightly misplaced

[dvdvideo1234]

Describe the bug
Sometimes in certain cases, if the user tries to snap a track to already rotated and frozen track, a slight misplacement of the joint may be experienced leading to derailment and misplaced attachments. THIS IS NOT RELATED TO FLOAT MISPLACEMENTS

To Reproduce
Steps to reproduce the behavior:

1. Load gm_construct
2. Normal spawn PHX x16 track as points 1>2 to be water>wall
3. Snap 16x PHX track to point 1 of the spawned track

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots
How is it ghosted:

How it spawns:

Host machine (please complete the following information):

• OS type: Win
• OS version: Win7 SP1
• Gmod platform: PC
• Gmod branch: x64
• Gmod version: 2021.08.09
• Gmod instance: BOTH
• Tool version: 8.661

Additional context
base-DB: stSpawn.BPos, stSpawn.BAng ( Trace piece database entry )
trac-EN: stSpawn.TOrg, stSpawn.TAng ( trace entity positio/angle )
base-CA: stSpawn.BPos, stSpawn.BAng ( Values after calling ENT:LocalToWorld )
hold: stSpawn.HPnt, stSpawn.HOrg, stSpawn.HAng ( Holder piece database entry )
orgn: stSpawn.OPos, stSpawn.OAng ( Origin/angin angle for matrix manipulations )
spawn: stSpawn.SPos, stSpawn.SAng ( Calculated spawn position and angle )

trigger
base-DB:	2029.797363 0.000133 12.548828	0.000 0.000 0.000
trac-EN:	-19.115608 -2153.927002 -147.223434	0.000 90.000 0.000
base-CA:	-19.115435 -124.129639 -134.674606	-0.000 90.000 0.000
hold:	-370.036865 -0.000000 12.548828	-370.036865 -0.000000 12.548828	0.000 -180.000 0.000
orgn:	-19.115435 -124.129639 -134.674606	-0.000 90.000 0.000
spawn:	-19.115379 245.907257 -147.223434	-0.000 90.000 0.000
1:	-19.115379 245.907257 -147.223434	-0.000 90.000 0.000
2:	-19.115379 245.907257 -147.223434	-0.000 90.000 0.000
base-DB:	2029.797363 0.000133 12.548828	0.000 0.000 0.000
trac-EN:	-19.115608 -2153.927002 -147.223434	0.000 89.995 0.000
base-CA:	-18.920891 -124.129639 -134.674606	-0.000 89.994 0.000
hold:	-370.036865 -0.000000 12.548828	-370.036865 -0.000000 12.548828	0.000 -180.000 0.000
orgn:	-18.920891 -124.129639 -134.674606	-0.000 89.994 0.000
spawn:	-18.885368 245.907227 -147.223434	-0.000 89.994 0.000
base-DB:	2029.797363 0.000133 12.548828	0.000 0.000 0.000
trac-EN:	-19.115608 -2153.927002 -147.223434	0.000 89.995 0.000
base-CA:	-18.920891 -124.129639 -134.674606	-0.000 89.994 0.000
hold:	-370.036865 -0.000000 12.548828	-370.036865 -0.000000 12.548828	0.000 -180.000 0.000
orgn:	-18.920891 -124.129639 -134.674606	-0.000 89.994 0.000
spawn:	-18.885368 245.907227 -147.223434	-0.000 89.994 0.000
base-DB:	2029.797363 0.000133 12.548828	0.000 0.000 0.000
trac-EN:	-19.115608 -2153.927002 -147.223434	0.000 89.995 0.000
base-CA:	-18.920891 -124.129639 -134.674606	-0.000 89.994 0.000
hold:	-370.036865 -0.000000 12.548828	-370.036865 -0.000000 12.548828	0.000 -180.000 0.000
orgn:	-18.920891 -124.129639 -134.674606	-0.000 89.994 0.000
spawn:	-18.885368 245.907227 -147.223434	-0.000 89.994 0.000
3:	-18.885368 245.907227 -147.223434	-0.000 89.994 0.000

[dvdvideo1234]

In the rotator tool copy angle is retrieved from the server into the convars as 89.994 instead of 90.0. Consider the following case where the angle test is a local variable and stSpawn.TAng uses the assignment Set method:

        stSpawn.TOrg:Set(trEnt:GetPos())
        stSpawn.TAng:Set(trEnt:GetAngles()); --SnapAngle(stSpawn.TAng, 15)
        SetVector(stSpawn.TPnt, trPOA.P)
        stSpawn.TPnt:Rotate(stSpawn.TAng)
        stSpawn.TPnt:Add(stSpawn.TOrg)
  -- Found the active point ID on trEnt. Initialize origins
  SetVector(stSpawn.BPos, trPOA.O) -- Read origin
  SetAngle (stSpawn.BAng, trPOA.A) -- Read angle
  if(trEnt:GetNetworkedBool("trackassembly_debugen")) then
    print("base-DB:", stSpawn.BPos, stSpawn.BAng)
    print("trac-EN:", stSpawn.TOrg, stSpawn.TAng)
    local test = trEnt:GetAngles()
    print("SP-hash", test.p, test.y, test.r)
    print("SP-intg", test[1], test[2], test[3])
  end

trac-EN:    922.957764 702.231873 -31.192244    0.000 90.000 0.000
SP-hash    0    89.999984741211    0
SP-intg    0    89.999984741211    0

[dvdvideo1234]

There has to be spawn angles correction for the first ( hit-normal ) track after the matrix manipulation:

trigger
1:from	0.000 -90.000 0.000
1:from	0	-90	0
1:from	0	-90	0
1:uang	0.000 -90.000 0.000
1:uang	0	-90	0
1:uang	0	-90	0
1:bang	0.000 -90.000 0.000
1:bang	0	-90	0
1:bang	0	-90	0
1:origin	0.000 -90.000 0.000
1:origin	0	-90	0
1:origin	0	-90	0
2:origin	0.000 -90.000 0.000
2:origin	0	-90	0
2:origin	0	-90	0
hold:	-370.037994 0.000000 12.548828	-370.037994 0.000000 12.548828	0.000 -180.000 0.000
orgn:	935.351257 1924.607910 -18.643417	0.000 -90.000 0.000
spawn:	935.351196 1554.569946 -31.192245	-0.000 -90.000 0.000
2:spn	-0.000 -90.000 0.000
2:spn	-0	-90	0
2:spn	-0	-90	0
2:to	-0.000 -90.000 0.000
2:to	-0	-90	0
2:to	-0	-90	0
normal:	935.351196 1554.569946 -31.192245	-0.000 -90.000 0.000
TA-angl	-0.000 -90.000 0.000
TA-hash	-0	-90	0
TA-intg	-0	-90	0
TA-aget	-0.000 -90.000 0.000

[dvdvideo1234]

Closed in #32