Ok, so to demonstrate what I would expect from a transX that supports deep space manoeuvres(DSM), I've come up with a simple Earth - Venus - Earth sling scenario.
Code:
BEGIN_DESC
END_DESC
BEGIN_ENVIRONMENT
System Sol
Date MJD 51981.6440262641
END_ENVIRONMENT
BEGIN_FOCUS
Ship GL-01
END_FOCUS
BEGIN_CAMERA
TARGET GL-01
MODE Cockpit
FOV 60.00
END_CAMERA
BEGIN_HUD
TYPE Surface
END_HUD
BEGIN_MFD Left
TYPE User
MODE TransX
Ship GL-01
FNumber 4
Int 1
Orbit True
Vector -6181552.6882 -2312628.92594 -428125.160126
Vector -1562.7336384 5193.97069794 -5562.24935739
Double 3.98600439969e+014
Double 51981.6440246
Handle Earth
Handle NULL
Handle NULL
Select Target
0 Escape
Autoplan
0 0
Plan type
0 0
Plan
0 1
Plan
0 0
Plan
0 0
Select Minor
0 None
Manoeuvre mode
0 0
Auto-Center™
0 0
Base Orbit
0 0
Prograde vel.
1 0
Man. date
1 51981.6440243
Outward vel.
1 0
Ch. plane vel.
1 0
Intercept with
0 0
Orbits to Icept
0 0
Graph projection
0 0
Scale to view
0 0
Advanced
0 0
Pe Distance
1 6577819.54864
Ej Orientation
1 0.520108117094
Equatorial view
0 0
Finvars
Finish BaseFunction
Int 2
Orbit False
Handle Sun
Handle Earth
Handle Venus
Select Target
0 Venus
Autoplan
0 0
Plan type
0 2
Plan
0 0
Plan
0 0
Plan
0 1
Select Minor
0 None
Manoeuvre mode
0 0
Auto-Center™
0 0
Base Orbit
0 1
Prograde vel.
1 0
Man. date
1 51981.6438786
Outward vel.
1 0
Ch. plane vel.
1 0
Intercept with
0 0
Orbits to Icept
0 0
Graph projection
0 0
Scale to view
0 0
Advanced
0 0
Prograde vel.
1 -4064.22738622
Eject date
1 51981.6014162
Outward vel.
1 0
Ch. plane vel.
1 0
Finvars
Finish BaseFunction
Int 4
Orbit True
Vector -840421171.862 1353764235.44 -5916842353.1
Vector 1297.75776923 -2081.68265354 8622.14444691
Double 3.2485863e+014
Double 52145.741176
Handle Venus
Handle NULL
Handle NULL
Select Target
0 Escape
Autoplan
0 0
Plan type
0 1
Plan
0 0
Plan
0 1
Plan
0 0
Select Minor
0 None
Manoeuvre mode
0 0
Auto-Center™
0 0
Base Orbit
0 0
Prograde vel.
1 0
Man. date
1 51981.6438728
Outward vel.
1 0
Ch. plane vel.
1 0
Intercept with
0 0
Orbits to Icept
0 0
Graph projection
0 0
Scale to view
0 0
Advanced
0 0
View Orbit
0 0
Finvars
Finish BaseFunction
Int 3
Orbit True
Vector 23912265865 -170892517.741 105086439570
Vector -33435.5373775 676.315021139 16353.3732053
Double 1.32712764814e+020
Double 52153.6365112
Handle Sun
Handle Venus
Handle Earth
Select Target
0 Earth
Autoplan
0 0
Plan type
0 2
Plan
0 0
Plan
0 0
Plan
0 2
Select Minor
0 None
Manoeuvre mode
0 0
Auto-Center™
0 0
Base Orbit
0 0
Prograde vel.
1 0
Man. date
1 51981.6438091
Outward vel.
1 0
Ch. plane vel.
1 0
Intercept with
0 0
Orbits to Icept
0 0
Graph projection
0 0
Scale to view
0 0
Advanced
0 0
Velocity.
1 0
Outward angle
1 1.01532818812
Inc. angle
1 0.269548649678
Inherit Vel.
0 0
Eject date
1 52153.6365112
Finvars
Finish BaseFunction
END_MFD
BEGIN_MFD Right
TYPE User
MODE TransX
END_MFD
BEGIN_SHIPS
GL-01:DeltaGlider
STATUS Orbiting Earth
RPOS -6181782.20 -2311865.76 -428942.40
RVEL -1561.482 5194.440 -5562.162
AROT 29.44 52.32 166.37
VROT -0.11 -0.05 0.09
AFCMODE 7
PRPLEVEL 0:1.000000 1:1.000000
NAVFREQ 402 94 0 0
XPDR 0
GEAR 1 1.0000
AAP 0:0 0:0 0:0
END
END_SHIPS
BEGIN_ExtMFD
END
The first stage would be the same as any normal eject burn to another planet. Select Target Planets/Moons --> Escape --> FWD (Forward)
Then at Stage 2, . Select Target Planets/Moons --> Venus, then I've set the Prograde vel. value to -4.064k to encounter venus. FWD to move to the next stage.
At stage 3, Target Planets/Moons --> Escape then FWD to move to the next stage.
Now at stage 4, Target Planets/Moons --> Earth, then I press VW to enter Sling Direct mode. It is this view where we should be able to set up the DSM. There are already 5 options in this view i.e. 'Inherit Vel.', 'Inc. angle', 'Outward angle', 'Velocity.', 'Eject date'. Now we add another option in this view, which would be 'Manoeuvre mode', the same 'Manoeuvre mode' which we use for mid course corrections when we are coasting through space and in this scenario, the 'Manoeuvre mode' can be found in stage 1.
So now in Stage 4 in sling direct view, we find 'Manoeuvre mode' along with the 5 other options. It is set to 'Off' by default, similar to how 'Inherit Vel.' is set to Yes by default. When we set the 'Manoeuvre mode' to On, we find the same options which we see during mid course corrections namely 'Ch. plane vel.', 'Outward vel.', Man. date', 'Prograde vel.', 'Base orbit ++ Updates'. No Auto-Center option in this case because this is a later stage, not our current stage. Now, we have 2 dates in that view, which are 'Eject date.' & our added 'Man. date'. The 'Eject date.' in transX already can't be changed from that stage, we leave it that way. But the 'Man. date' is the one which would indicate the date of our DSM.
Now, in the image above, you can see that my encounter at venus occurs at 52153 & my encounter at earth occurs at 52473. Which means, between those 2 dates, I'm just coasting through space. Now let's say I input a date, 'Man date' 52313 in TransX. During that date, the ship would be somewhere near the apoapsis of it's orbit.
Now, as I adjust the 'Man date', TransX should show me exactly where I would be in my orbit at that date, using a point as an indicator as shown in the image above. Once that's set, I should be able to add 'Ch. plane vel.', 'Outward vel.', 'Prograde vel.' & see it's effects, just like any normal 'Manoeuvre mode' & this will enable me to perform the DSM. (Of course, this would also mean a Target view in Stage 4 when we press VW, but that should activate only after we have entered that stage i.e. We have left venus & our original stage 4 has become our stage 1. Now we can also have the Auto Center option at this point).
Once 'Manoeuvre mode' is turned On, we should be able to change the values of not only 'Ch. plane vel.', 'Outward vel.', 'Prograde vel.' & 'Man date' but also the usual 'Inherit Vel.', 'Inc. angle', 'Outward angle', 'Velocity.' that already come with the sling direct view.
One other thing to note is that the 'Man date' can have a minimum value equal to the 'Eject date' which would be 52153 in this case which is a constant in that stage & maximum value would be the date of encounter, which would be 52473 in this case, however, as this encounter date changes depending on the values of 'Ch. plane vel.', 'Outward vel.', 'Prograde vel.', 'Inc. angle', 'Outward angle', this upper limit of 'Man date' wouldn't be a fixed one, it should change as the user changes the other 5 parameters & should always be equal to the encounter date, meaning the user shouldn't be able to set the Man date beyond the target encounter date.
This is how I think DSM should be incorporated in transX. If anyone else has a better idea or something to add to this, please feel free to post in this thread. Thank you for your interest in implementing this feature, enjo.