Simulating new functions
I've tried creating a custom "function" that can be called by other scripts. The basic approach I took was to make the function a quest script, and have the calling script call the function via |StartQuest function_quest|. Ex:
I have a quest called testfunc that is initially disabled and contains the following script:
scn testfuncscript float param1 float param2 float result begin GameMode Message "start func", 1 set result to param1 + param2 Message "end func: %.0f", result, 1 StopQuest testfunc end
In another script, I call this "function":
scn testscript float r begin OnActivate Message "before call", 1 set testfunc.param1 to 10 set testfunc.param2 to 20 StartQuest testfunc set r to testfunc.result Message "after call: %.0f", r, 1 end
However, the above code doesn't work. The order of the output illustrates why:
before call after call: 0 start func end func: 30
This is what it should be:
before call start func end func: 30 after call: 30
The problem is that the calling script doesn't wait for the function script to execute, and instead the function script is delayed until after the calling script finishes executing.
So is there any way that can bypass this problem without resorting to nasty "wait for the other script to finish" hacks? (I could make the calling script have a GameMode block that would repeatly check when the function finishes executing, but that would be a serious PITA.) I suspect this same problem would've arisen if I had tried creating a function script by attaching it to a persistent object instead of a quest (and calling it via the Activate function).
--Maian 03:59, 18 April 2006 (EDT)
I'm just kind of brainstorming here, but you might try making a quest, marked "Allow repeated stages" so you can call the stages repeatedly, and make (say) stage 10 be your "function". Quest stage results are executed immediately, while the current script is processing, so you wouldn't have to wait for the results.
Keep your variables in your quest script. In stage 10 results, you'd have:
Message "start func", 1 set testfunc.result to testfunc.param1 + testfunc.param2 Message "end func: %.0f", testfunc.result, 1
To call this function, you'd do the following:
scn testscript float r begin OnActivate Message "before call", 1 set testfunc.param1 to 10 set testfunc.param2 to 20 setstage testfunc 10 ; call the "function" set r to testfunc.result Message "after call: %.0f", r, 1 end
I think this should work (I haven't tried it).
--Kkuhlmann 14:02, 18 April 2006 (EDT)
I've been doing this for awhile now with OnActivate functions placed on activators. The reference you use to activate it acts as a parameter to tell it how to act. Then when that function is done it activates the calling object to let it know that it is finished and it is time to process the results.
So for instance
scn ActivateFunction
ref incoming
begin OnActivate
set incoming to GetActionRef
if (incoming == CallingScriptRef.Me)
set CallingScriptRef.Value to CallingScriptRef.Value + 3
CallingScriptRef.Activate CallingScriptRef.ActivateFunctionRef 1
return
endif
end
scn CallingScript
ref Me
ref ActivateFunctionRef
long Value
ref incoming
begin OnLoad
set Me to GetSelf
set Value to 0
Message "I am storing a value of %.0f", Value, 1
end
begin OnActivate
set incoming to GetActionRef
if (incoming == ActivateFunctionRef)
Message "Now I am storing a value of %.0f", Value, 1
return
endif
ActivateFunctionRef.Activate Me 1
end
This removes the need for a game mode block and allows function passing (or setting in a persistent reference). I've used this quite successfully for some cool stuff I'm finishing the testing on. --Tegid 14:44, 18 April 2006 (EDT)
After some experimentation, I've verified that making the function script an object script and attaching it to a dummy object (in activator called testfunc in my case), it works. That is, it satisfies the following conditions:
- It can be called (via |testfunc.Activate player, 1|).
- The function is executed immediately rather than after the script that called it.
- It can be called even in places where the dummy object isn't at, e.g. I placed the dummy object inside an interior cell and called it in an exterior cell. This was what I was most worried about with this approach - that the function would only work if the dummy object is in the same area. I haven't tested this extensively, so it may be the case that it works only because the dummy object is still in memory, but I suspect that's not the case.
Tegid, in your example, the called function apparently needs a reference to the script calling it, which defeats the purpose of making the function generic (after all, the main reason for creating a new function is to share code between 2+ functions). Maybe if your script just checked if incoming.Me was set and just used incoming rather than CallingScriptRef, it could work generically.
Kkuhlmann, I haven't tried your method yet, but I'm post an update once I do so.
Thanks for all the help! --Maian 21:49, 18 April 2006 (EDT)
Kkuhlmann's solution also worked.
For reference, here's my dummy object + activate script solution:
On a dummy object:
scn testfuncobjscript
float param1
float param2
float result
begin OnActivate
if IsActionRef Player != 1
Message "start func", 1
set result to param1 + param2
Message "end func: %.0f", result, 1
else
Activate
endif
end
Calling script:
scn testobjscript float r ref self begin Onload set self to GetSelf end begin OnActivate Message "before call", 1 set testfuncref.param1 to 10 set testfuncref.param2 to 20 testfuncref.Activate self, 1 set r to testfuncref.result Message "after call: %.0f", r, 1 end
--Maian 01:47, 19 April 2006 (EDT)
The CallingScriptRef is just your single point of entry into the set of scripted functions. It is a persistent reference Activator like your testfuncref. Also, it has not been my experience that Activate calls interrupt the flow of script parsing. I was under the impression that the Activate call really just sets a bit so that when that script is reached, the OnActivate block is executed. --Tegid 11:07, 19 April 2006 (EDT)
I love the solution kkuhlmann has written! This is by far the best idea for immediately executing function calls!
Now imagine this:
Create a Quest called "Function" with the following script:
ScriptName FunctionQuestScript short sParam1 short sParam2 short sParam3 short sResult short sResult2 float fParam1 float fParam2 float fParam3 float fResult float fResult2 ref rParam1 ref rParam2 ref rParam3 ref rResult ref rResult2
This is a generalized function framework that can be re-used for as many functions as you like.
And now make stage 10 for this quest with the following code:
; FUNCTION float Hypotenuse(float CathetusA, float CathetusB) float sqroot float n set n to ((Function.fParam1 * Function.fParam1) + (Function.fParam2 * Function.fParam2)) if (n <= 0) set Function.fResult to 1 else set sqroot to n/2 set sqroot to (sqroot + (n/sqroot))/2 set sqroot to (sqroot + (n/sqroot))/2 set sqroot to (sqroot + (n/sqroot))/2 set sqroot to (sqroot + (n/sqroot))/2 set sqroot to (sqroot + (n/sqroot))/2 set Function.fResult to (n * sqroot) endif
Okay, the function setup is complete. now to use it in a script just type:
; float Hypotenuse(float CathetusA, float CathetusB) set Function.fParam1 to SomeValue set Function.fParam2 to AnotherValue setStage Function 10 set YetAnotherValue to Function.fResult
the Function executes immediately, it is easy to use and you can put one function for each stage into this quest framework! This is especially handy when you've to work with complex mathematical functions like those HERE.
And you can easily share this functions with others since you'll only have to share the code you've put into this single stage!
(I haven't tested the functions here but they should work. Thanks to Galerion for the Square Root function.) --JustTim 18:13, 6 May 2006 (EDT)
Another cool function:
; FUNCTION float,float SinCos(float Angle) float AngleA float X float X2 float X3 float X4 float X5 float X6 float X7 float X8 float X9 short xcoeff short ycoeff set AngleA to Function.fParam1 If AngleA >= 270 Set xcoeff to 1 Set ycoeff to -1 Set AngleA to AngleA - 270 ElseIf AngleA >= 180 Set xcoeff to -1 Set ycoeff to -1 Set AngleA to AngleA - 180 ElseIf AngleA >= 90 Set xcoeff to -1 Set ycoeff to 1 Set AngleA to AngleA - 90 Else Set xcoeff to 1 Set ycoeff to 1 EndIf set X to AngleA / 57.2957792 set X2 to X*X set X3 to X2*X set X4 to X2*X2 set X5 to X4*X set X6 to X3*X3 set X7 to X5*X2 set X8 to X4*X4 set X9 to X7*X2 set AngleA to X - X3/6 + X5/120 - X7/5040 + X9/362880 - X9*X2/39916800 set Function.fResult to AngleA * ycoeff ;Sin set AngleA to 1 - X2/2 + X4/24 - X6/720 + X8/40320 - X8*X2/3628800 set Function.fResult2 to AngleA * xcoeff ;Cos
Haven't tested this too. I hope it works. Many thanks to mrflippy and Grundulum for this function! --JustTim 19:35, 6 May 2006 (EDT)
Damn, I've once again found a great limitation in scripting: It is obviously impossible to define new variables in a quest stage. It compiles, but they'll always have a value of 0. To get the above sampes to work you'll have to define all vars in the function quest script instead of the stage. i'm testing it further. --JustTim 21:55, 6 May 2006 (EDT)
Very cool: You are able to call a function (stage) from inside another function, even if both are part of the same quest! You'll just have to take care that they use diffrent veriables or the same but not at the same time. This is very handy due to the very limited size of one stage. It is also helpful to call the quest just "f" instead of "function" since you have to write the quest name for every variable you access in the script. --JustTim 22:59, 6 May 2006 (EDT)