[JASS] Need help with some jass

[wolfman]

I am working on a completely customizable projectile system in JASS. I am having some trouble with one part though. I want to make it so the projectile is able to home in on a nearby enemy unit. The problem isnt finding the enemy unit, but actually making the missile go to the unit. I want to make something that does not use global arrays. Also the missiles always travel in their facing direction, so i must make the missile slowly face its target.

Heres the basic idea of what i have:

Loc1 = position of target
Loc2 = position of missile
Angle1 = Facing of missile
Angle2 = Where i want the missile to face
call SetUnitFacing(GetEnumUnit(), Angle2)
...........................^ enum unit is the missile

I pretty much need a formula where i can use these points and angles to determine which way the missile should face. This really has me stumped, i have been trying to make it work for a while now and im not getting too far, so any help would be appreciated.
I will give you rep if you help me

 

[GhostWolf]

You need the missiles' speed since you need to figure out how much movements it will take to get to the target.
Once you figure that, you rotate the missile by angle/movements where angle is the angle difference between the missile and the target.

You will need to do this very often of course since the unit can move.

 

[wolfman]

The speed isnt the problem... I just want to figure out a way to make the missile face its target over time by setting its facing degrees closer and closer to the target. I DONT want to do something like SetUnitFacingToFaceLocTimed because that makes it turn too fast and it isnt as customizable. The only trouble i am having is how to find the angle.

 

[Element of Water]

You shouldn't make it go towards its facing direction. You should use vectors. It's easy to calculate stuff like that with vectors, plus it's faster (not as much trigonometry). Then you can just make it face the vector's direction.

From what I've gathered, you're not using vJass. No-one would use your system if it's in normal Jass, and it'd be really laggy. I suggest you learn vJass and recode it if it's not already in vJass.

 

[YourNameHere]

You shouldn't make it go towards its facing direction. You should use vectors. It's easy to calculate stuff like that with vectors, plus it's faster (not as much trigonometry). Then you can just make it face the vector's direction.

From what I've gathered, you're not using vJass. No-one would use your system if it's in normal Jass, and it'd be really laggy. I suggest you learn vJass and recode it if it's not already in vJass.

amen.

 

[ACDS2]

You shouldn't make it go towards its facing direction. You should use vectors. It's easy to calculate stuff like that with vectors, plus it's faster (not as much trigonometry). Then you can just make it face the vector's direction.

From what I've gathered, you're not using vJass. No-one would use your system if it's in normal Jass, and it'd be really laggy. I suggest you learn vJass and recode it if it's not already in vJass.

I don't see how vJass can be faster than normal Jass, since they are the same script language and vJass is probably slower with object-orientated features from custom vJass compiler.

I have many things in normal jass and i am pretty happy with using them in different maps.

Getting the facing to one point from another is easy, you just need 3 steps:

1.Make a new point(target pointY - origin pointY, target pointX - origin pointX)
2.Use arc tangent(there should be a jass native to do that) on new point = facing from projectile to target position(might need to be converted degree's depends the type jass native returns)
3.Use facing to turn projectile

 

[Element of Water]

vJass isn't faster or slower than normal Jass, but its features allow you to write faster code more easily. Making a struct containing all your data and accessing it in a loop with a global timer, for example, is much faster than having to allocate a different timer for each individual unit affected by the spell and attaching data to them via gamecache (or the new hashtables).

 

[wolfman]

Well for this system there is only one timer
It is also all in one trigger with about 190 lines (alot of it is conditions though)
It does lag, but only when there are about 20 projectiles at one time, which most likely wouldnt happen in game (at least i dont think so >.<)

I dont really understand what you were saying ACDS2, but i actually got it to almost work and this is what i have so far:

...

    set a = GetUnitFacing(GetEnumUnit())
    set anglea = a
    set b = AngleBetweenPoints(loc4, loc3)
    set c = b + 180
    if (not( b > 180 and b < 360)) then
        if a > c then
            set angle = anglea - homing
        endif
        if a < c then
            set angle = anglea + homing
        endif
    endif
    if (b > 180 and b < 360) then
        set c = c - 360
        if a > c then
            set angle = anglea - homing
        endif
        if a < c then
            set angle = anglea + homing
        endif
        set c = c + 360
    endif
    call SetUnitFacing(GetEnumUnit(), angle)

loc4 is the position of the target and loc3 is the position of the missile
The only problem is that sometimes the missile turns the wrong way.

...a

.......b
.....==>

'a' is the target and 'b' is the missile
it is facing the direction of the arrow, so it should turn up, but instead it turns down and makes 3/4 of a circle to face the target.
This is pretty much the only situation where this happens, otherwise it takes the shortest route.
pretend the dots are not there in the 'picture' i attempted to make

 

[GhostWolf]

It shouldn't lag at just 20 entities. Never.

As to what ACDS2 said, that's basically vectors.

 

[Element of Water]

HindyHAT made a full blown physics engine that only lags at around 200. A simple projectile system is completely fail if it lags at 20.

 

[wolfman]

Yeah i know... im not finished with it yet.

I actually did get it to work, i just have to figure out how to make it more efficient, if anyone has any ideas or can rewrite this for me so its more efficient i would really appreciate it
(this is only the part that sets the missiles facing direction)

turn

set loc3 = GetUnitLoc(GetEnumUnit())
    set loc4 = GetUnitLoc(udg_Closest)
    set a = GetUnitFacing(GetEnumUnit())
    set b = AngleBetweenPoints(loc4, loc3)
    if b < 180 then
        set c = b + 180
    endif
    if b > 180 then
        set c = b - 180
    endif
    if a - c > 180 then
        set angle = a + homing
    endif
    if a - c < 180 then
        if a - c > 0 then
            set angle = a - homing
        else
            set angle = a + homing
        endif
    endif
    if a > 0 then
        if a < 90 then
            if c > a + 180 then
                if c < 360 then
                    set angle = a - homing
                endif
            endif
        endif
    endif
    call SetUnitFacing(GetEnumUnit(), angle)

 

[Element of Water]

Omfg. Long, crappy, unnecessary code. Seriously, no-one in their right mind will even think about using this system...

 

[wolfman]

I know >.<
Im working on fixing it, its my first system give me a break lol

 

[Element of Water]

Learn vJass FFS. No-one uses normal Jass anymore...

 

[GhostWolf]

Seriously.

Nicer code > The 10 miliseconds you lose because of the nicer code.

 

[wolfman]

Yeah i know i have to learn vjass, but i think i have to learn jass first. Im not really experienced with jass, but im learning, and in order to learn you must make mistakes and fix them. You cant expect me to make it perfectly efficient the first time...im just asking for help, im not asking you to tell me over and over again that my code isnt efficient, it really doesnt help at all. I am very aware that it isnt efficient, but that is what im working on. So if you wanna help me out then help me, if you dont then you dont have to continue telling me how bad my code is