[JASS] GetCameraTargetPositionX/Y

[Starquizer]

I want to make a camera shake option so that when a player scrolls the camera to a certain location the camera will start shaking but I don't know how the function GetCameraTargetPositionXGetCameraTargetPositionY works for multi-player. So far I made something like this:

    private function cameraShake takes real x,real y returns nothing
        local real camx = GetCameraTargetPositionX()
        local real camy = GetCameraTargetPositionY()
        local real dx = x - camx
        local real dy = y - camy
        local real dist = SquareRoot( dx*dx + dy*dy )
        if dist <= 500. then
            // Start Shaking the camera
        endif
    endfunction

 

[Maker]

Use GetLocalPlayer, like this for example:

    private function cameraShake takes real x,real y returns nothing
        local real dx
        local real dy
        local integer i = 0

        loop
            if GetLocalPlayer() == Player(i) then
                set dx = x - GetCameraTargetPositionX()
                set dy = y - GetCameraTargetPositionY()
                if SquareRoot( dx*dx + dy*dy ) <= 500. then
                    // Start Shaking the camera
                endif
             endif
             exitwhen i == 11
             set i = i + 1
        endloop
    endfunction

 

[Starquizer]

If you don't mind asking, what does GetLocalPlayer() do ?

 

[Maker]

It returns the player which is running the code.

 

[WaterKnight]

You do not need it if you do not want to filter the player out. GetCameraTargetPositionX/Y returns different values for different players. So you are fine as long as you do not do something gameplay-relevant within the if-block.

Also, distances can be compared by comparing their squares, so dx*dx + dy*dy <= 500.*500. is fine, saves the relatively slow SquareRoot function call.

 

[Starquizer]

...
Also, distances can be compared by comparing their squares, so dx*dx + dy*dy <= 500.*500. is fine, saves the relatively slow SquareRoot function call.

I like that .

 

[Troll-Brain]

I'm not sure SquareRoot is that slow in jass, i mean since jass is slowly interpreted, that could be irrevelant, or even faster than one longer expression without SquareRoot.

(No i don't care to test it)

 

[Starquizer]

...
(No i don't care to test it)

How things like that can be tested ?

 

[Maker]

How things like that can be tested ?

You create a script that does lots of sqrt operations in a short time, then compare the FPS drop or time taken to execute the script to another with no sqrt operation.