# Help with some Math (Probably easy)

#### dudeim

##### New Member
Hey,

as I'm not that much of a math genius, well not much of a math anything I need some help with a calculation.

What I want to do is I'm gonna fire an arrow towards an angle that the player can just click.
So the player clicks to his precise left (for example) the arrow flies that way and then I want to know when the arrow is like 800 range further or 1000 range further etc.. so i can destroy it.

Can anyone help me with this?
I know I didn't explain it too good if you need extra description just ask

Thanks!

Well, you can always attach the starting XY coordinates to the projectile. Then when you move that projectile, check the distance between its current and starting positions:

JASS:
``````
function DistanceBetweenXY takes real x1, real y1, real x2, real y2 returns real
return SquareRoot((x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1))
endfunction

private method periodic takes nothing returns nothing
local real x=&lt;New X&gt;
local real y=&lt;New Y&gt;
call SetUnitPosition(this.dummy,x,y)
if DistanceBetweenXY (x,y,this.strX,this.strY)&lt;=800. then
call this.stopPeriodic()
endif
endmethod``````

That is pretty smart gonna try it! thanks

Better idea is to increase the distance moved on every interval, and compare that to the maximum range.

Well as I'm not calculating the distance itself every interval (using a system for it) I think it's easier to go with luorax's way.

General chit-chat
Help Users
• No one is chatting at the moment.
• The Helper:
https://www.thehelper.net/pages/news/ is a link to the old news portal - i will integrate it into the interface somewhere when i figure it out
• Ghan:
Need to try something
• Ghan:
Hopefully this won't cause problems.
• Ghan:
Hmm
• Ghan:
I have converted the Headline News forum to an Article type forum. It will now show the top 20 threads with more detail of each thread.
• Ghan:
See how we like that.
• The Helper:
I do not see a way to go past the 1st page of posts on the forum though
• The Helper:
It is OK though for the main page to open up on the forum in the view it was before. As long as the portal has its own URL so it can be viewed that way I do want to try it as a regular forum view for a while
• Ghan:
Yeah I'm not sure what the deal is with the pagination.
• Ghan:
It SHOULD be there so I think it might just be an artifact of having an older style.
• Ghan:
I switched it to a "Standard" article forum. This will show the thread list like normal, but the threads themselves will have the first post set up above the rest of the "comments"
• The Helper:
I don't really get that article forum but I think it is because I have never really seen it used on a multi post thread
• Ghan:
RpNation makes more use of it right now as an example: https://www.rpnation.com/news/
• The Helper:
• The Helper:
What do you think Tom?
• tom_mai78101:
I will have to get used to this.
• tom_mai78101:
The latest news feed looks good
• The Helper:
I would like to see it again like Ghan had it the first time with pagination though - without the pagination that view will not work but with pagination it just might...
• The Helper:
This drink recipe I have had more than a few times back in the day! Mind Eraser https://www.thehelper.net/threads/cocktail-mind-eraser.194720/
• The Helper:
Happy Thursday!
• Ghan:
I'm not so sure, there's still a lot of Thursday left for it to become unhappy.
+3
• The Helper:
still a few hours
• The Helper:
Its Friday!!!!
+1
• Ghan:
Thursday 7/10 would Thursday again
+3