function IsUnitBehindUnit takes unit u2, unit u1 returns boolean
local real face = GetUnitFacing(u1)
local real rangle = bj_RADTODEG*Atan2(GetUnitY(u2)-GetUnitY(u1),GetUnitX(u2)-GetUnitX(u1))
return not (RAbsBJ(face-rangle) < 90 or RAbsBJ(face-rangle-360) < 90)
endfunction
function IsPointInCone takes real x1, real y1, real x2, real y2, real f, real a returns boolean
return Cos(Atan2(y2-y1,x2-x1)-f) > Cos(a)
endfunction
//x1,y1: coordinates of the cone origin
//x2,y2: coordinates tested against the cone
//f: orientation of the cone in radians
//a: halved opening angle of the cone in radians (90° cone: bj_DEGTORAD*45)
Untitled Trigger 001
Events
Conditions
Actions
Set TempUnit[0] = "A unit"
Set TempUnit[1] = "A unit"
Set TempLocation[0] = (Position of TempUnit[0])
Set TempLocation[1] = (Position of TempUnit[1])
Set TempReal[0] = (Facing of TempUnit[0])
Set TempReal[1] = (Angle from TempLocation[0] to TempLocation[1])
Custom script: call RemoveLocation(udg_TempLocation[0])
Custom script: call RemoveLocation(udg_TempLocation[1])
-------- - --------
Set TempReal[2] = (Max(TempReal[0], TempReal[1]))
Set TempReal[3] = (Min(TempReal[0], TempReal[1]))
Set TempReal[4] = (TempReal[2] - TempReal[3])
Set TempReal[5] = (360.00 - (TempReal[2] + TempReal[3]))
Set TempReal[6] = (Min(TempReal[4], TempReal[5]))
-------- - --------
If (All Conditions are True) then do (Then Actions) else do (Else Actions)
If - Conditions
TempReal[6] Greater than or equal to 90.00
Then - Actions
-------- TempUnit[1] is behind TempUnit[0] --------
Else - Actions
-------- TempUnit[1] is not behind TempUnit[0] --------
No but the output from cosine is the same at -350, 10, 370 etc. As you know from your high-school trigonometry class already.
There is. The one we are telling you about...
Angle Test Example Init
Events
Map initialization
Conditions
Actions
Set ANGBOU_ATE_30 = (Cos((180.00 - 30.00)))
Angle Test Example
Events
Unit - A unit Is attacked
Conditions
Actions
-------- setup register variables --------
Set RegUnitA = (Attacking unit)
Set RegUnitB = (Attacked unit)
Set RegLocA = (Position of RegUnitA)
Set RegLocB = (Position of RegUnitB)
-------- perform test --------
If (All Conditions are True) then do (Then Actions) else do (Else Actions)
If - Conditions
(Cos(((Angle from RegLocB to RegLocA) - (Facing of RegUnitB)))) Less than or equal to ANGBOU_ATE_30
Then - Actions
Unit - Cause RegUnitA to damage RegUnitB, dealing 100.00 damage of attack type Spells and damage type Normal
Else - Actions
-------- clean up --------
Custom script: call RemoveLocation(udg_RegLocA)
Custom script: call RemoveLocation(udg_RegLocB)
No but the output from cosine is the same at -350, 10, 370 etc. As you know from your high-school trigonometry class already.
The best part is that for all real inputs cosine is defined as that repeating output. As such angles that wrap around to >360 or <0 do not matter as you get the correct output all the time.
By applying an inequality (testing for a range) to the output of cosine you then test a range of input angles. The value used for the test is easily produced by a cosine of the maximum deviant angle you want to allow. The symmetry and repeating nature of cosine handles it all for you.
There is. The one we are telling you about...
I created you a little demo map showing the approach I am referring to. In the demo map attacking a unit from directly behind +/- 30 degrees will deal 100 spell damage to the attacked unit. You will be able to try this for yourself by using the footman provided in the demo map which deal 0 damage to attack (and kill) the Blood Mages directly north of you.
This trigger is used for initialization.
And this does the actual testing for dealing damage.
The two lines of custom script are for leak prevention and not required for the actual test (but are recommended because leaks can cause maps to perform badly).
Cosine is symmetrical around every 0 and 180 degrees. As the graph shows. Try for yourself and see.
Seriously, did you even bother trying it even once before throwing your hands in the air, screaming "OMG IT'S JASS; RUN!!"?
.Learning JASS helped me become a qualified Computer Scientist.
Once you know one programming language, you can pretty much learn them all without much effort. For example if I was to be shown JASS now without any prior knowledge about it I could probably pick it up in an hour or two just from seeing the main script files.
There's no need to understand it. It's two simple functions that have input parameters and give you an output boolean that tells you if the unit is behind or not. You don't have to understand how a calculator works internally in order to calculate 2+2. This is similar.
What, so you even know how to use Custom Script? Then what exactly is the problem? Just call the function and be done with it. It works exactly the same as removing a location via Custom script.
