How to check if a point is inside a 2D cone

[Reventhous]

I've been wondering, how to check if a point is inside a 2D cone.
My idea is,

1. Check if the point is within radius by using group.
2. Define angleStart and angleEnd and check if the point is within it.

Everything goes fine until I tested in with 270-90 degree (not a cone actually, a hemi-sphere). The system tell me that the point is outside.

Any solution?

 

[pOke]

Can you post your code?

I was doing something similar recently, and found out that Atan2 is defined between -180 and 180 rather than 0 and 360.
So I was getting some incorrect results when I went to a particular angle.

You may be experiencing a similar situation where a function is limited to values you're not expecting.

 

[Pyrogasm]

Obviously if distance < R, then check (Cos((AngleToCenterOfCone - AngleToPoint))) Greater than or equal to (Cos(HALF_ARC_LENGTH)).
This will technically be a sector, not a cone, but it really doesn't matter that much. As seen used here.

 

[Wietlol]

I apply this check in my GroupAddUnitsInCone() function:

            set difference = DenormalizeAngleDeg(AngleBetweenCoordinatesDeg(x, y, GetUnitX(FoG), GetUnitY(FoG)) - direction)
            if difference > -size and difference < size then
                call GroupAddUnit(whichGroup, FoG)
            endif

(This is applied after a GroupEnumUnitsInRange() so the range check is already applied.)
What it basically does is it takes the angle from the origin point to the point that you want to check.
Then substract the direction of your cone.
Then make sure that the angle is in -180 to 180 format.
(Aka, if your angle is above 180, then substract 360.)
Then check if the result is closer to 0 than the maximum angle that is allowed (from the center to the edge, so 90-270 would have a 90 degrees maximum angle).)

 

[Dr Super Good]

For cone tests either use cosine or use a modulo 360 angel.