Detect if a sprite is turning left or right

Hello,

I'm working on a top down game with bullet behavior enemies. They act like aircraft, in that they turn towards the a targetX and targetY position recorded as enemy sprite instance variables. This is all working nicely, however my issue is I need to detect if the enemy is turning, or travelling in a relatively straight line.

I want to know if the enemies are turning so I can change the animation to bank left or right, or move back to being level.

Any help?

Every tick (or every x seconds), save the current angle to an instance variable (lastAngle). Make sure this is the last event/action in this group.

Compare values:

Self.Angle-Self.lastAngle > x - Play left turn animation

Self.Angle-Self.lastAngle < -x - Play right turn animation

Where x is the "dead zone" angle for going straight.

Although I feel like there is some trickery involved with going from 359 to 0 degrees for the angle, the solution evades me at the moment. Maybe someone else can help.

Ah, cool, why'd I not think of that? Will post my progress.

Kinnon

Sorry realize this isn't really going to work (was too tired when I posted). You're looking for a "signed angle" difference. There are a few ways to get this, but I'm not familiar with them.

Hi, got it working with some minor tweaks based on your initial suggestion and built a small example as proof of concept.

The event sheet is as follows:

drive.google.com/file/d/1PS6GZi07iyWO7RqTBLKLnpWftGQijTO7/view

Demo capx file can be downloaded from the link below:

drive.google.com/file/d/1TrOkX3kgPKI0EQn1QqDGzsjh9FmpuYzt/view

Thanks for the help,

Kinnon