How do I count rotations?

How do I count rotations of a sprite?

(I want to combine rotation count with time.

The sprite is moved with the cursor buttons and uses a physics behavior)

The idea behind this question is: for example in Excitebike you want to tell the player: "good! You did 2 rotations in 2 seconds!"

<img src="http://upload.wikimedia.org/wikipedia/en/thumb/9/95/Excitebike.png/250px-Excitebike.png" border="0" />

Use a variable and add the angle difference of the sprite to it every tick.

The "AngleDiff()" expression is not satisfactory since it doesn't give the direction of the angle difference (CW or CCW). So I used this method:

http://blog.lexique-du-net.com/index.php?post/Calculate-the-real-difference-between-two-angles-keeping-the-sign

capx:

http://dl.dropbox.com/u/5426011/examples10/total_rotation.capx

Thanks, I will try this!

On my way to work...looks promising will let you know many thanks!

Hey R0J0hound...it took me all of 15 minutes to integrate this into my game and get it to register backwards and forwards 360's(negative and positive).

It was easy to reset the total rotation to zero ready to measure the next flip etc. I can see how i could hold the count to also register 720's etc, but i think i'll just have a fading graphic (bullet behavior)at the completion of each 360 to replace the test text display in the pic.

I never would have thought to use instance variables. Truthfully i also doubt my brain could have come up with the comparison thing either.. You saved me days of head scratching. I salute your most excellent brain and your community spirit. many thanks for your help!

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