# Rotation with movement bug

**URL:** https://forum.kirupa.com/t/rotation-with-movement-bug/80969
**Category:** flash
**Created:** [February 26, 2005, 1:48pm UTC](https://forum.kirupa.com/t/rotation-with-movement-bug/80969 "2005-02-26T13:48:39Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![Lost\_Soul](https://avatars.discourse-cdn.com/v4/letter/l/b4bc9f/32.png) [@Lost\_Soul](https://forum.kirupa.com/u/Lost_Soul)
#### Post date: [February 26, 2005, 1:48pm UTC](https://forum.kirupa.com/t/rotation-with-movement-bug/80969/1 "2005-02-26T13:48:39Z")

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[color=black][font=Arial]I’m trying to make a RTS game in flashMX 2004. I was amazed that no-one else seems to have done one and I thought it would be easy! Like I so often am, I was wrong![/font][/color]

[color=black][font=Arial] [/font][/color]

[color=black][font=Arial]The best example I can think of to explain this is; imagine trying to program a car that chases the mouse. I want to rotate the car in the direction of the mouse, but cars can’t turn on the spot, cars turn gradually in an arc as they move forward.[/font][/color]

[color=black][font=Arial]Which all works perfectly fine, unless the mouse passes by the left of the car, because then the variable myDegrees jumps from 180 to -180 or visa-versa, causing the car to rotate the long way around, until it’s pointing towards the mouse again![/font][/color]

[color=black][font=Arial] [/font][/color]

[color=black][font=Arial]There must be an easy way to sort this bug, and I’m probably just being dumb, so could someone smarter than me please give me a hand![/font][/color]  
[color=black][font=Arial][/font][/color]  
[color=black][font=Arial]…anyway, heres the code. I know I havn’t got the object moving in an arc yet, for now thats unimportant, but hopefully this gives you the idea.[/font][/color]  
[font=Times New Roman][size=3] [/size][/font]

[size=3][font=Times New Roman]onClipEvent (enterFrame) { [/font][/size]

[size=3][font=Times New Roman] // Find rotation[/font][/size]

[size=3][font=Times New Roman] myRadians = Math.atan2(\_root.\_ymouse-this.\_y, \_root.\_xmouse-this.\_x);[/font][/size]

[size=3][font=Times New Roman] myDegrees = Math.round(myRadians\*(180/Math.PI));[/font][/size]

[size=3][font=Times New Roman] // Find Movement[/font][/size]

[size=3][font=Times New Roman] \_root.yChange = Math.round(\_root.\_ymouse - this.\_y);[/font][/size]

[size=3][font=Times New Roman] \_root.xChange = Math.round(\_root.\_xmouse - this.\_x);[/font][/size]

[size=3][font=Times New Roman] \_root.yMove = Math.round(\_root.yChange/30);[/font][/size]

[size=3][font=Times New Roman] \_root.xMove = Math.round(\_root.xChange/30);[/font][/size]

[size=3][font=Times New Roman] // Apply movement[/font][/size]

[size=3][font=Times New Roman] this.\_y += \_root.yMove;[/font][/size]

[size=3][font=Times New Roman] this.\_x += \_root.xMove;[/font][/size]

[size=3][font=Times New Roman] // Apply rotation[/font][/size]

[size=3][font=Times New Roman] if (myDegrees \> this.\_rotation) this.\_rotation += 20;[/font][/size]

[size=3][font=Times New Roman] if (myDegrees \< this.\_rotation) this.\_rotation -= 20;[/font][/size]

[font=Times New Roman][size=3]}[/size][/font]

[font=Times New Roman][size=3] [/size][/font]

[font=Times New Roman][size=3]Thanks[/size][/font]