# Flash Coordinate system and target tracking

**URL:** https://forum.kirupa.com/t/flash-coordinate-system-and-target-tracking/226830
**Category:** flash
**Created:** [May 24, 2007, 12:43pm UTC](https://forum.kirupa.com/t/flash-coordinate-system-and-target-tracking/226830 "2007-05-24T12:43:29Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![Cedwyn](https://avatars.discourse-cdn.com/v4/letter/c/eb9ed0/32.png) [@Cedwyn](https://forum.kirupa.com/u/Cedwyn)
#### Post date: [May 24, 2007, 12:43pm UTC](https://forum.kirupa.com/t/flash-coordinate-system-and-target-tracking/226830/1 "2007-05-24T12:43:29Z")

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Hey all,

Does anyone have a good resource on understanding the flash coordinate system - it is beyond conventional.

I am trying to design a system where a missile (or other object) tracks the mouse around the screen. However the missile only has a max rotation, so if the mouse is behind it, it slowly turns in an arc until it can lock-on to the mouse’s position.

However, when trying to determine the x/y position, you cannot use x=cos(ang) or y=sin(ang). It seems opposite, such as x=sin(ang), y=cos(ang) - contrary to what it should be. Furthermore, the quandrant system is odd, the bottom half is 0-180, and the top half is -1 to -180…

So I am beyond confused. I am either hoping their is a way to change the coordinate system (like in many other programming languages) or a resource on programming physical movement using the current system.

Thank you,  
Elf

Edit - I did some more research and discovered that rotation uses degrees and everything else is radians. I have fixed my errors now, I didn’t realise that not everything was degrees 🙂