Sorry your browser is not supported!

You are using an outdated browser that does not support modern web technologies, in order to use this site please update to a new browser.

Browsers supported include Chrome, FireFox, Safari, Opera, Internet Explorer 10+ or Microsoft Edge.

DarkBASIC Professional Discussion / Reversing a vector...

Author
Message
iaretony
23
Years of Service
User Offline
Joined: 6th Jun 2003
Location:
Posted: 18th Jul 2003 02:47
Link
How do you get a vector2 to point in the opposite direction (IE, + || - 180 degrees)?

Tony
Back to top
Profile PM
Shadow Robert
23
Years of Service
User Offline
Joined: 22nd Sep 2002
Location: Hertfordshire, England
Posted: 18th Jul 2003 03:06
Link
well you could always do



that way positive or negative it'll just swap the -/+
but i thought that was pretty obvious math

Back to top
Profile PM Email Website
iaretony
23
Years of Service
User Offline
Joined: 6th Jun 2003
Location:
Posted: 18th Jul 2003 03:56
Link
I was hoping for something slicker... Like:

scale vector2 fw_trace_vector, fw_trace_vector, -1

Will that work? At first I thought so, but now I think it will only
work if the x and y components are positive...

Tony

Back to top
Profile PM
Shadow Robert
23
Years of Service
User Offline
Joined: 22nd Sep 2002
Location: Hertfordshire, England
Posted: 18th Jul 2003 05:39
Link
i dunno why you'd think that somehow doing it with the scaler would help... i mean all of the 3dmath commands can be recreated (and work just as fast) if made by hand.
atleast this way its 100% accurate

Back to top
Profile PM Email Website
keeblerElf
23
Years of Service
User Offline
Joined: 11th Jun 2003
Location: United States
Posted: 18th Jul 2003 07:52
Link
Yeah all you need to do to rotate a vector 180 degrees is to multiple the vector by the scalar -1. if you want to rotate a vector by a different degree than say you have a know vector A and and unknown vector B and you want to rotate it C degrees that you could solve (AoB)/|A+B|=C where AoB is the dot product of vectors A and B

Back to top
Profile PM
Shadow Robert
23
Years of Service
User Offline
Joined: 22nd Sep 2002
Location: Hertfordshire, England
Posted: 18th Jul 2003 07:56
Link
but what is the point?
you end up spending like 20steps to do the exact same as the code i've provided much slower... i think less should be though about on how "neat" or "looks" of the code is and more on the actual features.

Back to top
Profile PM Email Website
Back to top

Login to post a reply

Server time is: 2026-07-21 12:50:15
Your offset time is: 2026-07-21 12:50:15