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why degrees?

Started by DemOSh Oct 30, 2002 at 3:17 AM 4 replies 750+ views

Original Post

Oct 30, 2002 at 3:17 AM

I was just thinkin, is there any particular reason why opengl uses degrees instead of radians (glRotate)? Im sure it wasnt an arbitrary decision to go with degrees rather than radians. Is it just a matter of convenience? 90.0f is easier to write and remember than (3.141592654/2)? Since the standard library functions use radians, and radians have some intresting properties that degrees lack, I think it would have made more sense to use them instead...

Nypyren

Oct 30, 2002 at 3:31 AM

They what?! OMG! OpenGL uses Degrees??? LOL!

That makes it a serious pain if you deal with standard atan results!

57.2958 becomes your FRIEND.

"MMM... Pi."

Zorodius

Oct 30, 2002 at 9:42 AM

Because radians are for communists.

What I really want to know is, why is the top left corner''s texture coordinate at (0.0, 1.0)?? That''s ABSURD! Computer graphics have been using 0,0 as the top left corner for ages, and yet OpenGL thinks it can just change things around and make higher numbers represent higher coordinates?? MADNESS, I TELL YOU!

Deyja

Oct 30, 2002 at 9:53 AM

Why not?

Brother Bob

Oct 30, 2002 at 10:04 AM

OpenGL was not really designed (in the first place) to be a gaming API. It was designed for the industry market, like proffesional modelling, drawing and visulaization.

If you draw a 2D coordinate system on a paper (as when you draw a graph or so), I bet you place the origin in the lower left corner and not he upper left corner, making the positive X-axis point right, and the positive Y-axis point up. So if OpenGL was indended for this kind of applications, why not make it that way?

Not that I have done much mechanical drawings in CAD programs, but in the introduction course I had, we measured the angles in degrees, not radians. So again, if OpenGL was designed for this, why not make it that way?

zedzeek

Oct 30, 2002 at 2:59 PM

yes maths use (0,0) as the lower left (publishing + text use (0,0) as the upper left.
want to hear crazy
2d (0,0) is upper left thus x== right y==down
ok lets exapand that to 3d thus x==right y==UP z==in/out (depending your handness)
of course this is unlogical, (using (0,0) as the top left)

the 2d axises orientations should be retained when u move into 3d (u just add another one to them)

http://uk.geocities.com/sloppyturds/kea/kea.html
http://uk.geocities.com/sloppyturds/gotterdammerung.html

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