Re: [Plib-users] API Documentation and Camera Rotation....

[Steve B. <sjb...@ai...>]

SkyFlash wrote:
> Alright, i am experimenting with PLIB right now, but I am kinda lost
> without docu or help....

There is SSG documentation on the web site - and several example
programs.

> I wanna do a few things and how no clue how...
> 
> - Create a floor, which is basicly flat and textured, if possible not
> from a 3D model but just from code.

Look at (for example) src/ssgAux/ssgaShapes.cxx - look at 'ssgaCube::regenerate()'
on about line 184.  That builds a cube without loading it from disk.

> - Have a camera which is locked in an isometric position, looking down
> at a certain angle onto a defined point.

There are at least four ways:

ssgSetCamera ( sgMat4 mat ) ;       -- Give it a matrix describing it's
                                        position and orientation.
ssgSetCamera ( sgCoord *coord ) ;   -- Give it an sgCoord (which contains
                                        X,Y,Z and H,P,R)

ssgSetCameraLookAt ( sgVec3 eyepoint, sgVec3 center ) ; -- Give it a position
                                        and a point in space to look towards.

ssgSetCameraLookAt ( sgVec3 eyepoint, sgVec3 center, sgVec3 up ) ; -- Ditto
                                        and also specify the "up" direction.

> - Have that camera rotate on keypress around that defined point to keep
> the angle on it.

Read the keypress in whatever way suits your application, figure out
the new position - call 'ssgSetCameraLookAt' each time it moves to
reposition it and/or it's "look at" point.

> Now I know SOME 3D math, but I have no clue how to set the coordinates
> for the camera, how to set the angle for the camera, how to make it look
> towards some point in space. Which functions are used for that and whats
> the argument list? Or better, where can I look up that information and
> also for the rest of the API?

It's on the web site.  Go to http://plib.sf.net/ssg

> I pretty much want the setup like in Diablo II, if that helps to
> visualize what I want, just that the camera can be rotated around the
> center point. (where the map is centered on)

I don't know Diablo.  I only write computer games - I don't have time
to play them too!  :-)

> For the floor, I just need some floor so I can see when I move the
> camera and of course later for the game as a real floor. :P

Yep.

If you want, you can download either 'Tuxkart' or 'TuxAQFH' and
'steal' one of the 'levelXXX.ac' files to load initially.  It's
a lot more interesting than just a flat plane - and you can load
it with just a single 'ssgLoad ( filename )' call.

---------------------------- Steve Baker -------------------------
HomeEmail: <sjb...@ai...>    WorkEmail: <sj...@li...>
HomePage : http://www.sjbaker.org
Projects : http://plib.sf.net    http://tuxaqfh.sf.net
            http://tuxkart.sf.net http://prettypoly.sf.net