Re: [Plib-users] passing more than one value to psl scripts

[Jonathan W. <jtw...@in...>]

On Thu, 2004-11-25 at 11:31 +0100, Gerald Franz wrote:
> For our purposes it is necessary to pass each frame a 
>    larger number of variable values (e.g., 6 float values containing 
> an object's position or orientation or 16 values of a transformation 
> matrix) to the scripts. I succeeded in accessing these data 
> individually by writing access functions that return just one specific 
> ordinate, but I could not find a mechanism to pass a complete array. 
> It seems pretty cumbersome and like a lot of overhead to need 6 or 
> even 16 function calls for such an initialization.

I've been pondering the same question, and the best idea I have been
able to come up with is to use an int value as a handle with each unique
value representing an sgVec or sgMat, then writing wrapper functions for
all the lowlevel sg functions. so for example if I wanted to add two
vectors I could use:

in c++

sgVec3 position;
sgVec3 offset;
sgVec3 result;

sgAddVec3(&result, &position, &offset);

or in psl

int position_handle = pslGetVec3Handle("position");
int offset_handle = pslGetVec3Handle("offset");
int result_handle = pslNewVec3("result");

pslSgAddVec3(result_handle,position_handle, offset_handle);

There would be some added overhead in matching hashes, but hopefully
most of it could be simplified to only happen once per script.  I
haven't tried this out yet, so I have no idea if it would work.
Any suggestions?

-Jonathan