Creative AWE32 - Page 109

SB AWE32 Developer's Information Pack PART V 3D Positional Audio API •• 108
Copyright  Creative Technology Ltd., 1994-1996 Version 3.00
/* | a[3] a[4] a[5] | */
/* | a[6] a[7] a[8] | */
c3daReceiver rx; /* handle to c3da core receiver */
/* need to be "created" using */
/* c3daCreateReceiver */
} Receiver;
/*
* as an example, allocate some global emitters and one receiver
*/
Receiver thisRx;
Emitter Em[NUMBER_OF_EMITTERS];
/*
* sample "world" setEmitterPosition routine
*/
void
setEmitterPosition( Emitter* pEm, int x, int y, int z )
{
int new_x, new_y, new_z;
/*
* save the world coordinates
*/
pEm->x = x;
pEm->y = y;
pEm->z = z;
/*
* rotate this emitter so that it is relative to the fixed
* receiver in the c3da core
*/
new_x = thisRx.a[0]*x + thisRx.a[1]*y + thisRx.a[2]*z;
new_y = thisRx.a[3]*x + thisRx.a[4]*y + thisRx.a[5]*z;
new_z = thisRx.a[6]*x + thisRx.a[7]*y + thisRx.a[8]*z;
/*
* now tell the c3da core about the new position
*/
c3daSetEmitterPosition ( &(pEm->em), new_x, new_y, new_z );
}
/*
* sample "world" setReceiverOrientation routine
*
* Arguments:
* yaw - rotation around the z-axis (-180 to 180 degrees)
* pitch - rotation around the y-axis (-180 to 180 degrees)
* roll - rotation around the x-axis (-180 to 180 degrees)
*
* Notes:
* o order of rotations - roll, pitch, yaw
* o Instead of actually changing the orientation of the receiver,
* we equivalently move all the emitters around the fixed receiver
* in the c3da core. The rotation matrix used to move the emitters
* is simply the transpose of the "composite" rotation matrix defined
* by yaw, pitch, roll and the order of rotations.
*/
void
setReceiverOrientation( int yaw, int pitch, int roll )
{
float yaw_f;
float pitch_f;
float roll_f;
/*
* convert yaw, pitch, and roll to radians