void SFXSource::_updateVolume( const MatrixF& listener )
{
const F32 volume = mVolume * mModulativeVolume;
if ( !mIs3D )
{
mDistToListener = 0.0f;
mAttenuatedVolume = volume;
return;
}
Point3F pos, lpos;
mTransform.getColumn( 3, &pos );
listener.getColumn( 3, &lpos );
mDistToListener = ( pos - lpos ).len();
mAttenuatedVolume = SFXDistanceAttenuation(
SFX->getDistanceModel(),
mMinDistance,
mMaxDistance,
mDistToListener,
volume,
SFX->getRolloffFactor() );
}
void SFXEmitter::_renderCone( F32 radialIncrements, F32 sweepIncrements,
F32 pointDistance,
F32 startAngle, F32 stopAngle,
F32 startVolume, F32 stopVolume,
const ColorI& color )
{
if( startAngle == stopAngle )
return;
const F32 startAngleRadians = mDegToRad( startAngle );
const F32 stopAngleRadians = mDegToRad( stopAngle );
const F32 radialIncrementsRadians = mDegToRad( radialIncrements );
// Unit quaternions representing the start and end angle so we
// can interpolate between the two without flipping.
QuatF rotateZStart( EulerF( 0.f, 0.f, startAngleRadians / 2.f ) );
QuatF rotateZEnd( EulerF( 0.f, 0.f, stopAngleRadians / 2.f ) );
// Do an angular sweep on one side of our XY disc. Since we do a full 360 radial sweep
// around Y for each angle, we only need to sweep over one side.
const F32 increment = 1.f / ( ( ( startAngle / 2.f ) - ( stopAngle / 2.f ) ) / sweepIncrements );
for( F32 t = 0.f; t < 1.0f; t += increment )
{
// Quaternion to rotate point into place on XY disc.
QuatF rotateZ;
rotateZ.interpolate( rotateZStart, rotateZEnd, t );
// Quaternion to rotate one position around Y axis. Used for radial sweep.
QuatF rotateYOne( EulerF( 0.f, radialIncrementsRadians, 0.f ) );
// Do a radial sweep each step along the distance axis. For each step, volume is
// the same for any point on the sweep circle.
for( F32 y = pointDistance; y <= mDescription.mMaxDistance; y += pointDistance )
{
ColorI c = color;
// Compute volume at current point. First off, find the interpolated volume
// in the cone. Only for the outer cone will this actually result in
// interpolation. For the remaining angles, the cone volume is constant.
F32 volume = mLerp( startVolume, stopVolume, t );
if( volume == 0.f )
c.alpha = 0;
else
{
// Apply distance attenuation.
F32 attenuatedVolume = SFXDistanceAttenuation(
SFX->getDistanceModel(),
mDescription.mMinDistance,
mDescription.mMaxDistance,
y,
volume,
SFX->getRolloffFactor() ); //RDTODO
// Fade alpha according to how much volume we
// have left at the current point.
c.alpha = F32( c.alpha ) * ( attenuatedVolume / 1.f );
}
PrimBuild::color( c );
// Create points by doing a full 360 degree radial sweep around Y.
Point3F p( 0.f, y, 0.f );
rotateZ.mulP( p, &p );
for( F32 radialAngle = 0.f; radialAngle < 360.f; radialAngle += radialIncrements )
{
PrimBuild::vertex3f( p.x, p.y, p.z );
rotateYOne.mulP( p, &p );
}
}
}
}
