/** Utility function that calculates filling factor */
const float CalculateFillingFactor(const FSphere& ASphere, const float AFillingFactor, const FSphere& BSphere, const float BFillingFactor)
{
const float OverlapVolume = CalculateOverlap( ASphere, AFillingFactor, BSphere, BFillingFactor);
FSphere UnionSphere = ASphere + BSphere;
// it shouldn't be zero or it should be checked outside
ensure(UnionSphere.W != 0.f);
// http://deim.urv.cat/~rivi/pub/3d/icra04b.pdf
// cost is calculated based on r^3 / filling factor
// since it subtract by AFillingFactor * 1/2 overlap volume + BfillingFactor * 1/2 overlap volume
return FMath::Max(0.0f, (AFillingFactor * ASphere.GetVolume() + BFillingFactor * BSphere.GetVolume() - OverlapVolume) / UnionSphere.GetVolume());
}
void ApplyNoteExpulsion (FloatNote * psNote, NotesPersist * psNotesData) {
float fXForce, fYForce;
FloatNote * psNoteCount;
GSList * psNoteListPos;
float fCoverage;
float fXDirection, fYDirection, fLength;
float fFade;
fXForce = 0.0f;
fYForce = 0.0f;
psNoteListPos = psNotesData->psNoteList;
while (psNoteListPos) {
psNoteCount = (FloatNote *)psNoteListPos->data;
if (psNoteCount != psNote) {
// Calculate fade
fFade = (1.0f - ((psNoteCount->vsAnchor.fZ - psNotesData->fFocusFar + NOTE_FOCUSSHIFT) * NOTE_FOCUSFADE));
if ((psNoteCount->szText->len > 0) && (fFade > 0.0f) && (fFade < 50.0f)) {
// Calculate coverage
fCoverage = CalculateOverlap (psNote->vsPos.fX, psNote->vsSize.fX, psNoteCount->vsPos.fX, psNoteCount->vsSize.fX) * CalculateOverlap (psNote->vsPos.fY, psNote->vsSize.fY, psNoteCount->vsPos.fY, psNoteCount->vsSize.fY);
if (fCoverage > 0.0f) {
fXDirection = ((psNote->vsPos.fX + (psNote->vsSize.fX / 2.0f)) - (psNoteCount->vsPos.fX + (psNoteCount->vsSize.fX / 2.0f)));
fYDirection = ((psNote->vsPos.fY + (psNote->vsSize.fY / 2.0f)) - (psNoteCount->vsPos.fY + (psNoteCount->vsSize.fY / 2.0f)));
fLength = sqrt ((fXDirection * fXDirection) + (fYDirection * fYDirection));
fXForce += psNotesData->fExpulsion * (40.0f + fCoverage) * fXDirection * fFade / fLength;
fYForce += psNotesData->fExpulsion * (40.0f + fCoverage) * fYDirection * fFade / fLength;
}
}
}
psNoteListPos = psNoteListPos->next;
}
psNote->vsVel.fX += 0.01f * fXForce;
psNote->vsVel.fY += 0.01f * fYForce;
}
