BOOL LLVOSurfacePatch::lineSegmentIntersect(const LLVector4a& start, const LLVector4a& end, S32 face, BOOL pick_transparent, S32 *face_hitp, LLVector4a* intersection,LLVector2* tex_coord, LLVector4a* normal, LLVector4a* tangent) { if (!lineSegmentBoundingBox(start, end)) { return FALSE; } LLVector4a da; da.setSub(end, start); LLVector3 delta(da.getF32ptr()); LLVector3 pdelta = delta; pdelta.mV[2] = 0; F32 plength = pdelta.length(); F32 tdelta = 1.f/plength; LLVector3 v_start(start.getF32ptr()); LLVector3 origin = v_start - mRegionp->getOriginAgent(); if (mRegionp->getLandHeightRegion(origin) > origin.mV[2]) { //origin is under ground, treat as no intersection return FALSE; } //step one meter at a time until intersection point found //VECTORIZE THIS const LLVector4a* exta = mDrawable->getSpatialExtents(); LLVector3 ext[2]; ext[0].set(exta[0].getF32ptr()); ext[1].set(exta[1].getF32ptr()); F32 rad = (delta*tdelta).magVecSquared(); F32 t = 0.f; while ( t <= 1.f) { LLVector3 sample = origin + delta*t; if (AABBSphereIntersectR2(ext[0], ext[1], sample+mRegionp->getOriginAgent(), rad)) { F32 height = mRegionp->getLandHeightRegion(sample); if (height > sample.mV[2]) { //ray went below ground, positive intersection //quick and dirty binary search to get impact point tdelta = -tdelta*0.5f; F32 err_dist = 0.001f; F32 dist = fabsf(sample.mV[2] - height); while (dist > err_dist && tdelta*tdelta > 0.0f) { t += tdelta; sample = origin+delta*t; height = mRegionp->getLandHeightRegion(sample); if ((tdelta < 0 && height < sample.mV[2]) || (height > sample.mV[2] && tdelta > 0)) { //jumped over intersection point, go back tdelta = -tdelta; } tdelta *= 0.5f; dist = fabsf(sample.mV[2] - height); } if (intersection) { F32 height = mRegionp->getLandHeightRegion(sample); if (fabsf(sample.mV[2]-height) < delta.length()*tdelta) { sample.mV[2] = mRegionp->getLandHeightRegion(sample); } intersection->load3((sample + mRegionp->getOriginAgent()).mV); } if (normal) { normal->load3((mRegionp->getLand().resolveNormalGlobal(mRegionp->getPosGlobalFromRegion(sample))).mV); } return TRUE; } } t += tdelta; if (t > 1 && t < 1.f+tdelta*0.99f) { //make sure end point is checked (saves vertical lines coming up negative) t = 1.f; } } return FALSE; }
S32 AABBSphereIntersect(const LLVector4a& min, const LLVector4a& max, const LLVector3 &origin, const F32 &rad) { return AABBSphereIntersectR2(min, max, origin, rad*rad); }