C++ LLVector3::magVecSquared方法代码示例

void LLViewerObjectList::shiftObjects(const LLVector3 &offset)
{
	// This is called when we shift our origin when we cross region boundaries...
	// We need to update many object caches, I'll document this more as I dig through the code
	// cleaning things out...

	if (gNoRender || 0 == offset.magVecSquared())
	{
		return;
	}

	LLViewerObject *objectp;
	S32 i;
	for (i = 0; i < mObjects.count(); i++)
	{
		objectp = getObject(i);
		// There could be dead objects on the object list, so don't update stuff if the object is dead.
		if (objectp)
		{
			objectp->updatePositionCaches();

			if (objectp->mDrawable.notNull() && !objectp->mDrawable->isDead())
			{
				gPipeline.markShift(objectp->mDrawable);
			}
		}
	}

	gPipeline.shiftObjects(offset);
	gWorldPointer->mPartSim.shift(offset);
}

void LLViewerObjectList::shiftObjects(const LLVector3 &offset)
{
	// This is called when we shift our origin when we cross region boundaries...
	// We need to update many object caches, I'll document this more as I dig through the code
	// cleaning things out...

	if (gNoRender || 0 == offset.magVecSquared())
	{
		return;
	}

	LLViewerObject *objectp;
	for (vobj_list_t::iterator iter = mObjects.begin(); iter != mObjects.end(); ++iter)
	{
		objectp = *iter;
		// There could be dead objects on the object list, so don't update stuff if the object is dead.
		if (objectp && !objectp->isDead())
		{
			objectp->updatePositionCaches();

			if (objectp->mDrawable.notNull() && !objectp->mDrawable->isDead())
			{
				gPipeline.markShift(objectp->mDrawable);
			}
		}
	}

	gPipeline.shiftObjects(offset);
	LLWorld::getInstance()->shiftRegions(offset);
}

// Saves space by using the fact that our quaternions are normalized
void LLQuaternion::unpackFromVector3( const LLVector3& vec )
{
	mQ[VX] = vec.mV[VX];
	mQ[VY] = vec.mV[VY];
	mQ[VZ] = vec.mV[VZ];
	F32 t = 1.f - vec.magVecSquared();
	if( t > 0 )
	{
		mQ[VW] = sqrt( t );
	}
	else
	{
		// Need this to avoid trying to find the square root of a negative number due
		// to floating point error.
		mQ[VW] = 0;
	}
}

//.........这里部分代码省略.........
				if ( are_parallel(poleVec, agVec, 0.001f) )
				{
					// the solutions is also singular
					return;
				}
				else
				{
					abcNorm = poleVec % agVec;
				}
			}
			else
			{
				abcNorm = poleVec % abVec;
			}
		}
		else
		{
			abcNorm = abVec % bcVec;
		}
	}
	else
	{
		abcNorm = mBAxis * mJointB->getWorldRotation();
	}

	//-------------------------------------------------------------------------
	// compute rotation of B
	//-------------------------------------------------------------------------
	// angle between A->B and B->C
	F32 abbcAng = angle_between(abVec, bcVec);

	// vector orthogonal to A->B and B->C
	LLVector3 abbcOrthoVec = abVec % bcVec;
	if (abbcOrthoVec.magVecSquared() < 0.001f)
	{
		abbcOrthoVec = poleVec % abVec;
		abacCompOrthoVec = poleVec;
	}
	abbcOrthoVec.normVec();

	F32 agLenSq = agLen * agLen;

	// angle arm for extension
	F32 cosTheta =	(agLenSq - abLen*abLen - bcLen*bcLen) / (2.0f * abLen * bcLen);
	if (cosTheta > 1.0f)
		cosTheta = 1.0f;
	else if (cosTheta < -1.0f)
		cosTheta = -1.0f;

	F32 theta = acos(cosTheta);

	LLQuaternion bRot(theta - abbcAng, abbcOrthoVec);

//	llinfos << "abbcAng      : " << abbcAng << llendl;
//	llinfos << "abbcOrthoVec : " << abbcOrthoVec << llendl;
//	llinfos << "agLenSq      : " << agLenSq << llendl;
//	llinfos << "cosTheta     : " << cosTheta << llendl;
//	llinfos << "theta        : " << theta << llendl;
//	llinfos << "bRot         : " << bRot << llendl;
//	llinfos << "theta abbcAng theta-abbcAng: " << theta*180.0/F_PI << " " << abbcAng*180.0f/F_PI << " " << (theta - abbcAng)*180.0f/F_PI << llendl;

	//-------------------------------------------------------------------------
	// compute rotation that rotates new A->C to A->G
	//-------------------------------------------------------------------------
	// rotate B->C by bRot
	bcVec = bcVec * bRot;

BOOL LLVOPartGroup::updateGeometry(LLDrawable *drawable)
{
	LLFastTimer ftm(LLFastTimer::FTM_UPDATE_PARTICLES);

 	LLVector3 at;
	LLVector3 position_agent;
	LLVector3 camera_agent = gCamera->getOrigin();
	
	S32 num_parts = mViewerPartGroupp->getCount();
	LLFace *facep;
	LLSpatialGroup* group = drawable->getSpatialGroup();
	if (!group && num_parts)
	{
		drawable->movePartition();
		group = drawable->getSpatialGroup();
	}

	if (!num_parts)
	{
		if (group && drawable->getNumFaces())
		{
			group->dirtyGeom();
		}
		drawable->setNumFaces(0, NULL, getTEImage(0));
		LLPipeline::sCompiles++;
		return TRUE;
	}

 	if (!(gPipeline.hasRenderType(LLPipeline::RENDER_TYPE_PARTICLES)))
	{
		return TRUE;
	}

	if (num_parts > drawable->getNumFaces())
	{
		drawable->setNumFacesFast(num_parts+num_parts/4, NULL, getTEImage(0));
	}

	F32 tot_area = 0;

	F32 max_area = LLViewerPartSim::getMaxPartCount() * MAX_PARTICLE_AREA_SCALE; 
	F32 pixel_meter_ratio = gCamera->getPixelMeterRatio();
	pixel_meter_ratio *= pixel_meter_ratio;

	S32 count=0;
	S32 i;
	mDepth = 0.f;

	for (i = 0; i < num_parts; i++)
	{
		const LLViewerPart &part = *((LLViewerPart*) mViewerPartGroupp->mParticles[i]);

		LLVector3 part_pos_agent(part.mPosAgent);
		at = part_pos_agent - camera_agent;

		F32 camera_dist_squared = at.magVecSquared();
		F32 inv_camera_dist_squared;
		if (camera_dist_squared > 1.f)
			inv_camera_dist_squared = 1.f / camera_dist_squared;
		else
			inv_camera_dist_squared = 1.f;
		F32 area = part.mScale.mV[0] * part.mScale.mV[1] * inv_camera_dist_squared;
		tot_area += area;
 		
		if (tot_area > max_area)
		{
			break;
		}
	
		count++;

		facep = drawable->getFace(i);
		if (!facep)
		{
			llwarns << "No face found for index " << i << "!" << llendl;
			continue;
		}

		facep->setTEOffset(i);
		const F32 NEAR_PART_DIST_SQ = 5.f*5.f;  // Only discard particles > 5 m from the camera
		const F32 MIN_PART_AREA = .005f*.005f;  // only less than 5 mm x 5 mm at 1 m from camera
		
		if (camera_dist_squared > NEAR_PART_DIST_SQ && area < MIN_PART_AREA)
		{
			facep->setSize(0, 0);
			continue;
		}

		facep->setSize(4, 6);
		
		facep->setViewerObject(this);

		if (part.mFlags & LLPartData::LL_PART_EMISSIVE_MASK)
		{
			facep->setState(LLFace::FULLBRIGHT);
		}
		else
		{
			facep->clearState(LLFace::FULLBRIGHT);
		}
//.........这里部分代码省略.........