OpenSceneGraph/src/osg/Impostor.cpp

81 lines
2.4 KiB
C++

/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2003 Robert Osfield
*
* This library is open source and may be redistributed and/or modified under
* the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
* (at your option) any later version. The full license is in LICENSE file
* included with this distribution, and on the openscenegraph.org website.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* OpenSceneGraph Public License for more details.
*/
#include <osg/Impostor>
#include <algorithm>
using namespace osg;
Impostor::Impostor()
{
_impostorThreshold = -1.0f;
}
ImpostorSprite* Impostor::findBestImpostorSprite(unsigned int contextID, const osg::Vec3& currLocalEyePoint) const
{
ImpostorSpriteList& impostorSpriteList = _impostorSpriteListBuffer[contextID];
float min_distance2 = FLT_MAX;
ImpostorSprite* impostorSprite = NULL;
for(ImpostorSpriteList::iterator itr=impostorSpriteList.begin();
itr!=impostorSpriteList.end();
++itr)
{
float distance2 = (currLocalEyePoint-(*itr)->getStoredLocalEyePoint()).length2();
if (distance2<min_distance2)
{
min_distance2 = distance2;
impostorSprite = itr->get();
}
}
return impostorSprite;
}
void Impostor::addImpostorSprite(unsigned int contextID, ImpostorSprite* is)
{
if (is && is->getParent()!=this)
{
ImpostorSpriteList& impostorSpriteList = _impostorSpriteListBuffer[contextID];
// add it to my impostor list first, so it remains referenced
// when its reference in the previous_owner is removed.
impostorSpriteList.push_back(is);
if (is->getParent())
{
Impostor* previous_owner = is->getParent();
ImpostorSpriteList& isl = previous_owner->_impostorSpriteListBuffer[contextID];
// find and erase reference to is.
for(ImpostorSpriteList::iterator itr=isl.begin();
itr!=isl.end();
++itr)
{
if ((*itr)==is)
{
isl.erase(itr);
break;
}
}
}
is->setParent(this);
}
}
bool Impostor::computeBound() const
{
return LOD::computeBound();
}