321 lines
11 KiB
Plaintext
321 lines
11 KiB
Plaintext
//C++ header - Open Scene Graph - Copyright (C) 1998-2001 Robert Osfield
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//Distributed under the terms of the GNU Library General Public License (LGPL)
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//as published by the Free Software Foundation.
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#ifndef OSG_POLYTOPE
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#define OSG_POLYTOPE 1
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#include <osg/Plane>
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#include <osg/fast_back_stack>
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namespace osg {
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/** A Polytope class for representing convex clipping volumes made up.
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* When adding planes, their normals should point inwards (into the volume) */
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class SG_EXPORT Polytope
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{
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public:
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typedef unsigned int ClippingMask;
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typedef std::vector<Plane> PlaneList;
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typedef fast_back_stack<ClippingMask> MaskStack;
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inline Polytope() {setupMask();}
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inline Polytope(const Polytope& cv) :
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_maskStack(cv._maskStack),
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_resultMask(cv._resultMask),
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_planeList(cv._planeList) {}
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inline Polytope(const PlaneList& pl) : _planeList(pl) {setupMask();}
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inline ~Polytope() {}
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inline void clear() { _planeList.clear(); setupMask(); }
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inline Polytope& operator = (const Polytope& cv)
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{
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if (&cv==this) return *this;
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_maskStack = cv._maskStack;
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_resultMask = cv._resultMask;
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_planeList = cv._planeList;
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return *this;
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}
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/** Create a Polytope with is cube, centered at 0,0,0, with sides of 2 units.*/
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void setToUnitFrustum(bool withNear=true, bool withFar=true)
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{
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_planeList.erase(_planeList.begin(),_planeList.end());
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_planeList.push_back(Plane(1.0f,0.0f,0.0f,1.0f)); // left plane.
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_planeList.push_back(Plane(-1.0f,0.0f,0.0f,1.0f)); // right plane.
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_planeList.push_back(Plane(0.0f,1.0f,0.0f,1.0f)); // bottom plane.
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_planeList.push_back(Plane(0.0f,-1.0f,0.0f,1.0f)); // top plane.
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if (withNear) _planeList.push_back(Plane(0.0f,0.0f,-1.0f,1.0f)); // near plane
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if (withFar) _planeList.push_back(Plane(0.0f,0.0f,1.0f,1.0f)); // far plane
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setupMask();
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}
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inline void set(const PlaneList& pl) { _planeList = pl; setupMask(); }
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inline void add(const osg::Plane& pl) { _planeList.push_back(pl); setupMask(); }
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/** flip/reverse the orientation of all the planes.*/
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inline void flip()
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{
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for(PlaneList::iterator itr=_planeList.begin();
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itr!=_planeList.end();
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++itr)
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{
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itr->flip();
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}
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}
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inline PlaneList& getPlaneList() { return _planeList; }
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inline const PlaneList& getPlaneList() const { return _planeList; }
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inline void setupMask()
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{
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_resultMask = 0;
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for(unsigned int i=0;i<_planeList.size();++i)
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{
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_resultMask = (_resultMask<<1) | 1;
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}
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_maskStack.back() = _resultMask;
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}
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inline ClippingMask& getCurrentMask() { return _maskStack.back(); }
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inline ClippingMask getCurrentMask() const { return _maskStack.back(); }
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inline void setResultMask(ClippingMask mask) { _resultMask=mask; }
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inline ClippingMask getResultMask() const { return _resultMask; }
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MaskStack& getMaskStack() { return _maskStack; }
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const MaskStack& getMaskStack() const { return _maskStack; }
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inline void pushCurrentMask()
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{
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_maskStack.push_back(_resultMask);
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}
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inline void popCurrentMask()
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{
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_maskStack.pop_back();
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}
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/** Check whether a vertex is contained with clipping set.*/
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inline const bool contains(const osg::Vec3& v) const
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{
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if (!_maskStack.back()) return true;
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unsigned int selector_mask = 0x1;
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for(PlaneList::const_iterator itr=_planeList.begin();
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itr!=_planeList.end();
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++itr)
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{
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if ((_maskStack.back()&selector_mask) && (itr->distance(v)<0.0f)) return false;
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selector_mask <<= 1;
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}
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return true;
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}
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/** Check whether any part of vertex list is contained with clipping set.*/
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inline const bool contains(const std::vector<Vec3>& vertices)
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{
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if (!_maskStack.back()) return true;
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_resultMask = _maskStack.back();
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ClippingMask selector_mask = 0x1;
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for(PlaneList::const_iterator itr=_planeList.begin();
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itr!=_planeList.end();
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++itr)
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{
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if (_resultMask&selector_mask)
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{
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int res=itr->intersect(vertices);
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if (res<0) return false; // outside clipping set.
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else if (res>0) _resultMask ^= selector_mask; // subsequent checks against this plane not required.
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}
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selector_mask <<= 1;
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}
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return true;
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}
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/** Check whether any part of a bounding sphere is contained within clipping set.
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Using a mask to determine which planes should be used for the check, and
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modifying the mask to turn off planes which wouldn't contribute to clipping
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of any internal objects. This feature is used in osgUtil::CullVisitor
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to prevent redundant plane checking.*/
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inline const bool contains(const osg::BoundingSphere& bs)
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{
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if (!_maskStack.back()) return true;
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_resultMask = _maskStack.back();
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ClippingMask selector_mask = 0x1;
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for(PlaneList::const_iterator itr=_planeList.begin();
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itr!=_planeList.end();
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++itr)
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{
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if (_resultMask&selector_mask)
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{
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int res=itr->intersect(bs);
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if (res<0) return false; // outside clipping set.
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else if (res>0) _resultMask ^= selector_mask; // subsequent checks against this plane not required.
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}
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selector_mask <<= 1;
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}
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return true;
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}
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/** Check whether any part of a bounding box is contained within clipping set.
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Using a mask to determine which planes should be used for the check, and
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modifying the mask to turn off planes which wouldn't contribute to clipping
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of any internal objects. This feature is used in osgUtil::CullVisitor
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to prevent redundant plane checking.*/
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inline const bool contains(const osg::BoundingBox& bb)
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{
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if (!_maskStack.back()) return true;
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_resultMask = _maskStack.back();
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ClippingMask selector_mask = 0x1;
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for(PlaneList::const_iterator itr=_planeList.begin();
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itr!=_planeList.end();
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++itr)
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{
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if (_resultMask&selector_mask)
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{
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int res=itr->intersect(bb);
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if (res<0) return false; // outside clipping set.
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else if (res>0) _resultMask ^= selector_mask; // subsequent checks against this plane not required.
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}
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selector_mask <<= 1;
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}
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return true;
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}
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/** Check whether all of vertex list is contained with clipping set.*/
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inline const bool containsAllOf(const std::vector<Vec3>& vertices)
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{
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if (!_maskStack.back()) return false;
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_resultMask = _maskStack.back();
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ClippingMask selector_mask = 0x1;
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for(PlaneList::const_iterator itr=_planeList.begin();
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itr!=_planeList.end();
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++itr)
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{
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if (_resultMask&selector_mask)
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{
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int res=itr->intersect(vertices);
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if (res<1) return false; // intersects, or is below plane.
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_resultMask ^= selector_mask; // subsequent checks against this plane not required.
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}
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selector_mask <<= 1;
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}
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return true;
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}
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/** Check whether the entire bounding sphere is contained within clipping set.*/
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inline const bool containsAllOf(const osg::BoundingSphere& bs)
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{
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if (!_maskStack.back()) return false;
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_resultMask = _maskStack.back();
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ClippingMask selector_mask = 0x1;
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for(PlaneList::const_iterator itr=_planeList.begin();
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itr!=_planeList.end();
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++itr)
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{
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if (_resultMask&selector_mask)
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{
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int res=itr->intersect(bs);
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if (res<1) return false; // intersects, or is below plane.
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_resultMask ^= selector_mask; // subsequent checks against this plane not required.
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}
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selector_mask <<= 1;
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}
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return true;
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}
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/** Check whether the entire bounding box is contained within clipping set.*/
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inline const bool containsAllOf(const osg::BoundingBox& bb)
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{
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if (!_maskStack.back()) return false;
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_resultMask = _maskStack.back();
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ClippingMask selector_mask = 0x1;
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for(PlaneList::const_iterator itr=_planeList.begin();
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itr!=_planeList.end();
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++itr)
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{
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if (_resultMask&selector_mask)
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{
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int res=itr->intersect(bb);
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if (res<1) return false; // intersects, or is below plane.
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_resultMask ^= selector_mask; // subsequent checks against this plane not required.
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}
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selector_mask <<= 1;
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}
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return true;
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}
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/** Transform the clipping set by matrix. Note, this operations carries out
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* the calculation of the inverse of the matrix since to transforms
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* planes must be multiplied my the inverse transposed. This
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* make this operation expensive. If the inverse has been already
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* calculated elsewhere then use transformProvidingInverse() instead.
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* See http://www.worldserver.com/turk/computergraphics/NormalTransformations.pdf*/
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inline void transform(const osg::Matrix& matrix)
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{
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osg::Matrix inverse;
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inverse.invert(matrix);
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transformProvidingInverse(inverse);
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}
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/** Transform the clipping set by provide a pre inverted matrix.
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* see transform for details. */
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inline void transformProvidingInverse(const osg::Matrix& matrix)
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{
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if (!_maskStack.back()) return;
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_resultMask = _maskStack.back();
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ClippingMask selector_mask = 0x1;
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for(PlaneList::iterator itr=_planeList.begin();
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itr!=_planeList.end();
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++itr)
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{
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if (_resultMask&selector_mask)
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{
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itr->transformProvidingInverse(matrix);
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selector_mask <<= 1;
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}
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}
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}
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protected:
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MaskStack _maskStack;
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ClippingMask _resultMask;
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PlaneList _planeList;
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};
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} // end of namespace
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#endif
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