root/OpenSceneGraph/trunk/include/osgUtil/LineSegmentIntersector @ 13376

Revision 13376, 5.0 kB (checked in by robert, 4 days ago)

Added shaders to support experimental shader based displacement mapping technique osgTerrain::ShaderTerrain?.

  • Property svn:eol-style set to native
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1/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
2 *
3 * This library is open source and may be redistributed and/or modified under
4 * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
5 * (at your option) any later version.  The full license is in LICENSE file
6 * included with this distribution, and on the openscenegraph.org website.
7 *
8 * This library is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11 * OpenSceneGraph Public License for more details.
12*/
13
14#ifndef OSGUTIL_LINESEGMENTINTERSECTOR
15#define OSGUTIL_LINESEGMENTINTERSECTOR 1
16
17#include <osgUtil/IntersectionVisitor>
18
19namespace osgUtil
20{
21
22/** Concrete class for implementing line intersections with the scene graph.
23  * To be used in conjunction with IntersectionVisitor. */
24class OSGUTIL_EXPORT LineSegmentIntersector : public Intersector
25{
26    public:
27
28        /** Construct a LineSegmentIntersector the runs between the specified start and end points in MODEL coordinates. */
29        LineSegmentIntersector(const osg::Vec3d& start, const osg::Vec3d& end);
30
31        /** Construct a LineSegmentIntersector the runs between the specified start and end points in the specified coordinate frame. */
32        LineSegmentIntersector(CoordinateFrame cf, const osg::Vec3d& start, const osg::Vec3d& end);
33
34        /** Convenience constructor for supporting picking in WINDOW, or PROJECTION coordinates
35          * In WINDOW coordinates creates a start value of (x,y,0) and end value of (x,y,1).
36          * In PROJECTION coordinates (clip space cube) creates a start value of (x,y,-1) and end value of (x,y,1).
37          * In VIEW and MODEL coordinates creates a start value of (x,y,0) and end value of (x,y,1).*/
38        LineSegmentIntersector(CoordinateFrame cf, double x, double y);
39
40        struct Intersection
41        {
42            Intersection():
43                ratio(-1.0),
44                primitiveIndex(0) {}
45
46            bool operator < (const Intersection& rhs) const { return ratio < rhs.ratio; }
47
48            typedef std::vector<unsigned int>   IndexList;
49            typedef std::vector<double>         RatioList;
50
51            double                          ratio;
52            osg::NodePath                   nodePath;
53            osg::ref_ptr<osg::Drawable>     drawable;
54            osg::ref_ptr<osg::RefMatrix>    matrix;
55            osg::Vec3d                      localIntersectionPoint;
56            osg::Vec3                       localIntersectionNormal;
57            IndexList                       indexList;
58            RatioList                       ratioList;
59            unsigned int                    primitiveIndex;
60
61            const osg::Vec3d& getLocalIntersectPoint() const { return localIntersectionPoint; }
62            osg::Vec3d getWorldIntersectPoint() const { return matrix.valid() ? localIntersectionPoint * (*matrix) : localIntersectionPoint; }
63
64            const osg::Vec3& getLocalIntersectNormal() const { return localIntersectionNormal; }
65            osg::Vec3 getWorldIntersectNormal() const { return matrix.valid() ? osg::Matrix::transform3x3(osg::Matrix::inverse(*matrix),localIntersectionNormal) : localIntersectionNormal; }
66
67            /** convinience function for mapping the intersection point to any textures assigned to the objects intersected.
68             *  Returns the Texture pointer and texture coords of object hit when a texture is available on the object, returns NULL otherwise.*/
69            osg::Texture* getTextureLookUp(osg::Vec3& tc) const;
70           
71        };
72
73        typedef std::multiset<Intersection> Intersections;
74
75        inline void insertIntersection(const Intersection& intersection) { getIntersections().insert(intersection); }
76
77        inline Intersections& getIntersections() { return _parent ? _parent->_intersections : _intersections; }
78
79        inline Intersection getFirstIntersection() { Intersections& intersections = getIntersections(); return intersections.empty() ? Intersection() : *(intersections.begin()); }
80
81        inline void setStart(const osg::Vec3d& start) { _start = start; }
82        inline const osg::Vec3d& getStart() const { return _start; }
83
84        inline void setEnd(const osg::Vec3d& end) { _end = end; }
85        inline const osg::Vec3d& getEnd() const { return _end; }
86
87    public:
88
89        virtual Intersector* clone(osgUtil::IntersectionVisitor& iv);
90
91        virtual bool enter(const osg::Node& node);
92
93        virtual void leave();
94
95        virtual void intersect(osgUtil::IntersectionVisitor& iv, osg::Drawable* drawable);
96
97        virtual void reset();
98
99        virtual bool containsIntersections() { return !getIntersections().empty(); }
100
101    protected:
102
103        bool intersects(const osg::BoundingSphere& bs);
104        bool intersectAndClip(osg::Vec3d& s, osg::Vec3d& e,const osg::BoundingBox& bb);
105
106        LineSegmentIntersector* _parent;
107
108        osg::Vec3d  _start;
109        osg::Vec3d  _end;
110
111        Intersections _intersections;
112
113};
114
115}
116
117#endif
118
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