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From Peter Hrenka, "Due to popular demand I would like to submit this

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enhanced version of PolytopeIntersector.


New features of PolytopeIntersector :

* Dimension mask: The user may specify the dimensions of the
   primitives to be tested. Checking polytope-triangle and
   polytope-quad intersections is rather slow so this can
   be turned off.
* Reference plane: The resulting intersections are sorted
   by the distance to this plane.

New memebers of PolytopeIntersector::Intersection :

* distance: Distance of localIntersectionPoint to the reference plane
* maxDistance: Maximum distance of all intersectionPoints to the
   reference plane.
* intersectionPoints: The points intersecting the planes of the polytope
   or points completely inside the polytope.
* localIntersectionPoint: arithmetic mean of all intersection points
* primitiveIndex: Index of the primitive that intersected


I added some more output to the example osgkeyboardmouse."
This commit is contained in:
Robert Osfield
2007-12-08 16:37:05 +00:00
parent 195ed8ba26
commit 65bef96a6e
3 changed files with 477 additions and 282 deletions
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56
include/osgUtil/PolytopeIntersector
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@@ -24,14 +24,21 @@ namespace osgUtil
class OSGUTIL_EXPORT PolytopeIntersector : public Intersector
{
public:
/** Construct a PolytopeIntersector using speified polytope in MODEL coordinates.*/
/// dimension enum to specify primitive types to check.
enum {
DimZero = (1<<0), ///< check for points
DimOne = (1<<1), ///< check for lines
DimTwo = (1<<2), ///< check for triangles, quad
AllDims = (DimZero | DimOne | DimTwo)
};
/** Construct a PolytopeIntersector using specified polytope in MODEL coordinates.*/
PolytopeIntersector(const osg::Polytope& polytope);
/** Construct a PolytopeIntersector using speified polytope in specified coordinate frame.*/
/** Construct a PolytopeIntersector using specified polytope in specified coordinate frame.*/
PolytopeIntersector(CoordinateFrame cf, const osg::Polytope& polytope);
/** Convinience constructor for supporting picking in WINDOW, or PROJECTION coorindates
/** Convenience constructor for supporting picking in WINDOW, or PROJECTION coordinates
* In WINDOW coordinates (clip space cube) creates a five sided polytope box that has a front face at 0.0 and sides around box xMin, yMin, xMax, yMax.
* In PROJECTION coordinates (clip space cube) creates a five sided polytope box that has a front face at -1 and sides around box xMin, yMin, xMax, yMax.
* In VIEW and MODEL coordinates (clip space cube) creates a five sided polytope box that has a front face at 0.0 and sides around box xMin, yMin, xMax, yMax.*/
@@ -40,16 +47,29 @@ class OSGUTIL_EXPORT PolytopeIntersector : public Intersector
struct Intersection
{
Intersection() {}
bool operator < (const Intersection& rhs) const
{
if (distance < rhs.distance) return true;
if (rhs.distance < distance) return false;
if (primitiveIndex < rhs.primitiveIndex) return true;
if (rhs.primitiveIndex < primitiveIndex) return false;
if (nodePath < rhs.nodePath) return true;
if (rhs.nodePath < nodePath ) return false;
return (drawable < rhs.drawable);
}
enum { MaxNumIntesectionPoints=6 };
double distance; ///< distance from reference plane
double maxDistance; ///< maximum distance of intersection points from reference plane
osg::NodePath nodePath;
osg::ref_ptr<osg::Drawable> drawable;
osg::ref_ptr<osg::RefMatrix> matrix;
osg::Vec3 localIntersectionPoint; ///< center of all intersection points
unsigned int numIntersectionPoints;
osg::Vec3 intersectionPoints[MaxNumIntesectionPoints];
unsigned int primitiveIndex; ///< primitive index
};
typedef std::set<Intersection> Intersections;
@@ -60,6 +80,23 @@ class OSGUTIL_EXPORT PolytopeIntersector : public Intersector
inline Intersection getFirstIntersection() { Intersections& intersections = getIntersections(); return intersections.empty() ? Intersection() : *(intersections.begin()); }
inline unsigned int getDimensionMask() const { return _dimensionMask; }
/** set the dimension mask.
* As polytope-triangle and polytope-quad intersections are expensive to compute
* it is possible to turn them off by calling setDimensionMask( DimZero | DimOne )
*/
inline void setDimensionMask(unsigned int dimensionMask) { _dimensionMask = dimensionMask; }
inline const osg::Plane& getReferencePlane() const { return _referencePlane; }
/** set the plane used to sort the intersections.
* The intersections are sorted by the distance of the localIntersectionPoint
* and the reference plane. The default for the reference plane is the
* last plane of the polytope.
*/
inline void setReferencePlane(const osg::Plane& plane) { _referencePlane = plane; }
public:
virtual Intersector* clone(osgUtil::IntersectionVisitor& iv);
@@ -79,7 +116,10 @@ class OSGUTIL_EXPORT PolytopeIntersector : public Intersector
PolytopeIntersector* _parent;
osg::Polytope _polytope;
unsigned int _dimensionMask; ///< mask which dimensions should be checked
osg::Plane _referencePlane; ///< plane to use for sorting intersections
Intersections _intersections;
};