simgear/scene/bvh/BVHLineSegmentVisitor.cxx

   1 // Copyright (C) 2008 - 2009  Mathias Froehlich - Mathias.Froehlich@web.de
   2 //
   3 // This library is free software; you can redistribute it and/or
   4 // modify it under the terms of the GNU Library General Public
   5 // License as published by the Free Software Foundation; either
   6 // version 2 of the License, or (at your option) any later version.
   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 GNU
  11 // Library General Public License for more details.
  12 //
  13 // You should have received a copy of the GNU General Public License
  14 // along with this program; if not, write to the Free Software
  15 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  16 //
  17
  18 #include <simgear/math/SGMath.hxx>
  19 #include "BVHLineSegmentVisitor.hxx"
  20
  21 #include <simgear/math/SGGeometry.hxx>
  22
  23 #include "BVHVisitor.hxx"
  24
  25 #include "BVHNode.hxx"
  26 #include "BVHGroup.hxx"
  27 #include "BVHTransform.hxx"
  28 #include "BVHMotionTransform.hxx"
  29 #include "BVHLineGeometry.hxx"
  30 #include "BVHStaticGeometry.hxx"
  31
  32 #include "BVHStaticData.hxx"
  33
  34 #include "BVHStaticNode.hxx"
  35 #include "BVHStaticTriangle.hxx"
  36 #include "BVHStaticBinary.hxx"
  37
  38 namespace simgear {
  39
  40 void
  41 BVHLineSegmentVisitor::apply(BVHGroup& group)
  42 {
  43     if (!intersects(_lineSegment, group.getBoundingSphere()))
  44         return;
  45     group.traverse(*this);
  46 }
  47
  48 void
  49 BVHLineSegmentVisitor::apply(BVHTransform& transform)
  50 {
  51     if (!intersects(_lineSegment, transform.getBoundingSphere()))
  52         return;
  53
  54     bool haveHit = _haveHit;
  55     _haveHit = false;
  56
  57     // Push the line segment
  58     SGLineSegmentd lineSegment = getLineSegment();
  59     _lineSegment = transform.lineSegmentToLocal(lineSegment);
  60
  61     transform.traverse(*this);
  62
  63     if (_haveHit) {
  64         _linearVelocity = transform.vecToWorld(_linearVelocity);
  65         _angularVelocity = transform.vecToWorld(_angularVelocity);
  66         SGVec3d point(transform.ptToWorld(_lineSegment.getEnd()));
  67         _lineSegment.set(lineSegment.getStart(), point);
  68         _normal = transform.vecToWorld(_normal);
  69     } else {
  70         _lineSegment = lineSegment;
  71         _haveHit = haveHit;
  72     }
  73 }
  74
  75 void
  76 BVHLineSegmentVisitor::apply(BVHMotionTransform& transform)
  77 {
  78     if (!intersects(_lineSegment, transform.getBoundingSphere()))
  79         return;
  80
  81     bool haveHit = _haveHit;
  82     _haveHit = false;
  83
  84     // Push the line segment
  85     SGLineSegmentd lineSegment = getLineSegment();
  86     SGMatrixd toLocal = transform.getToLocalTransform(_time);
  87     _lineSegment = lineSegment.transform(toLocal);
  88
  89     transform.traverse(*this);
  90
  91     if (_haveHit) {
  92         SGMatrixd toWorld = transform.getToWorldTransform(_time);
  93         SGVec3d localStart = _lineSegment.getStart();
  94         _linearVelocity += transform.getLinearVelocityAt(localStart);
  95         _angularVelocity += transform.getAngularVelocity();
  96         _linearVelocity = toWorld.xformVec(_linearVelocity);
  97         _angularVelocity = toWorld.xformVec(_angularVelocity);
  98         SGVec3d localEnd = _lineSegment.getEnd();
  99         _lineSegment.set(lineSegment.getStart(), toWorld.xformPt(localEnd));
 100         _normal = toWorld.xformVec(_normal);
 101         if (!_id)
 102             _id = transform.getId();
 103     } else {
 104         _lineSegment = lineSegment;
 105         _haveHit = haveHit;
 106     }
 107 }
 108
 109 void
 110 BVHLineSegmentVisitor::apply(BVHLineGeometry&)
 111 {
 112 }
 113
 114 void
 115 BVHLineSegmentVisitor::apply(BVHStaticGeometry& node)
 116 {
 117     if (!intersects(_lineSegment, node.getBoundingSphere()))
 118         return;
 119     node.traverse(*this);
 120 }
 121
 122 void
 123 BVHLineSegmentVisitor::apply(const BVHStaticBinary& node,
 124                              const BVHStaticData& data)
 125 {
 126     if (!intersects(SGLineSegmentf(_lineSegment), node.getBoundingBox()))
 127         return;
 128
 129     // The first box to enter is the one the startpoint is in.
 130     // this increases the probability, that on exit of that box we do not
 131     // even need to walk the other one, since the line segment is
 132     // then already short enough to not intersect the other one anymore.
 133     node.traverse(*this, data, _lineSegment.getStart());
 134 }
 135
 136 void
 137 BVHLineSegmentVisitor::apply(const BVHStaticTriangle& triangle,
 138                              const BVHStaticData& data)
 139 {
 140     SGTrianglef tri = triangle.getTriangle(data);
 141     SGVec3f point;
 142     if (!intersects(point, tri, SGLineSegmentf(_lineSegment), 1e-4f))
 143         return;
 144     setLineSegmentEnd(SGVec3d(point));
 145     _normal = SGVec3d(tri.getNormal());
 146     _linearVelocity = SGVec3d::zeros();
 147     _angularVelocity = SGVec3d::zeros();
 148     _material = data.getMaterial(triangle.getMaterialIndex());
 149     _id = 0;
 150     _haveHit = true;
 151 }
 152
 153
 154 }