simgear/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 #ifdef HAVE_CONFIG_H
  19 #  include <simgear_config.h>
  20 #endif
  21
  22 #include "BVHLineSegmentVisitor.hxx"
  23
  24 #include <simgear/math/SGGeometry.hxx>
  25
  26 #include "BVHVisitor.hxx"
  27
  28 #include "BVHNode.hxx"
  29 #include "BVHGroup.hxx"
  30 #include "BVHTransform.hxx"
  31 #include "BVHMotionTransform.hxx"
  32 #include "BVHLineGeometry.hxx"
  33 #include "BVHStaticGeometry.hxx"
  34
  35 #include "BVHStaticData.hxx"
  36
  37 #include "BVHStaticNode.hxx"
  38 #include "BVHStaticTriangle.hxx"
  39 #include "BVHStaticBinary.hxx"
  40
  41 namespace simgear {
  42
  43 void
  44 BVHLineSegmentVisitor::apply(BVHGroup& group)
  45 {
  46     if (!intersects(_lineSegment, group.getBoundingSphere()))
  47         return;
  48     group.traverse(*this);
  49 }
  50
  51 void
  52 BVHLineSegmentVisitor::apply(BVHTransform& transform)
  53 {
  54     if (!intersects(_lineSegment, transform.getBoundingSphere()))
  55         return;
  56
  57     bool haveHit = _haveHit;
  58     _haveHit = false;
  59
  60     // Push the line segment
  61     SGLineSegmentd lineSegment = getLineSegment();
  62     _lineSegment = transform.lineSegmentToLocal(lineSegment);
  63
  64     transform.traverse(*this);
  65
  66     if (_haveHit) {
  67         _linearVelocity = transform.vecToWorld(_linearVelocity);
  68         _angularVelocity = transform.vecToWorld(_angularVelocity);
  69         SGVec3d point(transform.ptToWorld(_lineSegment.getEnd()));
  70         _lineSegment.set(lineSegment.getStart(), point);
  71         _normal = transform.vecToWorld(_normal);
  72     } else {
  73         _lineSegment = lineSegment;
  74         _haveHit = haveHit;
  75     }
  76 }
  77
  78 void
  79 BVHLineSegmentVisitor::apply(BVHMotionTransform& transform)
  80 {
  81     if (!intersects(_lineSegment, transform.getBoundingSphere()))
  82         return;
  83
  84     bool haveHit = _haveHit;
  85     _haveHit = false;
  86
  87     // Push the line segment
  88     SGLineSegmentd lineSegment = getLineSegment();
  89     SGMatrixd toLocal = transform.getToLocalTransform(_time);
  90     _lineSegment = lineSegment.transform(toLocal);
  91
  92     transform.traverse(*this);
  93
  94     if (_haveHit) {
  95         SGMatrixd toWorld = transform.getToWorldTransform(_time);
  96         SGVec3d localStart = _lineSegment.getStart();
  97         _linearVelocity += transform.getLinearVelocityAt(localStart);
  98         _angularVelocity += transform.getAngularVelocity();
  99         _linearVelocity = toWorld.xformVec(_linearVelocity);
 100         _angularVelocity = toWorld.xformVec(_angularVelocity);
 101         SGVec3d localEnd = _lineSegment.getEnd();
 102         _lineSegment.set(lineSegment.getStart(), toWorld.xformPt(localEnd));
 103         _normal = toWorld.xformVec(_normal);
 104         if (!_id)
 105             _id = transform.getId();
 106     } else {
 107         _lineSegment = lineSegment;
 108         _haveHit = haveHit;
 109     }
 110 }
 111
 112 void
 113 BVHLineSegmentVisitor::apply(BVHLineGeometry&)
 114 {
 115 }
 116
 117 void
 118 BVHLineSegmentVisitor::apply(BVHStaticGeometry& node)
 119 {
 120     if (!intersects(_lineSegment, node.getBoundingSphere()))
 121         return;
 122     node.traverse(*this);
 123 }
 124
 125 void
 126 BVHLineSegmentVisitor::apply(const BVHStaticBinary& node,
 127                              const BVHStaticData& data)
 128 {
 129     if (!intersects(SGLineSegmentf(_lineSegment), node.getBoundingBox()))
 130         return;
 131
 132     // The first box to enter is the one the startpoint is in.
 133     // this increases the probability, that on exit of that box we do not
 134     // even need to walk the other one, since the line segment is
 135     // then already short enough to not intersect the other one anymore.
 136     node.traverse(*this, data, _lineSegment.getStart());
 137 }
 138
 139 void
 140 BVHLineSegmentVisitor::apply(const BVHStaticTriangle& triangle,
 141                              const BVHStaticData& data)
 142 {
 143     SGTrianglef tri = triangle.getTriangle(data);
 144     SGVec3f point;
 145     if (!intersects(point, tri, SGLineSegmentf(_lineSegment), 1e-4f))
 146         return;
 147     setLineSegmentEnd(SGVec3d(point));
 148     _normal = SGVec3d(tri.getNormal());
 149     _linearVelocity = SGVec3d::zeros();
 150     _angularVelocity = SGVec3d::zeros();
 151     _material = data.getMaterial(triangle.getMaterialIndex());
 152     _id = 0;
 153     _haveHit = true;
 154 }
 155
 156
 157 }