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 #ifdef HAVE_CONFIG_H
  19 #  include <simgear_config.h>
  20 #endif
  21
  22 #include <simgear/math/SGMath.hxx>
  23 #include "BVHLineSegmentVisitor.hxx"
  24
  25 #include <simgear/math/SGGeometry.hxx>
  26
  27 #include "BVHVisitor.hxx"
  28
  29 #include "BVHNode.hxx"
  30 #include "BVHGroup.hxx"
  31 #include "BVHTransform.hxx"
  32 #include "BVHMotionTransform.hxx"
  33 #include "BVHLineGeometry.hxx"
  34 #include "BVHStaticGeometry.hxx"
  35
  36 #include "BVHStaticData.hxx"
  37
  38 #include "BVHStaticNode.hxx"
  39 #include "BVHStaticTriangle.hxx"
  40 #include "BVHStaticBinary.hxx"
  41
  42 namespace simgear {
  43
  44 void
  45 BVHLineSegmentVisitor::apply(BVHGroup& group)
  46 {
  47     if (!intersects(_lineSegment, group.getBoundingSphere()))
  48         return;
  49     group.traverse(*this);
  50 }
  51
  52 void
  53 BVHLineSegmentVisitor::apply(BVHTransform& transform)
  54 {
  55     if (!intersects(_lineSegment, transform.getBoundingSphere()))
  56         return;
  57
  58     bool haveHit = _haveHit;
  59     _haveHit = false;
  60
  61     // Push the line segment
  62     SGLineSegmentd lineSegment = getLineSegment();
  63     _lineSegment = transform.lineSegmentToLocal(lineSegment);
  64
  65     transform.traverse(*this);
  66
  67     if (_haveHit) {
  68         _linearVelocity = transform.vecToWorld(_linearVelocity);
  69         _angularVelocity = transform.vecToWorld(_angularVelocity);
  70         SGVec3d point(transform.ptToWorld(_lineSegment.getEnd()));
  71         _lineSegment.set(lineSegment.getStart(), point);
  72         _normal = transform.vecToWorld(_normal);
  73     } else {
  74         _lineSegment = lineSegment;
  75         _haveHit = haveHit;
  76     }
  77 }
  78
  79 void
  80 BVHLineSegmentVisitor::apply(BVHMotionTransform& transform)
  81 {
  82     if (!intersects(_lineSegment, transform.getBoundingSphere()))
  83         return;
  84
  85     bool haveHit = _haveHit;
  86     _haveHit = false;
  87
  88     // Push the line segment
  89     SGLineSegmentd lineSegment = getLineSegment();
  90     SGMatrixd toLocal = transform.getToLocalTransform(_time);
  91     _lineSegment = lineSegment.transform(toLocal);
  92
  93     transform.traverse(*this);
  94
  95     if (_haveHit) {
  96         SGMatrixd toWorld = transform.getToWorldTransform(_time);
  97         SGVec3d localStart = _lineSegment.getStart();
  98         _linearVelocity += transform.getLinearVelocityAt(localStart);
  99         _angularVelocity += transform.getAngularVelocity();
 100         _linearVelocity = toWorld.xformVec(_linearVelocity);
 101         _angularVelocity = toWorld.xformVec(_angularVelocity);
 102         SGVec3d localEnd = _lineSegment.getEnd();
 103         _lineSegment.set(lineSegment.getStart(), toWorld.xformPt(localEnd));
 104         _normal = toWorld.xformVec(_normal);
 105         if (!_id)
 106             _id = transform.getId();
 107     } else {
 108         _lineSegment = lineSegment;
 109         _haveHit = haveHit;
 110     }
 111 }
 112
 113 void
 114 BVHLineSegmentVisitor::apply(BVHLineGeometry&)
 115 {
 116 }
 117
 118 void
 119 BVHLineSegmentVisitor::apply(BVHStaticGeometry& node)
 120 {
 121     if (!intersects(_lineSegment, node.getBoundingSphere()))
 122         return;
 123     node.traverse(*this);
 124 }
 125
 126 void
 127 BVHLineSegmentVisitor::apply(const BVHStaticBinary& node,
 128                              const BVHStaticData& data)
 129 {
 130     if (!intersects(SGLineSegmentf(_lineSegment), node.getBoundingBox()))
 131         return;
 132
 133     // The first box to enter is the one the startpoint is in.
 134     // this increases the probability, that on exit of that box we do not
 135     // even need to walk the other one, since the line segment is
 136     // then already short enough to not intersect the other one anymore.
 137     node.traverse(*this, data, _lineSegment.getStart());
 138 }
 139
 140 void
 141 BVHLineSegmentVisitor::apply(const BVHStaticTriangle& triangle,
 142                              const BVHStaticData& data)
 143 {
 144     SGTrianglef tri = triangle.getTriangle(data);
 145     SGVec3f point;
 146     if (!intersects(point, tri, SGLineSegmentf(_lineSegment), 1e-4f))
 147         return;
 148     setLineSegmentEnd(SGVec3d(point));
 149     _normal = SGVec3d(tri.getNormal());
 150     _linearVelocity = SGVec3d::zeros();
 151     _angularVelocity = SGVec3d::zeros();
 152     _material = data.getMaterial(triangle.getMaterialIndex());
 153     _id = 0;
 154     _haveHit = true;
 155 }
 156
 157
 158 }