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 "BVHPageNode.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(BVHPageNode& pageNode)
  54 {
  55     if (!intersects(_lineSegment, pageNode.getBoundingSphere()))
  56         return;
  57     pageNode.traverse(*this);
  58 }
  59
  60 void
  61 BVHLineSegmentVisitor::apply(BVHTransform& transform)
  62 {
  63     if (!intersects(_lineSegment, transform.getBoundingSphere()))
  64         return;
  65
  66     bool haveHit = _haveHit;
  67     _haveHit = false;
  68
  69     // Push the line segment
  70     SGLineSegmentd lineSegment = getLineSegment();
  71     _lineSegment = transform.lineSegmentToLocal(lineSegment);
  72
  73     transform.traverse(*this);
  74
  75     if (_haveHit) {
  76         _linearVelocity = transform.vecToWorld(_linearVelocity);
  77         _angularVelocity = transform.vecToWorld(_angularVelocity);
  78         SGVec3d point(transform.ptToWorld(_lineSegment.getEnd()));
  79         _lineSegment.set(lineSegment.getStart(), point);
  80         _normal = transform.vecToWorld(_normal);
  81     } else {
  82         _lineSegment = lineSegment;
  83         _haveHit = haveHit;
  84     }
  85 }
  86
  87 void
  88 BVHLineSegmentVisitor::apply(BVHMotionTransform& transform)
  89 {
  90     if (!intersects(_lineSegment, transform.getBoundingSphere()))
  91         return;
  92
  93     bool haveHit = _haveHit;
  94     _haveHit = false;
  95
  96     // Push the line segment
  97     SGLineSegmentd lineSegment = getLineSegment();
  98     SGMatrixd toLocal = transform.getToLocalTransform(_time);
  99     _lineSegment = lineSegment.transform(toLocal);
 100
 101     transform.traverse(*this);
 102
 103     if (_haveHit) {
 104         SGMatrixd toWorld = transform.getToWorldTransform(_time);
 105         SGVec3d localStart = _lineSegment.getStart();
 106         _linearVelocity += transform.getLinearVelocityAt(localStart);
 107         _angularVelocity += transform.getAngularVelocity();
 108         _linearVelocity = toWorld.xformVec(_linearVelocity);
 109         _angularVelocity = toWorld.xformVec(_angularVelocity);
 110         SGVec3d localEnd = _lineSegment.getEnd();
 111         _lineSegment.set(lineSegment.getStart(), toWorld.xformPt(localEnd));
 112         _normal = toWorld.xformVec(_normal);
 113         if (!_id)
 114             _id = transform.getId();
 115     } else {
 116         _lineSegment = lineSegment;
 117         _haveHit = haveHit;
 118     }
 119 }
 120
 121 void
 122 BVHLineSegmentVisitor::apply(BVHLineGeometry&)
 123 {
 124 }
 125
 126 void
 127 BVHLineSegmentVisitor::apply(BVHStaticGeometry& node)
 128 {
 129     if (!intersects(_lineSegment, node.getBoundingSphere()))
 130         return;
 131     node.traverse(*this);
 132 }
 133
 134 void
 135 BVHLineSegmentVisitor::apply(const BVHStaticBinary& node,
 136                              const BVHStaticData& data)
 137 {
 138     if (!intersects(SGLineSegmentf(_lineSegment), node.getBoundingBox()))
 139         return;
 140
 141     // The first box to enter is the one the startpoint is in.
 142     // this increases the probability, that on exit of that box we do not
 143     // even need to walk the other one, since the line segment is
 144     // then already short enough to not intersect the other one anymore.
 145     node.traverse(*this, data, _lineSegment.getStart());
 146 }
 147
 148 void
 149 BVHLineSegmentVisitor::apply(const BVHStaticTriangle& triangle,
 150                              const BVHStaticData& data)
 151 {
 152     SGTrianglef tri = triangle.getTriangle(data);
 153     SGVec3f point;
 154     if (!intersects(point, tri, SGLineSegmentf(_lineSegment), 1e-4f))
 155         return;
 156     setLineSegmentEnd(SGVec3d(point));
 157     _normal = SGVec3d(tri.getNormal());
 158     _linearVelocity = SGVec3d::zeros();
 159     _angularVelocity = SGVec3d::zeros();
 160     _material = data.getMaterial(triangle.getMaterialIndex());
 161     _id = 0;
 162     _haveHit = true;
 163 }
 164
 165
 166 }