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