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From Paul Martz and Geoff Michel, Paul updated Geoff's bug fixes to DelaunaryTraingulator.cpp to reflect recent tessellator spelling changes

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Robert Osfield 2007-01-15 09:56:36 +00:00
parent 0d8efac569
commit c53b597795
1 changed files with 69 additions and 24 deletions
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93
src/osgUtil/DelaunayTriangulator.cpp
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@ -23,7 +23,7 @@
#include <algorithm>
#include <set>
#include <map> //GWM July 2005 map is used in constraints.
#include <osgUtil/Tessellator> // Tessellator triangulates the constrained triangles
#include <osgUtil/Tessellator> // tessellator triangulates the constrained triangles
namespace osgUtil
{
@ -690,7 +690,46 @@ void DelaunayTriangulator::_uniqueifyPoints()
std::copy( temppts->begin(), temppts->end(), ci );
}
osgUtil::DelaunayConstraint *getconvexhull(osg::Vec3Array *points)
{ // fits the 'rubberband' around the 2D points for uses as a delaunay constraint.
osg::ref_ptr<osgUtil::DelaunayConstraint> dcconvexhull=new osgUtil::DelaunayConstraint; // make
// convex hull around all the points
// start from first point (at minx); proceed to last x and back
osg::Vec3Array *verts=new osg::Vec3Array; // the hull points
verts->push_back(*(points->begin()) ); // min x/y point is guaranteed to be on the hull
verts->push_back(*(points->begin()+1) ); // second low x/y point is first length to be tested
for (osg::Vec3Array::iterator vit=(points->begin()+2); vit!=points->end(); vit++) {
// check if point lies outside the current last line segment
bool ok=1;
while (ok && verts->size()>1) {
osg::Vec3 lastseg=*(verts->end()-2)-*(verts->end()-1);
osg::Vec3 thisseg=(*vit)-*(verts->end()-1);
float cosang=(lastseg^thisseg).z();
if (cosang <0.0) { // pop off last point - *vit is further out hull
verts->pop_back();
} else { ok=0;}
}
verts->push_back(*vit ); // next low x/y point is next length to be tested
// check if the previous external angle is >180 - then remove previous point
}
for (osg::Vec3Array::reverse_iterator rvit=points->rbegin()+1; rvit!=points->rend(); rvit++) {
// check if point lies outside the current last line segment
bool ok=1;
while (ok && verts->size()>1) {
osg::Vec3 lastseg=*(verts->end()-2)-*(verts->end()-1);
osg::Vec3 thisseg=(*rvit)-*(verts->end()-1);
float cosang=(lastseg^thisseg).z();
if (cosang <0.0) { // pop off last point - *rvit is further out hull
verts->pop_back();
} else { ok=0;}
}
if ((*rvit)!=*(verts->begin())) verts->push_back(*rvit ); // next low x/y point is next length to be tested
// check if the previous external angle is >180 - then remove previous point
}
dcconvexhull->setVertexArray(verts);
dcconvexhull->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::LINE_LOOP,0,verts->size()) );
return dcconvexhull.release();
}
bool DelaunayTriangulator::triangulate()
{
@ -748,6 +787,9 @@ bool DelaunayTriangulator::triangulate()
// pre-sort sample points
osg::notify(osg::INFO) << "DelaunayTriangulator: pre-sorting sample points\n";
std::sort(points->begin(), points->end(), Sample_point_compare);
// 24.12.06 add convex hull of points to force sensible outline.
osg::ref_ptr<osgUtil::DelaunayConstraint> dcconvexhull=getconvexhull(points);
addInputConstraint(dcconvexhull.get());
// set the last valid index for the point list
GLuint last_valid_index = points->size() - 1;
@ -756,8 +798,7 @@ bool DelaunayTriangulator::triangulate()
float minx = (*points)[0].x();
float maxx = (*points)[last_valid_index].x();
// find the minimum and maximum x values in the point list
// find the minimum and maximum y values in the point list
float miny = (*points)[0].y();
float maxy = miny;
@ -776,12 +817,14 @@ bool DelaunayTriangulator::triangulate()
// 16 Dec 2006 this increase in size encourages the supervertex triangles to be long and thin
// thus ensuring that the convex hull of the terrain points are edges in the delaunay triangulation
// the values do however result in a small loss of numerical resolution.
points_->push_back(osg::Vec3(minx - 2.0*(maxx - minx), miny - 1.0*(maxy - miny), 0));
points_->push_back(osg::Vec3(maxx + 1.0*(maxx - minx), miny - 1.0*(maxy - miny), 0));
points_->push_back(osg::Vec3(maxx + 1.0*(maxx - minx), maxy + 2.0*(maxy - miny), 0));
// add supertriangle to triangle list
points_->push_back(osg::Vec3(minx - .10*(maxx - minx), miny - .10*(maxy - miny), 0));
points_->push_back(osg::Vec3(maxx + .10*(maxx - minx), miny - .10*(maxy - miny), 0));
points_->push_back(osg::Vec3(maxx + .10*(maxx - minx), maxy + .10*(maxy - miny), 0));
points_->push_back(osg::Vec3(minx - .10*(maxx - minx), maxy + .10*(maxy - miny), 0));
// add supertriangles to triangle list
triangles.push_back(Triangle(last_valid_index+1, last_valid_index+2, last_valid_index+3, points));
triangles.push_back(Triangle(last_valid_index+4, last_valid_index+1, last_valid_index+3, points));
// begin triangulation
@ -806,7 +849,7 @@ bool DelaunayTriangulator::triangulate()
next_j = j;
++next_j;
// compute the circumcircle
// get the circumcircle (x,y centre & radius)
osg::Vec3 cc = j->get_circumcircle();
// OPTIMIZATION: since points are pre-sorted by the X component,
@ -816,7 +859,8 @@ bool DelaunayTriangulator::triangulate()
// original code used r^2 and needed to test xdist*xdist>cc.z && i->x()>cc.x().
if ((xdist ) > cc.z() )
{
discarded_tris.push_back(*j);
discarded_tris.push_back(*j); // these are not needed for further tests as no more
// points will ever lie inside this triangle.
triangles.erase(j);
}
else
@ -994,14 +1038,15 @@ bool DelaunayTriangulator::triangulate()
for (tri=triangles.begin(); tri!=triangles.end(); )
{
bool deleted=false;
for (std::vector<const Triangle *>::const_iterator deleteTri=trisToDelete.begin();
deleteTri!=trisToDelete.end(); deleteTri++)
for (std::vector<const Triangle *>::iterator deleteTri=trisToDelete.begin();
deleteTri!=trisToDelete.end(); )
{
if (&(*tri)==*deleteTri)
{
deleted=true;
tri=triangles.erase(tri);
}
deleteTri=trisToDelete.erase(deleteTri); // 24.12.06 remove from delete list.
} else {deleteTri++; }
}
if (!deleted) ++tri;
}
@ -1019,7 +1064,7 @@ bool DelaunayTriangulator::triangulate()
// then these may not be the last vertices in the list.
// } else { // remove 3 super-triangle vertices more completely, moving any reference indices down.
Triangle_list::iterator tri;
GLuint supertriend = last_valid_index+3;
GLuint supertriend = last_valid_index+4;
for (tri=triangles.begin(); tri!=triangles.end();)
{ // look for triangles using the supertriangle indices or >super indices and move down by 3.
if ((tri->a() > last_valid_index && tri->a() <= supertriend) ||
@ -1027,21 +1072,21 @@ bool DelaunayTriangulator::triangulate()
(tri->c() > last_valid_index && tri->c() <= supertriend )) {
tri=triangles.erase(tri);
} else { // move down by 3 tests
if (tri->a() > last_valid_index) { // move down 3
tri->incrementa(-3);
if (tri->a() > last_valid_index) { // move index down 4
tri->incrementa(-4);
}
if (tri->b() > last_valid_index) { // move down 3
tri->incrementb(-3);
if (tri->b() > last_valid_index) { // move down 4
tri->incrementb(-4);
}
if (tri->b() > last_valid_index) { // move down 3
tri->incrementc(-3);
if (tri->c() > last_valid_index) { // move down 4 -- correction 21.12.06- was b() should test index c()
tri->incrementc(-4);
}
++tri; // only increment tri here as the other path increments when set tri=triangles.erase.
++tri; // only increment tri here as the other path increments tri when tri=triangles.erase.
}
}
// remove 3 supertriangle vertices from points. They may not be the last vertices in points if
// extra points have been inserted by the constraint re-triangulation.
points->erase(points->begin()+last_valid_index+1,points->begin()+last_valid_index+4);
points->erase(points->begin()+last_valid_index+1,points->begin()+last_valid_index+5);
//last_valid_index = points->size()-1; // the last valid vertex is last point.
// end of dec 2006 changes.
@ -1267,7 +1312,7 @@ osg::Vec3Array* DelaunayConstraint::getPoints(const osg::Vec3Array *points)
void DelaunayConstraint::handleOverlaps(void)
{
// use Tessellator to interpolate crossing vertices.
// use tessellator to interpolate crossing vertices.
osg::ref_ptr<osgUtil::Tessellator> tscx=new osgUtil::Tessellator; // this assembles all the constraints
tscx->setTessellationType(osgUtil::Tessellator::TESS_TYPE_GEOMETRY);
tscx->setBoundaryOnly(true);