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From Marc Helbling, "please find the mergeTriangleStrip code merged in osgUtil::TriStripVisitor.

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I've removed the references to DrawArrays as we should no longer produce any.

Note that:
* as the name suggest, it only works for triangle strips but could probably be easily extended to quads
* the resulting primitive is not highly optimized; we could probably sort the strips in order to minimize the number of primitive restart
* as we may merge DrawElementsUInt and DrawElementUShort, the code will only generate DrawElementsUInt"


git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/trunk@14602 16af8721-9629-0410-8352-f15c8da7e697
This commit is contained in:
Robert Osfield
2014-12-15 17:15:21 +00:00
parent 811dde86c8
commit 117869d154
2 changed files with 78 additions and 1 deletions
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71
src/osgUtil/TriStripVisitor.cpp
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@@ -504,6 +504,10 @@ void TriStripVisitor::stripify(Geometry& geom)
}
}
if(_mergeTriangleStrips) {
mergeTriangleStrips(new_primitives);
}
geom.setPrimitiveSetList(new_primitives);
#if 0
@@ -527,6 +531,73 @@ void TriStripVisitor::stripify(Geometry& geom)
}
void TriStripVisitor::mergeTriangleStrips(osg::Geometry::PrimitiveSetList& primitives)
{
int nbtristrip = 0;
int nbtristripVertexes = 0;
for (unsigned int i = 0; i < primitives.size(); ++ i)
{
osg::PrimitiveSet* ps = primitives[i].get();
osg::DrawElements* de = ps->getDrawElements();
if (de && de->getMode() == osg::PrimitiveSet::TRIANGLE_STRIP)
{
++ nbtristrip;
nbtristripVertexes += de->getNumIndices();
}
}
if (nbtristrip > 0) {
osg::notify(osg::NOTICE) << "found " << nbtristrip << " tristrip, "
<< "total indices " << nbtristripVertexes
<< " should result to " << nbtristripVertexes + nbtristrip * 2
<< " after connection" << std::endl;
osg::DrawElementsUInt* ndw = new osg::DrawElementsUInt(osg::PrimitiveSet::TRIANGLE_STRIP);
for (unsigned int i = 0; i < primitives.size(); ++ i)
{
osg::PrimitiveSet* ps = primitives[i].get();
if (ps && ps->getMode() == osg::PrimitiveSet::TRIANGLE_STRIP)
{
osg::DrawElements* de = ps->getDrawElements();
if (de)
{
// if connection needed insert degenerate triangles
if (ndw->getNumIndices() != 0 && ndw->back() != de->getElement(0))
{
// duplicate last vertex
ndw->addElement(ndw->back());
// insert first vertex of next strip
ndw->addElement(de->getElement(0));
}
if (ndw->getNumIndices() % 2 != 0 ) {
// add a dummy vertex to reverse the strip
ndw->addElement(de->getElement(0));
}
for (unsigned int j = 0; j < de->getNumIndices(); j++) {
ndw->addElement(de->getElement(j));
}
}
}
}
for (int i = primitives.size() - 1 ; i >= 0 ; -- i)
{
osg::PrimitiveSet* ps = primitives[i].get();
// remove null primitive sets and all primitives that have been merged
// (i.e. all TRIANGLE_STRIP DrawElements)
if (!ps || (ps && ps->getMode() == osg::PrimitiveSet::TRIANGLE_STRIP))
{
primitives.erase(primitives.begin() + i);
}
}
primitives.insert(primitives.begin(), ndw);
}
}
void TriStripVisitor::stripify()
{
for(GeometryList::iterator itr=_geometryList.begin();