FGFS-4.1/OpenSceneGraph
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Added use of GL_TRIANGLE_STRIP to cut down the size of the primitive indices required.

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git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/trunk@14476 16af8721-9629-0410-8352-f15c8da7e697
This commit is contained in:
Robert Osfield
2014-11-14 17:44:20 +00:00
parent bff5b0261b
commit 6661deeb24
1 changed files with 53 additions and 1 deletions
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54
examples/osgterrain/ShaderTerrain.cpp
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@@ -241,6 +241,58 @@ osg::ref_ptr<osg::Geometry> GeometryPool::getOrCreateGeometry(osgTerrain::Terrai
}
}
#if 1
bool smallTile = numVertices <= 16384;
osg::ref_ptr<osg::DrawElements> elements = smallTile ?
static_cast<osg::DrawElements*>(new osg::DrawElementsUShort(GL_TRIANGLE_STRIP)) :
static_cast<osg::DrawElements*>(new osg::DrawElementsUInt(GL_TRIANGLE_STRIP));
elements->reserveElements( (nx-1) * (ny-1) * 2 + (nx-1)*2*2 + (ny-1)*2*2 +(ny)*2);
geometry->addPrimitiveSet(elements.get());
// first row containing the skirt
int il = 0;
int iu = 0;
for(int c=0; c<nx; ++c)
{
il = c;
iu = il+nx+1;
elements->addElement(iu);
elements->addElement(il);
}
elements->addElement(il);
// center section
for(int r=0; r<ny-1; ++r)
{
il = nx+r*(nx+2);
iu = il+nx+2;
elements->addElement(iu);
for(int c=0; c<nx+2; ++c)
{
il = c+nx+r*(nx+2);
iu = il+nx+2;
elements->addElement(iu);
elements->addElement(il);
}
elements->addElement(il);
}
// top row containing skirt
il = nx+(ny-1)*(nx+2)+1;
iu = il+nx+1;
elements->addElement(iu);
for(int c=0; c<nx; ++c)
{
il = c+nx+(ny-1)*(nx+2)+1;
iu = il+nx+1;
elements->addElement(iu);
elements->addElement(il);
}
#else
bool smallTile = numVertices <= 16384;
osg::ref_ptr<osg::DrawElements> elements = smallTile ?
static_cast<osg::DrawElements*>(new osg::DrawElementsUShort(GL_QUADS)) :
@@ -285,7 +337,7 @@ osg::ref_ptr<osg::Geometry> GeometryPool::getOrCreateGeometry(osgTerrain::Terrai
elements->addElement(iu+1);
elements->addElement(iu);
}
#endif
if (locator)
{
matrix = locator->getTransform();