From eb59590d77bcb720e98a4fb87320065871b664db Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Tue, 28 Mar 2017 18:29:26 +0100
Subject: [PATCH] Added handling of large shapes

---
 examples/osgshape/osgshape.cpp | 50 ++++++++++++++++++++++++++--------
 src/osg/Shape.cpp              | 36 ++++++++++++++----------
 2 files changed, 61 insertions(+), 25 deletions(-)

diff --git a/examples/osgshape/osgshape.cpp b/examples/osgshape/osgshape.cpp
index 8fe695629..d82eb7821 100644
--- a/examples/osgshape/osgshape.cpp
+++ b/examples/osgshape/osgshape.cpp
@@ -33,7 +33,7 @@
 // for the grid data..
 #include "../osghangglide/terrain_coords.h"
 
-osg::Geode* createShapes()
+osg::Geode* createShapes(osg::ArgumentParser& arguments)
 {
     osg::Geode* geode = new osg::Geode();
 
@@ -70,17 +70,43 @@ osg::Geode* createShapes()
     geode->addDrawable(new osg::ShapeDrawable(new osg::Capsule(osg::Vec3(8.0f,0.0f,0.0f),radius,height),hints));
 
     osg::HeightField* grid = new osg::HeightField;
-    grid->allocate(38,39);
-    grid->setXInterval(0.28f);
-    grid->setYInterval(0.28f);
-
-    for(unsigned int r=0;r<39;++r)
+    if (arguments.read("--large"))
     {
-        for(unsigned int c=0;c<38;++c)
+        unsigned int numX = 512;
+        unsigned int numY = 512;
+        double sizeX = 10.0;
+        double sizeY = 10.0;
+        grid->allocate(numX,numY);
+        grid->setXInterval(sizeX/float(numX));
+        grid->setYInterval(sizeY/float(numY));
+
+        for(unsigned int r=0;r<numY;++r)
         {
-            grid->setHeight(c,r,vertex[r+c*39][2]);
+            for(unsigned int c=0;c<numX;++c)
+            {
+                double rx = double(c)/double(numX-1);
+                double ry = double(r)/double(numY-1);
+
+                grid->setHeight(c, r, 2.0*sin(rx*ry*4.0*osg::PI));
+            }
         }
     }
+    else
+    {
+        grid->allocate(38,39);
+        grid->setXInterval(0.28f);
+        grid->setYInterval(0.28f);
+
+        for(unsigned int r=0;r<39;++r)
+        {
+            for(unsigned int c=0;c<38;++c)
+            {
+                grid->setHeight(c,r,vertex[r+c*39][2]);
+            }
+        }
+    }
+
+
     geode->addDrawable(new osg::ShapeDrawable(grid));
 
     osg::ConvexHull* mesh = new osg::ConvexHull;
@@ -109,13 +135,15 @@ osg::Geode* createShapes()
     return geode;
 }
 
-int main(int, char **)
+int main(int argc, char **argv)
 {
+    osg::ArgumentParser arguments(&argc,argv);
+
     // construct the viewer.
-    osgViewer::Viewer viewer;
+    osgViewer::Viewer viewer(arguments);
 
     // add model to viewer.
-    viewer.setSceneData( createShapes() );
+    viewer.setSceneData( createShapes(arguments) );
 
     // add the state manipulator
     viewer.addEventHandler( new osgGA::StateSetManipulator(viewer.getCamera()->getOrCreateStateSet()) );
diff --git a/src/osg/Shape.cpp b/src/osg/Shape.cpp
index 67d4d71f8..e54dd8c2e 100644
--- a/src/osg/Shape.cpp
+++ b/src/osg/Shape.cpp
@@ -243,10 +243,15 @@ void BuildShapeGeometryVisitor::End()
 {
     if (_start_index>=_vertices->size()) return;
 
+    bool smallPrimitiveSet = _vertices->size() < 65536;
 
+    // OSG_NOTICE<<"BuildShapeGeometryVisitor::End() smallPrimitiveSet = "<<smallPrimitiveSet<<std::endl;
     if (_mode==GL_QUADS)
     {
-        osg::ref_ptr<osg::DrawElementsUShort> primitives = new osg::DrawElementsUShort(GL_TRIANGLES);
+        osg::ref_ptr<osg::DrawElements> primitives = smallPrimitiveSet ?
+            static_cast<osg::DrawElements*>(new osg::DrawElementsUShort(GL_TRIANGLES)) :
+            static_cast<osg::DrawElements*>(new osg::DrawElementsUInt(GL_TRIANGLES));
+
         _geometry->addPrimitiveSet(primitives.get());
 
         for(unsigned int i=_start_index; i<_vertices->size(); i+=4)
@@ -256,18 +261,21 @@ void BuildShapeGeometryVisitor::End()
             unsigned int p2 = i+2;
             unsigned int p3 = i+3;
 
-            primitives->push_back(p0);
-            primitives->push_back(p3);
-            primitives->push_back(p1);
+            primitives->addElement(p0);
+            primitives->addElement(p3);
+            primitives->addElement(p1);
 
-            primitives->push_back(p1);
-            primitives->push_back(p3);
-            primitives->push_back(p2);
+            primitives->addElement(p1);
+            primitives->addElement(p3);
+            primitives->addElement(p2);
         }
     }
     else if (_mode==GL_QUAD_STRIP)
     {
-        osg::ref_ptr<osg::DrawElementsUShort> primitives = new osg::DrawElementsUShort(GL_TRIANGLES);
+        osg::ref_ptr<osg::DrawElements> primitives = smallPrimitiveSet ?
+            static_cast<osg::DrawElements*>(new osg::DrawElementsUShort(GL_TRIANGLES)) :
+            static_cast<osg::DrawElements*>(new osg::DrawElementsUInt(GL_TRIANGLES));
+
         _geometry->addPrimitiveSet(primitives.get());
 
         for(unsigned int i=_start_index; i<_vertices->size()-2; i+=2)
@@ -277,13 +285,13 @@ void BuildShapeGeometryVisitor::End()
             unsigned int p2 = i+2;
             unsigned int p3 = i+3;
 
-            primitives->push_back(p0);
-            primitives->push_back(p2);
-            primitives->push_back(p1);
+            primitives->addElement(p0);
+            primitives->addElement(p2);
+            primitives->addElement(p1);
 
-            primitives->push_back(p1);
-            primitives->push_back(p2);
-            primitives->push_back(p3);
+            primitives->addElement(p1);
+            primitives->addElement(p2);
+            primitives->addElement(p3);
         }
     }
     else