add a very simple example for mdi with basevertex

examples/CMakeLists.txt

@@ -20,6 +20,7 @@ ELSE(ANDROID)
 
 IF(DYNAMIC_OPENSCENEGRAPH)
 
+    ADD_SUBDIRECTORY(osgsimpleMDI)
     ADD_SUBDIRECTORY(osg2cpp)
     ADD_SUBDIRECTORY(osganalysis)
     ADD_SUBDIRECTORY(osganimate)

examples/osgsimpleMDI/CMakeLists.txt

@@ -0,0 +1,7 @@
+#this file is automatically generated
+
+
+SET(TARGET_SRC osgsimpleMDI.cpp )
+
+#### end var setup  ###
+SETUP_EXAMPLE(osgsimpleMDI)

examples/osgsimpleMDI/osgsimpleMDI.cpp

@@ -0,0 +1,160 @@
+/* OpenSceneGraph example, osgtransformfeedback
+*
+*  Permission is hereby granted, free of charge, to any person obtaining a copy
+*  of this software and associated documentation files (the "Software"), to deal
+*  in the Software without restriction, including without limitation the rights
+*  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+*  copies of the Software, and to permit persons to whom the Software is
+*  furnished to do so, subject to the following conditions:
+*
+*  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+*  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+*  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+*  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+*  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+*  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+*  THE SOFTWARE.
+*/
+
+/* file:        examples/osgsimpleMDI/osgsimpleMDI.cpp
+* author:      Julien Valentin 2017-08-01
+* copyright:   (C) 2013
+* license:     OpenSceneGraph Public License (OSGPL)
+*
+* A simple example of mdi with basevertex
+*
+*/
+
+
+#include <osg/GL2Extensions>
+#include <osg/Notify>
+#include <osg/ref_ptr>
+#include <osg/Geode>
+#include <osg/Geometry>
+#include <osg/Point>
+#include <osg/Vec3>
+#include <osg/Vec4>
+#include <osg/Program>
+#include <osg/Shader>
+#include <osg/BlendFunc>
+
+#include <osg/Uniform>
+#include <osgViewer/Viewer>
+#include <osgViewer/ViewerEventHandlers>
+
+#include <osg/PrimitiveSetIndirect>
+#include <osg/BufferIndexBinding>
+
+
+
+
+///////////////////////////////////////////////////////////////////////////
+#define MAXX 100
+#define MAXY 100
+
+int main( int argc, char**argv )
+{
+
+    osg::ArgumentParser arguments(&argc,argv);
+
+    bool MDIenable=true;
+    if(arguments.read("--classic"))
+        MDIenable=false;
+
+    osg::Geode* root( new osg::Geode );
+    osg::BoundingBox bb;
+
+    osg::Vec3 corner;
+    osg::ref_ptr<osg::VertexBufferObject> vertbo=new osg::VertexBufferObject;
+    osg::ref_ptr<osg::VertexBufferObject> texbo=new osg::VertexBufferObject;
+    osg::ref_ptr<osg::ElementBufferObject> ebo=new osg::ElementBufferObject;
+
+    ///create empty mdi
+    osg::MultiDrawElementsIndirectUShort* mdi=new  osg::MultiDrawElementsIndirectUShort(osg::PrimitiveSet::TRIANGLE_STRIP);
+    osg::DefaultIndirectCommandDrawElements* mdicommands= new osg::DefaultIndirectCommandDrawElements();
+    mdi->setIndirectCommandArray(mdicommands);
+    mdi->setBufferObject(ebo);
+
+    osg::ref_ptr<osg::Geometry>	oldprHolder=new osg::Geometry();
+
+    osg::Vec3 myCoords[] =
+    {
+        osg::Vec3(0,0.0f,0.7f),
+        osg::Vec3(0,0.0f,0),
+        osg::Vec3(0.7,0.0f,0),
+        osg::Vec3(0.7f,0.0f,0.7f)
+    };
+
+    osg::Vec2 myTexCoords[] =
+    {
+        osg::Vec2(0,1),
+        osg::Vec2(0,0),
+        osg::Vec2(1,0),
+        osg::Vec2(1,1)
+    };
+    unsigned short myIndices[] =
+    {
+        0,
+        1,
+        3,
+        2
+    };
+    for(int j =0 ; j<MAXY; ++j) {
+        for(int i =0 ; i<MAXX; ++i) {
+
+            ///begin generate indexed quad
+            corner=osg::Vec3(i,0,j);
+            osg::Geometry* geom = new osg::Geometry();
+            geom->setUseVertexBufferObjects(true);
+            osg::Vec3Array * verts=new osg::Vec3Array(4,myCoords);
+            for(int z=0; z<4; z++)(*verts)[z]+=corner;
+            geom->setVertexArray(verts);
+            geom->setTexCoordArray(0,new osg::Vec2Array(4,myTexCoords));
+            geom->addPrimitiveSet(new osg::DrawElementsUShort(osg::PrimitiveSet::TRIANGLE_STRIP,4,myIndices));
+            ///end generate indexed quad
+
+            bb.expandBy(geom->getBoundingBox());
+
+            if(MDIenable) {
+                ///setup bos
+                geom->getVertexArray()->setBufferObject(vertbo);
+                geom->getTexCoordArray(0)->setBufferObject(texbo);
+                osg::DrawElementsUShort *dre = static_cast<osg::DrawElementsUShort*>(geom->getPrimitiveSet(0));
+                dre->setBufferObject(ebo);
+
+                ///keep old pr alive for indices upload purpose
+                oldprHolder->addPrimitiveSet(dre);
+                geom->removePrimitiveSet(0,1);
+
+                ///create indirect command
+                osg::DrawElementsIndirectCommand cmd;
+                cmd.count=4;
+                cmd.instanceCount=1;
+                cmd.firstIndex=root->getNumChildren()*4;
+                cmd.baseVertex=root->getNumChildren()*4;
+                mdicommands->push_back(cmd);
+
+                if(cmd.firstIndex==0) {
+                    ///only first geom have a mdi primset
+                    geom->addPrimitiveSet(mdi);
+                    ///avoid bound computation to fail because of the lack of support of basevertex in functors
+                    geom->setComputeBoundingBoxCallback(new osg::Drawable::ComputeBoundingBoxCallback);
+                }
+
+            }
+            root->addChild(geom);
+        }
+    }
+
+    if(MDIenable) {
+        ///override bounds
+        root->getDrawable(0)->setInitialBound(bb);
+        ///put it somewhere
+        root->setUserData( oldprHolder);
+    }
+
+    osgViewer::Viewer viewer;
+    viewer.addEventHandler(new osgViewer::StatsHandler);
+    viewer.setSceneData( root );
+    return viewer.run();
+}