From Paul Martz, example demonstating new draw instanced primitive funcitonality.

examples/CMakeLists.txt

@@ -32,6 +32,7 @@ IF(DYNAMIC_OPENSCENEGRAPH)
     ADD_SUBDIRECTORY(osgdelaunay)
     ADD_SUBDIRECTORY(osgdepthpartition)
     ADD_SUBDIRECTORY(osgdepthpeeling)
+    ADD_SUBDIRECTORY(osgdrawinstanced)
     ADD_SUBDIRECTORY(osgdistortion)
     ADD_SUBDIRECTORY(osgfadetext)
     ADD_SUBDIRECTORY(osgfont)

examples/osgdrawinstanced/CMakeLists.txt

@@ -0,0 +1,4 @@
+SET(TARGET_SRC osgdrawinstanced.cpp )
+
+#### end var setup  ###
+SETUP_EXAMPLE(osgdrawinstanced)

examples/osgdrawinstanced/osgdrawinstanced.cpp

@@ -0,0 +1,148 @@
+/* OpenSceneGraph example, osgdrawinstanced.
+*
+*  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.
+*/
+//
+// This code is copyright (c) 2008 Skew Matrix Software LLC. You may use
+// the code under the licensing terms described above.
+//
+
+#include <osgDB/ReadFile>
+#include <osgViewer/Viewer>
+#include <osg/Geometry>
+#include <osg/Texture2D>
+
+#include <osgDB/WriteFile>
+
+#include <iostream>
+
+void
+createDAIGeometry( osg::Geometry& geom, int nInstances=1 )
+{
+    const float halfDimX( .5 );
+    const float halfDimZ( .5 );
+
+    osg::Vec3Array* v = new osg::Vec3Array;
+    v->resize( 4 );
+    geom.setVertexArray( v );
+
+    // Geometry for a single quad.
+    (*v)[ 0 ] = osg::Vec3( -halfDimX, 0., -halfDimZ );
+    (*v)[ 1 ] = osg::Vec3( halfDimX, 0., -halfDimZ );
+    (*v)[ 2 ] = osg::Vec3( halfDimX, 0., halfDimZ );
+    (*v)[ 3 ] = osg::Vec3( -halfDimX, 0., halfDimZ );
+
+    // Use the DrawArraysInstanced PrimitiveSet and tell it to draw 1024 instances.
+    geom.addPrimitiveSet( new osg::DrawArrays( GL_QUADS, 0, 4, nInstances ) );
+}
+
+
+osg::StateSet*
+createStateSet()
+{
+    osg::ref_ptr< osg::StateSet > ss = new osg::StateSet;
+
+    // Create a vertex program that references the gl_InstanceID to
+    // render each instance uniquely. gl_InstanceID will be in the range
+    // 0 to numInstances-1 (1023 in our case).
+    std::string vertexSource =
+        "uniform sampler2D osgLogo; \n"
+        "uniform float osg_SimulationTime; \n"
+
+        "void main() \n"
+        "{ \n"
+            // Using the instance ID, generate "texture coords" for this instance.
+            "vec2 tC; \n"
+            "const float r = gl_InstanceID / 32.; \n"
+            "tC.s = fract( r ); tC.t = floor( r ) / 32.; \n"
+            // Get the color from the OSG logo.
+            "gl_FrontColor = texture2D( osgLogo, tC ); \n"
+
+            // Use the (scaled) tex coord to translate the position of the vertices.
+            "vec4 pos = vec4( tC.s * 48., 0., tC.t * 48., 1. ); \n"
+
+            // Compute a rotation angle from the instanceID and elapsed time.
+            "float timeOffset = gl_InstanceID / (32. * 32.); \n"
+            "float angle = ( osg_SimulationTime - timeOffset ) * 6.283; \n"
+            "float sa = sin( angle ); \n"
+            "float ca = cos( angle ); \n"
+            // New orientation, rotate around z axis.
+            "vec4 newX = vec4( ca, sa, 0., 0. ); \n"
+            "vec4 newY = vec4( sa, ca, 0., 0. ); \n"
+            "vec4 newZ = vec4( 0., 0., 1., 0. ); \n"
+            "mat4 mV = mat4( newX, newY, newZ, pos ); \n"
+            "gl_Position = ( gl_ModelViewProjectionMatrix * mV * gl_Vertex ); \n"
+        "} \n";
+
+    osg::ref_ptr< osg::Shader > vertexShader = new osg::Shader();
+    vertexShader->setType( osg::Shader::VERTEX );
+    vertexShader->setShaderSource( vertexSource );
+
+    osg::ref_ptr< osg::Program > program = new osg::Program();
+    program->addShader( vertexShader.get() );
+
+    ss->setAttribute( program.get(),
+        osg::StateAttribute::ON | osg::StateAttribute::PROTECTED );
+
+    osg::ref_ptr< osg::Image> iLogo = osgDB::readImageFile( "Images/osg128.png" );
+    if( !iLogo.valid() )
+    {
+        osg::notify( osg::ALWAYS ) << "Can't open image file osg128.png" << std::endl;
+        return( NULL );
+    }
+    osg::Texture2D* texLogo = new osg::Texture2D( iLogo );
+    texLogo->setFilter( osg::Texture2D::MIN_FILTER, osg::Texture2D::LINEAR );
+    texLogo->setFilter( osg::Texture2D::MAG_FILTER, osg::Texture2D::LINEAR );
+
+    ss->setTextureAttribute( 0, texLogo );
+
+    osg::ref_ptr< osg::Uniform > texLogoUniform =
+        new osg::Uniform( "osgLogo", 0 );
+    ss->addUniform( texLogoUniform.get() );
+
+    return( ss.release() );
+}
+
+
+int main( int argc, char **argv )
+{
+    // Make a scene graph consisting of a single Geode, containing
+    // a single Geometry, and a single PrimitiveSet.
+    osg::ref_ptr< osg::Geode > geode = new osg::Geode;
+
+    osg::ref_ptr< osg::Geometry > geom = new osg::Geometry;
+    // Configure the Geometry for use with EXT_draw_arrays:
+    // DL off and buffer objects on.
+    geom->setUseDisplayList( false );
+    geom->setUseVertexBufferObjects( true );
+    // OSG has no clue where out vertex shader will place the geometric data,
+    // so specify an initial bound to allow proper culling and near/far computation.
+    osg::BoundingBox bb( -1., -.1, -1., 49., 1., 49. );
+    geom->setInitialBound( bb );
+    // Add geometric data and the PrimitiveSet. Specify numInstances as 32*32 or 1024.
+    createDAIGeometry( *geom, 32*32 );
+    geode->addDrawable( geom );
+
+    // Create a StateSet to render the instanced Geometry.
+    osg::ref_ptr< osg::StateSet > ss = createStateSet();
+    geode->setStateSet( ss.get() );
+
+    // osgDB::writeNodeFile(*geode, "instanced.osg");
+
+    osgViewer::Viewer viewer;
+    viewer.setSceneData( geode.get() );
+    return viewer.run();
+}