add ComputeDispatch class

revoke glDispatch in PCProgram::useProgram
update example

examples/osgcomputeshaders/osgcomputeshaders.cpp

@@ -20,7 +20,7 @@
 // This example can work only if GL version is 4.3 or greater
 
 #include <osg/Texture2D>
-#include <osg/Geometry>
+#include <osg/ComputeDispatch>
 #include <osg/Geode>
 #include <osgDB/ReadFile>
 #include <osgGA/StateSetManipulator>
@@ -57,14 +57,12 @@ int main( int argc, char** argv )
     // The compute shader can't work with other kinds of shaders
     // It also requires the work group numbers. Setting them to 0 will disable the compute shader
     osg::ref_ptr<osg::Program> computeProg = new osg::Program;
-    computeProg->setComputeGroups( 512/16, 512/16, 1 );
     computeProg->addShader( new osg::Shader(osg::Shader::COMPUTE, computeSrc) );
 
     // Create a node for outputting to the texture.
     // It is OK to have just an empty node here, but seems inbuilt uniforms like osg_FrameTime won't work then.
     // TODO: maybe we can have a custom drawable which also will implement glMemoryBarrier?
-    osg::ref_ptr<osg::Node> sourceNode = osgDB::readRefNodeFile("axes.osgt");
-    if ( !sourceNode ) sourceNode = new osg::Node;
+    osg::ref_ptr<osg::Node> sourceNode = new osg::ComputeDispatch(512/16, 512/16, 1 );
     sourceNode->setDataVariance( osg::Object::DYNAMIC );
     sourceNode->getOrCreateStateSet()->setAttributeAndModes( computeProg.get() );
     sourceNode->getOrCreateStateSet()->addUniform( new osg::Uniform("targetTex", (int)0) );

include/osg/ComputeDispatch

@@ -0,0 +1,48 @@
+/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2014 Robert Osfield
+ * Copyright (C) 2017 Julien Valentin
+ *
+ * This library is open source and may be redistributed and/or modified under
+ * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
+ * (at your option) any later version.  The full license is in LICENSE file
+ * included with this distribution, and on the openscenegraph.org website.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * OpenSceneGraph Public License for more details.
+*/
+
+#ifndef OSG_COMPUTEDISPATCH
+#define OSG_COMPUTEDISPATCH 1
+
+#include <osg/Export>
+
+#include <osg/Geometry>
+
+namespace osg{
+    class OSG_EXPORT ComputeDispatch : public osg::Drawable
+    {
+        public:
+            ComputeDispatch(GLint numGroupsX=0, GLint numGroupsY=0, GLint numGroupsZ=0  ):
+                Drawable(),
+                _numGroupsX(numGroupsX),
+                _numGroupsY(numGroupsY),
+                _numGroupsZ(numGroupsZ)
+            {}
+
+            ComputeDispatch(const ComputeDispatch&,const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY);
+
+            META_Node(osg, ComputeDispatch);
+
+
+            virtual void drawImplementation(RenderInfo& renderInfo) const;
+             /** Set/get compute shader work groups */
+            void setComputeGroups( GLint numGroupsX, GLint numGroupsY, GLint numGroupsZ ) { _numGroupsX=numGroupsX,_numGroupsY=numGroupsY, _numGroupsZ=numGroupsZ; }
+            void getComputeGroups( GLint& numGroupsX, GLint& numGroupsY, GLint& numGroupsZ ) const{ numGroupsX=_numGroupsX; numGroupsY=_numGroupsY; numGroupsZ=_numGroupsZ; }
+        protected:
+            GLint _numGroupsX, _numGroupsY, _numGroupsZ;
+
+    };
+}
+#endif
+

src/osg/CMakeLists.txt

@@ -55,6 +55,7 @@ SET(TARGET_H
     ${HEADER_PATH}/ColorMaski
     ${HEADER_PATH}/ColorMatrix
     ${HEADER_PATH}/ComputeBoundsVisitor
+    ${HEADER_PATH}/ComputeDispatch
     ${HEADER_PATH}/ContextData
     ${HEADER_PATH}/ConvexPlanarOccluder
     ${HEADER_PATH}/ConvexPlanarPolygon
@@ -267,6 +268,7 @@ SET(TARGET_SRC
     ColorMaski.cpp
     ColorMatrix.cpp
     ComputeBoundsVisitor.cpp
+    ComputeDispatch.cpp
     ContextData.cpp
     ConvexPlanarOccluder.cpp
     ConvexPlanarPolygon.cpp

src/osg/ComputeDispatch.cpp

@@ -0,0 +1,12 @@
+#include <osg/ComputeDispatch>
+using namespace osg;
+
+
+ComputeDispatch::ComputeDispatch(const ComputeDispatch&o,const osg::CopyOp& copyop): Drawable(o,copyop), _numGroupsX(o._numGroupsX), _numGroupsY(o._numGroupsY), _numGroupsZ(o._numGroupsZ)
+{
+
+}
+
+void ComputeDispatch::drawImplementation(RenderInfo& renderInfo) const{
+    renderInfo.getState()->get<GLExtensions>()->glDispatchCompute(_numGroupsX, _numGroupsY, _numGroupsZ);
+}

src/osg/Program.cpp

@@ -1108,8 +1108,4 @@ Program::ProgramBinary* Program::PerContextProgram::compileProgramBinary(osg::St
 void Program::PerContextProgram::useProgram() const
 {
     _extensions->glUseProgram( _glProgramHandle  );
-    if ( _program->_numGroupsX>0 && _program->_numGroupsY>0 && _program->_numGroupsZ>0 )
-    {
-        _extensions->glDispatchCompute( _program->_numGroupsX, _program->_numGroupsY, _program->_numGroupsZ );
-    }
 }

src/osgWrappers/serializers/osg/ComputeDispatch.cpp

@@ -0,0 +1,36 @@
+#include <osg/ComputeDispatch>
+#include <osgDB/ObjectWrapper>
+#include <osgDB/InputStream>
+#include <osgDB/OutputStream>
+
+// _numGroupsX/Y/Z
+static bool checkComputeGroups( const osg::ComputeDispatch& attr )
+{
+    GLint numX = 0, numY = 0, numZ = 0;
+    attr.getComputeGroups( numX, numY, numZ );
+    return numX>0 && numY>0 && numZ>0;
+}
+
+static bool readComputeGroups( osgDB::InputStream& is, osg::ComputeDispatch& attr )
+{
+    GLint numX = 0, numY = 0, numZ = 0;
+    is >> numX >> numY >> numZ;
+    attr.setComputeGroups( numX, numY, numZ );
+    return true;
+}
+
+static bool writeComputeGroups( osgDB::OutputStream& os, const osg::ComputeDispatch& attr )
+{
+    GLint numX = 0, numY = 0, numZ = 0;
+    attr.getComputeGroups( numX, numY, numZ );
+    os << numX << numY << numZ << std::endl;
+    return true;
+}
+
+REGISTER_OBJECT_WRAPPER( ComputeDispatch,
+                         new osg::ComputeDispatch,
+                         osg::ComputeDispatch,
+                         "osg::Object osg::Node osg::Drawable osg::ComputeDispatch" )
+{
+        ADD_USER_SERIALIZER( ComputeGroups );  // _numGroupsX/Y/Z
+}