Added MESH and TASK shader enums to osg::Shader.

Added beginings of osgmeshshader example.

examples/osgmeshshader/CMakeLists.txt

@@ -0,0 +1,3 @@
+SET(TARGET_SRC osgmeshshader.cpp )
+
+SETUP_EXAMPLE(osgmeshshader)

examples/osgmeshshader/osgmeshshader.cpp

@@ -0,0 +1,190 @@
+// This is public domain software and comes with
+// absolutely no warranty. Use of public domain software
+// may vary between counties, but in general you are free
+// to use and distribute this software for any purpose.
+
+
+// Example: OSG using an OpenGL 3.1 context.
+// The comment block at the end of the source describes building OSG
+// for use with OpenGL 3.x.
+
+#include <osgViewer/Viewer>
+#include <osgDB/ReadFile>
+#include <osg/GraphicsContext>
+#include <osg/Camera>
+#include <osg/Viewport>
+#include <osg/StateSet>
+#include <osg/Program>
+#include <osg/Shader>
+#include <osgUtil/Optimizer>
+
+class DrawMeshTasks : public osg::Drawable
+{
+public:
+
+    DrawMeshTasks() :
+        first(0),
+        count(0)
+    {
+    }
+
+    DrawMeshTasks(GLuint in_first, GLuint in_count) :
+        first(in_first),
+        count(in_count)
+    {
+    }
+
+    GLuint first;
+    GLuint count;
+
+    virtual void drawImplementation(osg::RenderInfo& renderInfo) const
+    {
+        const osg::GLExtensions* extensions = renderInfo.getState()->get<osg::GLExtensions>();
+        if (extensions->isMeshShaderSupported && extensions->glDrawMeshTasksNV)
+        {
+            extensions->glDrawMeshTasksNV(first, count);
+        }
+        else
+        {
+            OSG_NOTICE<<"glDrawMeshTasksNV not supported. "<<std::endl;
+        }
+    }
+};
+
+int main( int argc, char** argv )
+{
+    osg::ArgumentParser arguments( &argc, argv );
+
+
+    static const char* meshSource = \
+        "#version 450 \n"
+        "#extension GL_NV_mesh_shader : enable\n"
+        "layout(local_size_x = 3) in;"
+        "layout(max_vertices = 64) out;"
+        "layout(max_primitives = 126) out;"
+        "layout(triangles) out;"
+        "const vec3 vertices[3] = {vec3(-1,-1,0), vec3(1,-1,0), vec3(0,1,0)};"
+        "void main()"
+        "{"
+            "uint id = gl_LocalInvocationID.x;"
+            "gl_MeshVerticesNV[id].gl_Position = vec4(vertices[id], 2);"
+            "gl_PrimitiveIndicesNV[id] = id;"
+            "gl_PrimitiveCountNV = 1;"
+        "}";
+
+
+    static const char* fragmentSource = \
+        "#version 450 \n"
+        "#extension GL_NV_fragment_shader_barycentric : enable\n"
+        "out vec4 color;"
+        "void main()"
+        "{"
+            "color = vec4(gl_BaryCoordNV, 1.0);"
+        "}";
+
+    osg::ref_ptr<osg::Shader> vShader = new osg::Shader( osg::Shader::MESH, meshSource );
+    osg::ref_ptr<osg::Shader> fShader = new osg::Shader( osg::Shader::FRAGMENT, fragmentSource );
+
+    osg::ref_ptr<osg::Program> program = new osg::Program;
+    program->addShader( vShader.get() );
+    program->addShader( fShader.get() );
+
+    osg::ref_ptr<osg::Node> drawMesh = new DrawMeshTasks(0, 1);
+    drawMesh->getOrCreateStateSet()->setAttribute( program.get() );
+
+
+    const int width( 800 ), height( 450 );
+    const std::string version( "4.6" );
+    osg::ref_ptr< osg::GraphicsContext::Traits > traits = new osg::GraphicsContext::Traits();
+    traits->x = 20; traits->y = 30;
+    traits->width = width; traits->height = height;
+    traits->windowDecoration = true;
+    traits->doubleBuffer = true;
+    traits->glContextVersion = version;
+    traits->readDISPLAY();
+    traits->setUndefinedScreenDetailsToDefaultScreen();
+    osg::ref_ptr< osg::GraphicsContext > gc = osg::GraphicsContext::createGraphicsContext( traits.get() );
+    if( !gc.valid() )
+    {
+        osg::notify( osg::FATAL ) << "Unable to create OpenGL v" << version << " context." << std::endl;
+        return( 1 );
+    }
+
+    osgViewer::Viewer viewer;
+
+    // Create a Camera that uses the above OpenGL context.
+    osg::Camera* cam = viewer.getCamera();
+    cam->setGraphicsContext( gc.get() );
+    // Must set perspective projection for fovy and aspect.
+    cam->setProjectionMatrix( osg::Matrix::perspective( 30., (double)width/(double)height, 1., 100. ) );
+    // Unlike OpenGL, OSG viewport does *not* default to window dimensions.
+    cam->setViewport( new osg::Viewport( 0, 0, width, height ) );
+
+    viewer.setSceneData( drawMesh );
+    viewer.setLight( 0 );
+    viewer.setLightingMode( osg::View::NO_LIGHT );
+
+    // for non GL3/GL4 and non GLES2 platforms we need enable the osg_ uniforms that the shaders will use,
+    // you don't need thse two lines on GL3/GL4 and GLES2 specific builds as these will be enable by default.
+    gc->getState()->setUseModelViewAndProjectionUniforms(true);
+    gc->getState()->setUseVertexAttributeAliasing(true);
+
+    return( viewer.run() );
+}
+
+/*
+
+Building OSG for OpenGL 3.x
+
+OSG currently support OpenGL 3.x on Windows. This comment block describes the
+necessary configuration steps.
+
+Get the draft gl3.h header file from OpenGL.org and put it in a folder called
+“GL3” somewhere on your hard drive. OSG includes this header as <GL3/gl3.h>. Get
+gl3.h from here:
+http://www.opengl.org/registry/
+
+Open the cmake-gui and load OSG's top-level CmakeLists.txt. You'll need to make
+several changes.
+
+ * Add the path to <GL3/gl3.h> to the CMake compiler flags, CMAKE_CXX_FLAGS and
+   CMAKE_CXX_FLAGS_DEBUG (for release and debug builds; others if you use other
+   build configurations). The text to add should look something like this:
+     /I “C:\GLHeader”
+   The folder GLHeader should contain a subfolder GL3, which in turn contains
+   gl3.h.
+
+ * Enable the following CMake variable:
+     OSG_GL3_AVAILABLE
+
+ * Disable the following CMake variables:
+     OSG_GL1_AVAILABLE
+     OSG_GL2_AVAILABLE
+     OSG_GLES1_AVAILABLE
+     OSG_GLES2_AVAILABLE
+     OSG_GL_DISPLAYLISTS_AVAILABLE
+     OSG_GL_FIXED_FUNCTION_AVAILABLE
+     OSG_GL_MATRICES_AVAILABLE
+     OSG_GL_VERTEX_ARRAY_FUNCS_AVAILABLE
+     OSG_GL_VERTEX_FUNCS_AVAILABLE
+
+Create your project files in cmake-gui as usual, and build OSG as usual.
+
+If you have an external project that will depend on OSG built for OpenGL 3.x,
+you'll need to ensure your external project also uses the compiler include
+directives to find <GL3/gl3.h>.
+
+To verify your application is using a pure OpenGL 3.x context, set
+OSG_NOTIFY_LEVEL=INFO in the environment and check the console output. Context
+creation displays output such as the following:
+    GL3: Attempting to create OpenGL3 context.
+    GL3: version: 3.1
+    GL3: context flags: 0
+    GL3: profile: 0
+    GL3: context created successfully.
+
+When your app begins rendering, it displays information about the actual context
+it is using:
+    glVersion=3.1, isGlslSupported=YES, glslLanguageVersion=1.4
+
+*/

include/osg/Shader

@@ -96,6 +96,8 @@ class OSG_EXPORT Shader : public osg::Object
             GEOMETRY = GL_GEOMETRY_SHADER,
             FRAGMENT = GL_FRAGMENT_SHADER,
             COMPUTE = GL_COMPUTE_SHADER,
+            MESH = GL_MESH_SHADER_NV,
+            TASK = GL_TASK_SHADER_NV,
             UNDEFINED = -1
         };