Test of using glXGetProcAddress().

examples/osgmeshshader/osgmeshshader.cpp

@@ -18,6 +18,7 @@
 #include <osg/Shader>
 #include <osgUtil/Optimizer>
 
+
 class DrawMeshTasks : public osg::Drawable
 {
 public:
@@ -40,9 +41,17 @@ public:
     virtual void drawImplementation(osg::RenderInfo& renderInfo) const
     {
         const osg::GLExtensions* extensions = renderInfo.getState()->get<osg::GLExtensions>();
-        if (extensions->isMeshShaderSupported && extensions->glDrawMeshTasksNV)
+
+        void* (* my_glXGetProcAddress) (const GLchar *name);
+        osg::setGLExtensionFuncPtr(my_glXGetProcAddress, "glXGetProcAddress", "glXGetProcAddressARB");
+
+        void (GL_APIENTRY * my_glDrawMeshTasksNV) (GLuint first, GLuint count);
+
+        osg::convertPointer(my_glDrawMeshTasksNV, my_glXGetProcAddress("glDrawMeshTasksNV"));
+
+        if (extensions->isMeshShaderSupported && my_glDrawMeshTasksNV)
         {
-            extensions->glDrawMeshTasksNV(first, count);
+            my_glDrawMeshTasksNV(first, count);
         }
         else
         {
@@ -55,7 +64,6 @@ 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"
@@ -92,111 +100,14 @@ int main( int argc, char** argv )
     osg::ref_ptr<osg::Node> drawMesh = new DrawMeshTasks(0, 1);
     drawMesh->getOrCreateStateSet()->setAttribute( program.get() );
 
-
+    osgViewer::Viewer viewer(arguments);
-    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()->setUseModelViewAndProjectionUniforms(true);
-    gc->getState()->setUseVertexAttributeAliasing(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
-
-
-
---
-
-Under Linux the follow is sufficient to configure the OSG build for a GL3 core profile build:
-
-   cmake . -DOSG_GL3_AVAILABLE=ON \
-      -DOSG_GL1_AVAILABLE=OFF -DOSG_GL2_AVAILABLE=OFF -DOSG_GLES1_AVAILABLE=OFF -DOSG_GLES2_AVAILABLE=OFF \
-      -DOSG_GL_DISPLAYLISTS_AVAILABLE=OFF -DOSG_GL_FIXED_FUNCTION_AVAILABLE=OFF -DOSG_GL_MATRICES_AVAILABLE=OFF \
-      -DOSG_GL_VERTEX_ARRAY_FUNCS_AVAILABLE=OFF -DOSG_GL_VERTEX_FUNCS_AVAILABLE=OFF
-
-
-*/