This class provides functions to manage OpenGL device contexts.

Starting with Open Inventor 8.5, the application can control sharing of OpenGL contexts (previously this was done internally for rendering contexts). When OpenGL contexts are shared it means that display lists, texture objects, buffer objects, etc created in any context in that share group can be used by any other context in that group. This saves time and memory when rendering into multiple windows, buffers, etc.

In a typical Open Inventor application an OpenGL device context is created automatically by the viewer class and is managed automatically by the viewer for rendering and other operations involving the GPU. However this context is only made current when the viewer is actively using it, for example to render the scene graph. (Prior to Open Inventor 8.5, the viewer made its OpenGL context "current" and this context remained current even when the viewer was not actively rendering the scene graph. This was convenient in some cases, but could conflict with application strategies for managing OpenGL contexts.)

Do not assume that any OpenGL context is current. If you need a current OpenGL context, for example to create an OIV.Inventor.Devices.SoGpuBufferObject, () and () an OIV.Inventor.Devices.SoGLContext object.

If your application uses an Open Inventor viewer, the viewer's rendering context can be made current using the viewer's bindNormalContext() method and released using the viewer's unbindNormalContext() method. This context can also be queried using the viewer's getNormalSoContext() method.

If you do not have (or do not have access to) a viewer, you can create a context by creating an OIV.Inventor.Devices.SoGLContext object. In almost all cases, calling the constructor with a true value will create a context that is in a share group with the rendering context. In other words, resources such as textures and buffer objects are shared between these contexts and can be used in any of the contexts in the share group. For example:

SoGLContext glContext = new SoGLContext(true);
glContext.Bind();
   SoGpuBufferObject gpuBuffer = new SoGpuBufferObject( SoGpuBufferObject.BufferAccessFrequencies.STATIC, SoGpuBufferObject.BufferAccessNatures.SHARED );
glContext.Unbind();

SoGLContext context = SoGLContext.GetCurrent( true );
if (context != null)
   context.SetNoGLContextDelete(); // Context is managed by someone else
else
   context = new SoGLContext( true );
context.Bind();
   . . .
context.Unbind();

Reference