We have been running into what appears to be a corner case in the ShaderProgram. As most of you probably know each OpenSG object that needs to track a GL object ID registers it's OpenGL creation and destruction functors through Window::registerGLObject(). This registration returns a unique OpenSG ID for each registered object. This unique OSG is then used in each objects handleGL() and handleDestroy() methods to get the context specific OpenGL object ID from each window. (ex: win->getGLObjectId(getGLId())) The normal operation is that when an object is created for a window you call the OpenGL function and set the OpenGL object ID in the ID map. Then in handleDestroyGL() you clear this ID mapping by setting it back to zero. It is important to note that these OpenSG object IDs are intelligently reused when objects are created/destroyed.
The issue that we are running into is that the current ShaderProgram code relies on the shared OSG IDs to have their mappings in each window reset to zero by all other objects in the system. http://www.opensg.org/browser/trunk/Source/System/State/Shader/Base/OSGShaderProgram.cpp#L528 This causes a big problem because there are a number of places where these IDs are not being cleared correctly in their handleDestroyGL() equivalent function. I did a quick search and found the following locations where the mapping from OpenSG ID to OpenGL ID is not being reset to zero correctly when destroying the OpenGL object. http://www.opensg.org/browser/trunk/Source/System/NodeCores/Drawables/Geometry/Base/WS/OSGGeometry.cpp#L280 http://www.opensg.org/browser/trunk/Source/System/NodeCores/Drawables/Geometry/Base/WS/OSGGeometry.cpp#L359 http://www.opensg.org/browser/trunk/Source/System/State/Base/WS/OSGTextureObjChunk.cpp#L1487 http://www.opensg.org/browser/trunk/Source/System/Depreciated/State/OpenGL/OSGCubeTextureChunk.cpp#L242 http://www.opensg.org/browser/trunk/Source/System/State/OpenGL/OSGCubeTextureObjChunk.cpp#L253 http://www.opensg.org/browser/trunk/Source/System/Window/FrameBufferObjects/OSGFrameBufferObject.cpp#L576 http://www.opensg.org/browser/trunk/Source/System/NodeCores/Drawables/Geometry/Properties/OSGGeoMultiPropertyData.cpp#L221 http://www.opensg.org/browser/trunk/Source/System/NodeCores/Drawables/Geometry/Properties/OSGGeoProperty.cpp#L317 http://www.opensg.org/browser/trunk/Source/System/Window/FrameBufferObjects/OSGRenderBuffer.cpp#L242 http://www.opensg.org/browser/trunk/Source/System/NodeCores/Drawables/Nurbs/OSGSurface.cpp#L1880 Although I think that we should fix these locations so that the IDs are rest correctly, can the ShaderProgram code be changed to not have such a fragile requirement for checking the OpenGL ID against zero. I have attached a patch for an older revision of OpenSG 2.0 that relaxes this requirement and we have been using for a few weeks without any issues. Thank you, Aron Bierbaum
shader_program.diff
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