As above really; working on this: cf. https://www.opengl.org/sdk/docs/man/html/glDebugMessageInsert.xhtml :-)
Review needed for -5-0: https://gerrit.libreoffice.org/18103 tdf#93529 - add glDebugMessageInsert wrappers to help with API tracing. https://gerrit.libreoffice.org/18104 tdf#93529 - use debug messages while rendering to break up the trace. This makes API tracing hugely easier =) and it'd be good to keep the branches in sync too.