a7974f8e6f
This simplifies the vertex data uploading in the journal, and could improve performance. Modifying a VBO mid-scene could reqire synchronizing with the GPU or some form of shadowing/copying to avoid modifying data that the GPU is currently processing; the buffer was also being marked as GL_STATIC_DRAW which could have made things worse. Now we simply create a GL_STATIC_DRAW VBO for each flush and and delete it when we are finished.