Recently, a bug that caused excessive memory usage and slowness (specially in large models) in Workbench has been fixed in its canvas. From the testing I’ve done, the speed for displaying diagrams seems to scale much better and dragging around tables in large models is doable in an acceptable speed. This fix is in the upcoming releases of the 5.0 and 5.1 alpha versions of Workbench.
Apart from that, we’ve been doing some work on reintroducing OpenGL support to the Workbench canvas. Unlike the initial implementation, this time OpenGL is used directly instead of going through Cairo’s experimental (and not quite reliable) support through the Glitz layer. This means that in machines with a recent graphics card, hardware acceleration will be used and working with large diagrams will be a lot smoother and faster. Of course, software rendering backends (GDI+, Quartz and Xlib) will still be supported and used in case OpenGL is not the best option.
We still use Cairo to render everything (or most things) as before, but now the pre-rendered object bitmaps are uploaded to the video card and displayed through textures. Although the “software” rendering we were using was also hardware accelerated in most cases (because GDI+ et al are implemented with acceleration by the OS), using OpenGL textures seems much faster than blitting these bitmaps to screen in the old way. Naturally, this also opens the door for some totally useless and cool eye candy 🙂 But that’s for after we get the essentials done…
There are still problems to be worked out (some of the transparencies are not working well and there are some refreshing glitches), but you can try it with the --force-opengl-render option.
