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Problem 2: Graphics artifacts (black rectangles)
Symptom: Once we had fixed the DWM-punting bug above, we unmasked the problem that Swing windows would sometimes be littered with black boxes or draw the content in the wrong place. The problems were intermittent and depended somewhat on the particular graphics operations that were taking place (scrolling or moving JInternalFrames around seemed particularly problematic).
Problem : Desktop Java ends up using both DirectX and GDI to draw content into a Java window. We use GDI for basic windowing functions such as creating the window and other heavyweight components that Swing uses underneath. We use DirectX to get some of the more advanced 2D capabilities that Swing benefits from, such as caching the back buffer in video memory for accelerated copies to the screen. This worked fine on Windows pre-Vista ; GDI would draw directly to the screen, Direct X would copy directly to the screen, and life was good. But in the new composited-desktop world of Vista, this system breaks down. GDI is now rendered in software into a GDI texture map, DirectX is rendered into a different texture map, and, like small kids crammed together into the back seat on a long car trip, they simply don't play well together. Our use of both rendering systems for the same windows simply causes mayhem in the Vista rendering system and artifacts on the screen. The response we got from Microsoft when we pointed out the issue was akin to "Ohhhhhh - you're doing that? That'll never work". See Greg Schechter's blog on the topic for more details.
Solution: The quickest solution was to simply disable our use of DirectX on Vista. We are basically forced to use one or the other: GDI or DirectX. We cannot avoid GDI because we need access to basic window system capabilities, so DirectX had to go. There is a more complete solution in the works (for Java SE 7) that will involve a much more complete implementation on top of Direct3D with a more involved and capable buffering system that will allow us to use DirectX in a much more Vista-friendly manner. But until we have finished that work (how is it going, Dmitri?) we will be using a software-rendering approach on Vista. The graphics performance geek in me is not overjoyed about the solution; of course I want to see as much hardware acceleration used as possible. All of the time. For everything. But in reality, typical Vista machines (which will be pretty beefy) running typical Swing applications (with basic, static GUIs) will run absolutely fine. In fact, given our basic level of acceleration so far, many current systems with decent CPUs (not just the high-end ones) run typical Swing applications faster than they would with this level of acceleration; it all depends on the combination of system resources and application requirements.

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