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Nathanael Gentry

Lots of chop suey

Hey there!

My big showcase for the week’s work is a few scenes from the kids’ game Chop Suey, one of our primary Director 4 test cases:

Just a few weeks ago, Chop Suey ran at an almost unplayable crawl in ScummVM. Part of this was its reliance on Matte inks, for which I implemented a simple surface caching scheme and shaved about 20% off our buildbot’s target test time for Spaceship Warlock. This also made Chop Suey run much faster, though it still consumed CPU

Last week I called Chop Suey a Lingo-heavy game, and I was referring to how much it controls animation via puppets and the updateStage command. Because, as you saw, its cursors are bitmaps and certainly do not fit in the standard 16x16 Macintosh cursor box, Chop Suey introduces its own mouse update code and calls for the stage to be updated several dozen times each frame. Most of the inefficiencies were here.

I spent the early part of the week in much trial-and-error, working out the pieces of the renderer that were most inefficient under such repeated application. The idea is to do a little bit of work up front – checking flags and so forth – so the expense of redrawing a region of the screen is saved. (As I have realized, even when working on Chop Suey, very subtle bugs can arise from forgetting to check a rendering flag.) Even at usual framerates without much Lingo that doesn’t matter very much, but Lingo-heavy games like Chop Suey have shown dramatic improvement.

I also implemented another feature that is notable in Chop Suey by its absence. I said that Chop Suey does its own cursor handling. Well, the window manager was still drawing a regular cursor atop the bitmap, which looked pretty ugly. Near the end of the week, though, I added a flexible cursor class for the three cursor types Director can use: built-in cursors, cast (bitmap) cursors, and resource cursors. The last type is important for Majestic: Alien Encounter, but I haven’t seen custom cursors used much elsewhere. It was fun to implement, though. As a nice byproduct in Chop Suey, the default cursor is now properly turned off.

Oh, and I also spent most of a day trying to discover why some textboxes in Spaceship Warlock weren’t rendering properly, along with some other nettling MacGUI issues. The issue actually lay in the cast loading code, which I hadn’t touched much, but it’s always satisfying to squash a bug and learn more about the codebase in the process – even if your “fix” breaks other stuff. :)