DZ-Jay Posted October 24, 2015 Share Posted October 24, 2015 Compression. Pre-built 2x2 tiles, to cut down on the overall size of stored screen data. The result is data that is 25% of it's original size. The game engine reads each tile as an index, and uses a pointer to write the data to the background. An example: metatile_05: DATA $2916,$290E,$290E,$2916 In this case, given the 16-bit nature of the tile data. The result is 60 byte screens (no RLE), rather than the expected 480(?) bytes. This, combined with a shared metatile set of (currently) only 160 bytes, reduces the data size exponentially. I'm going to focus on developing the game engine for now. I'll work on this aspect of the design, later. I guess I never found the need to cut down on the size of tile data. There's plenty of ROM space on the Intellivision platform, and I rather not have to spend too much CPU time on decoding it, which is the bottleneck. You have a buffer in Graphics RAM (GRAM) of 64 cards. Each of your screens do not seem to use as much. You can load each screen from different tile sets when needed. For sprites, you can get away with dynamically loading cards as needed throughout their animation lifecyle, which allows you to use more GRAM for background details. Good luck. -dZ. Quote Link to comment Share on other sites More sharing options...
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