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How I failed to make a game: Raycasting on the GBA

(mcejp.github.io)
133 points mcejp | 1 comments | 15 Oct 24 22:53 UTC | HN request time: 0.235s | source
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eig ◴[17 Oct 24 19:05 UTC] No.41872754[source]▶
Shockingly enough it is actually possible to do decent ray casting and much more on the GBA despite the incredibly minimal compute budget.

Joshua Barretto has been working on a GBA port of Super Mario 64 with entire 3D levels, characters, and movements. In my opinion just incredible work:

https://youtu.be/9mUsgJ-HiDM

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nxobject ◴[18 Oct 24 12:04 UTC] No.41878607[source]▶
Amazing - a purely software rasterizer on 16MHz, no floating point, 16-bit data bus, at most 512k of RAM? That’s the original 68k! What’s everyone’s excuse for not getting SM64 running on a Macintosh Plus?
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1. 0xcde4c3db ◴[18 Oct 24 15:52 UTC] No.41880558[source]▶
I guess you're probably joking, but in case there's any actual confusion:

ARM7 is fully pipelined, and GBA connects it to 32K of on-chip zero-wait-state SRAM, so it's possible for optimized code to approach 16 MIPS with 32-bit operations. The original 68K is a multi-cycle processor and Mac Plus runs it at 8 MHz, which tops out at more like 2 MIPS for 16-bit operations, less for 32-bit operations (the ALUs are only 16-bit).