Post #2762163
2026-04-12 18:05 UTC
@halcy@icosahedron.website it's because of a regular fetch not having already happened, and tile/map index/data latches being reset to 0 as a consequence
it also upsets the horizontal-pixel-inside-a-tile counter, but in a way I don't fully understand. the T/Y graphic is declared as this in the demo: https://codeberg.org/PoroCYon/emulator-examination/src/branch/main/arm9/source/main_ntr.c#L37-L46 , but it gets displayed correctly 'somehow'. it's not just by rotating the columns around, some get duplicated and others don't get shown at all
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@pcy@icosahedron.website 2026-04-12 18:10
@halcy@icosahedron.website another fun bonus detail is that it's possible to disable an affine background for one bus cycle when its internal UV coord gets updated, and then reenable it the next cycle. if you time it correctly (I haven't figured out the exact timing yet), it's possible to always keep the background layer as visible, but have it repeat the previous pixel due to the UV getting stuck. there's also one cycle during hblank where it updates the Y-axis UV instead, making it repeat whole scanlines instead of pixels