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First sprite multiplexer: where did sprite five go?

3 replies · opened JUN 8 ago

ORIGINAL TRANSMISSION
I have eight hardware sprites and twelve actors. The first split mostly works, except sprite five disappears whenever two actors share a Y position near the split.

I am sorting by Y and updating the registers in a raster IRQ. Is the usual beginner mistake simply scheduling the reuse too close?
REPLY #1
Very likely. Leave enough lines after the sprite finishes before changing its Y position, and watch what happens when several entries land on the same line.
REPLY #2
Log the sorted Y list to screen for one frame. Mine looked correct in memory until I noticed two entries had swapped only their pointers.
REPLY #3
Also test the ugly cases first: all actors clustered together, then actors entering from the top and bottom simultaneously.

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