Rendering artifact during rapid pan (stale/partial tiles persist)

[diegospa99]

Summary

When panning rapidly (especially across a multi-puck TMA slide), tiles render inconsistently — some pucks appear with different brightness/contrast or partial fills, and edge-detail popups can get stuck on `loading...` mid-pan.

Symptoms

• During or right after a fast pan, adjacent pucks in the same view render with visually distinct brightness/intensity (some appear ~30% dimmer than expected, others appear correct)
• Looks like tile-loading order issue: stale tiles from a prior viewport linger, new tiles render on top in patches → uneven mosaic
• Resolves to a clean render after pan stops and tiles fully reload (a few seconds)
• The `EDGE` info popup can also show `loading...` while a click-target is being resolved against a still-loading region

Repro

1. Open a multi-puck Xenium TMA dataset
2. Zoom out to bird's-eye / overview level
3. Pan rapidly across the slide (mouse drag) or use the minimap to jump
4. Observe the patchy/inconsistent puck rendering during/just after the pan

Likely causes

• Tile fetch queue not cancelled on viewport change → late-arriving tiles paint stale data over fresh
• Cache eviction inconsistent across the pyramid levels currently visible
• No debounce on the edge-detail fetch when the click position is moving

Suggested fixes

• Cancel in-flight tile requests when viewport changes significantly
• Render a low-res placeholder while higher-res tiles load (instead of leaving stale tiles)
• Debounce or invalidate edge-detail queries when pan is active

Use case driving this

Currently doing a manuscript-level audit comparing LR mechanisms across multiple pucks of a Xenium TMA. Scrolling between pucks rapidly is the common path; the artifact makes brightness comparisons unreliable until the user pauses and waits for a clean render.

Versions

TissuePlex v0.2.0 (post-sync from RaredonLab/TissuePlex:dev on 2026-05-28)