Termy
Developer

Render Metrics

Debug terminal rendering performance.

Termy ships a debug-only render metrics overlay for diagnosing rendering churn.

Enable

RUST_LOG=info TERMY_RENDER_METRICS=1 cargo run -p termy

Metrics logs are gated on debug_assertions; --release builds will not emit render_metrics lines.

Counters

CounterMeaning
fullFull per-pane cell cache rebuild decisions
partialDirty-span patch decisions
reuseNo cell cache update needed
dirty_spanNumber of dirty spans consumed during partial updates
patched_cellNumber of cells patched from dirty spans
grid_paint / shape_linePaint + text shaping work that interval

Sanity check

During cursor blink, full should stay near 0. Small partial or reuse values are expected depending on reported terminal damage.

Benchmarks (macOS only)

cargo run -p xtask -- benchmark-compare

Requires xctrace / Activity Monitor. Not supported on Linux or Windows.

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