Candlestick chart
Start ticks to watch the newest bar revise in place, drag the bar-width slider, and hover any bar to read its OHLC values. The strip along the bottom is a whole-history min/max/volume envelope, not just what is on screen.
This chart is a stress test for RingBuffer as much as it is a chart. RingBuffer shipped with the log viewer and had exactly one consumer, which means it was shaped entirely by log lines — and a primitive with one caller is just that caller’s internals in another file. A second, independent consumer found the gap immediately: a log line is history the moment it is written, but a candlestick’s newest bar is open, and every tick revises its high, low, close and volume. That is RingBuffer.overwrite, which now exists. Start the ticks and almost every one of them rewrites a single 24-byte record in place. The strip along the bottom is the whole-history envelope — min, max and volume across all 200,000 bars, reduced on the GPU, not the few hundred on screen.