Most trading apps draw charts with a general-purpose library. We removed ours and built the chart engine from scratch, because the things a serious trader wants, footprint and market profile among them, render nowhere else.
A camera over the data
The engine treats a chart as a camera over a continuous space. Four transforms map bar index and price to the screen and back, and the candles, drawings, crosshair, and gridlines all draw through them. Pan and zoom move the camera. Nothing gets rebuilt, so nothing desyncs, and older history scrolls in without the view jerking.
What it draws today
Live candlesticks off the feed, with historical bars from the engine and infinite scroll into the past. Candles, bars, hollow, Heikin-Ashi, line, area, and baseline series, plus a volume sub-pane on its own axis. Five price-scale modes: linear, log, percent, indexed, and inverted. A drawing toolbar and an indicator legend, with a moving-average pair in from the start.
What is coming
Footprint and market-profile charts are the reason the engine exists, and they are the next major phase. Renko, Kagi, point-and-figure, and range bars, comparison symbols, order and alert layers, and bar replay follow. Every built-in indicator will be readable as source, so editing one forks it to your own copy.