A high-performance terminal rasterization and diffing engine.
Vellum is not a CLI framework. It is not a UI toolkit or a widget library. Vellum is an engine dedicated to solving one problem: How can we update the terminal screen with the least ANSI escape sequence overhead and CPU usage possible?
By optimizing the delta between frames, Vellum enables developers to implement complex, high-performance terminal animations and TUI components with near-zero overhead.
- Efficient: Focused on two primary goals: minimizing the byte-count sent to stdout and minimizing the CPU cycles required to calculate those changes.
- Portable: Written in modern, portable C17 with zero external dependencies beyond the standard C library.
- Zero-cost: No hidden memory allocations, no opaque state management, and no mandatory event loops.
- No input handling: Vellum is not concerned with keyboard or mouse input; it manages output only.
- No layout engine: Managing spatial logic and element positioning is the responsibility of the consumer. Vellum only renders what it is explicitly told to.
- No widgets: There are no buttons, textboxes, or complex UI elements: only primitive primitives such as text, lines, and boxes.