한국어

A terminal app that grows — GPU-accelerated terminal emulator written in Rust for macOS.

Design Goals

• Modular: Each module has a single responsibility. You don't need to know the VT parser to fix clipboard copy.
• Testable: Pure functions and state machines are verified with unit tests; module interactions with integration tests.
• Evolvable: Reversible structure makes it safe to change, grow, and evolve.

Features

• GPU Rendering — wgpu-based 2-pass rendering (background + glyphs)
• Korean Support — IME input with preedit overlay, wide character handling, D2Coding font
• Tabs — Cmd+T/W to open/close, Cmd+1-9 to switch, Cmd+Shift+[/] to cycle, click tab bar, new tabs inherit working directory
• VT Parsing — SGR attributes (bold, dim, italic, underline, strikethrough, inverse), 256/RGB color, cursor movement, screen clearing
• TUI App Support — Alternate screen, scroll regions, mouse tracking (SGR), bracketed paste, synchronized output, cursor visibility (DECTCEM)
• Scrollback — 10,000 line history, Cmd+PageUp/PageDown, draggable auto-hiding scrollbar
• Copy Mode — Vim-style copy mode (Cmd+Shift+C) with hjkl navigation
• Mouse Selection & Clipboard — Drag selection with wide character awareness, Cmd+C/V, Cmd+A to copy input line
• URL Highlight — Cmd+hover to underline and detect URLs
• Pomodoro Timer — 25min work / 3min break cycle with input blocking
• Response Timer — Per-tab command response time measurement
• Font Zoom — Cmd+=/- to adjust size (8pt–72pt)
• Box Drawing — Light, heavy, double, and rounded corner characters with geometric rendering
• Keyboard — xterm-style encoding, Shift/Ctrl/Alt modifier combinations, kitty keyboard protocol

Keyboard Shortcuts

Shortcut	Action
Cmd+N	New window
Cmd+T	New tab
Cmd+W	Close tab
Cmd+1–9	Switch to tab by number
Cmd+Shift+[ / ]	Previous / next tab
Cmd+C	Copy
Cmd+V	Paste
Cmd+A	Copy input line to clipboard
Cmd+= / Cmd+-	Zoom in / out
Cmd+PageUp/Down	Scroll one page
Cmd+Home / End	Scroll to top / bottom
Cmd+Click	Open URL under cursor
` or Cmd+Shift+C	Enter / exit copy mode

Copy Mode

Key	Action
j / k	Move 1 line down / up
h / l	Move 10 lines up / down
v	Toggle visual mode (multi-line selection)
Cmd+C	Copy selection and exit copy mode

Recent Changes

• Claude Code cursor position fix — Fixed cursor position issues when running Claude Code
• Composing language enter — Pressing Enter during IME composition (e.g. Korean) now commits the character and sends Enter simultaneously

Architecture

Key Input → Input Encoding → PTY
                              ↓
                           VT Parser
                              ↓
                             Grid
                              ↓
                        Render Commands
                              ↓
                         GPU Rendering → Screen

Shared Types

Data types shared by all modules (Cell, Color, KeyEvent, etc.). A common language so modules can talk to each other.

Input Encoding

Translates keystrokes into bytes the shell understands.

Ctrl+C → \x03 · Arrow Up → \x1b[A

PTY

PTY (Pseudo-Terminal) is a pipe between our app and the shell. Fools the shell into thinking it's connected to a real terminal.

\x03 → shell → \x1b[31mHello

VT Parser

Parses the raw bytes from the shell into structured commands.

\x1b[31mHi → [SetColor(Red), Print('H'), Print('i')]

Grid

A 2D grid of cells, like a spreadsheet. Stores each character with its position and style. Also keeps scrollback history.

[SetColor(Red), Print('H')] → grid[row=0][col=0] = 'H' (red)

Render Commands

Reads the grid and produces a draw list. Adds cursor, selection highlight, and IME overlay on top.

grid[0][0]='H'(red) → DrawCell { row:0, col:0, char:'H', fg:#FF0000, bg:#000000 }

GPU Rendering

Takes the draw list and paints pixels on screen using the GPU. Each character becomes a bitmap composited onto the window.

DrawCell { char:'H', fg:#FF0000 } → pixels on screen

macOS

Creates the window, receives mouse/keyboard events from the OS, and handles IME (Korean input).

App

The conductor. Connects all modules: keystrokes come in, shell output comes back, the grid updates, the screen redraws.

Build & Run

cargo build --release
cargo run -p growterm-app

Install as macOS App

./install.sh

Builds the release binary and installs growTerm.app to /Applications.

Test

cargo test

594+ tests (unit + integration).

Requirements

• Rust (stable)
• macOS (wgpu Metal backend)