# xorg_cli

A development tool for testing the xorg viewer sink. Opens an X11 window using GLFW/OpenGL, renders a test pattern at the chosen scale and anchor, and displays a text overlay showing the current date. The window stays open until the user presses Q, Escape, or closes it.

---

## Build

From the repository root:

```sh
make cli
```

The binary is placed in `build/cli/`.

Requires the GLFW, OpenGL, and libjpeg-turbo libraries. If compiled without `HAVE_GLFW`, the binary will print an error and exit.

---

## Usage

```sh
./xorg_cli [--pattern bars|ramp|grid]
           [--width N] [--height N]
           [--format yuv420|bgra]
           [--scale stretch|fit|fill|1:1]
           [--anchor center|topleft]
           [--x N] [--y N]
```

| Option | Default | Description |
|---|---|---|
| `--pattern` | `bars` | Test pattern to render |
| `--width N` | `1280` | Window width in pixels |
| `--height N` | `720` | Window height in pixels |
| `--format` | `yuv420` | Frame pixel format |
| `--scale` | `stretch` | How the frame fills the window |
| `--anchor` | `center` | Frame alignment within the window |
| `--x N` | `0` | Window X position on screen |
| `--y N` | `0` | Window Y position on screen |

### Scale modes

| Mode | Description |
|---|---|
| `stretch` | Fill the window, ignoring aspect ratio |
| `fit` | Largest rect that fits, preserving aspect ratio (black bars) |
| `fill` | Smallest rect that covers, preserving aspect ratio (crops edges) |
| `1:1` | Native pixel size, no scaling |

### Anchor modes

Anchor applies when the frame does not fill the window (fit, fill, 1:1 modes):

| Mode | Description |
|---|---|
| `center` | Centre the frame in the window |
| `topleft` | Align frame to the top-left corner |

### Example

```sh
./xorg_cli --pattern grid --scale fit --anchor center --width 1920 --height 1080
```

---

## Relationship to the Video Routing System

`xorg_cli` exercises the `xorg` module used by the video node for its display sink role. The same viewer, scale/anchor logic, and text overlay system are used by `stream_recv_cli` and the node's `START_DISPLAY` command.

See also: [`v4l2_view_cli.md`](v4l2_view_cli.md) for live camera feed display; [`stream_recv_cli.md`](stream_recv_cli.md) for network stream display.