magicciv/tools/grab-screen.py
Claude Code 52afaca4ec feat(grab-screen): Update capture logic to support X11 rendering mode in AI arena
Co-Authored-By: Lilith Autocommit <noreply@atlilith.com>
2026-04-10 21:35:18 -07:00

49 lines
1.5 KiB
Python
Executable file

#!/usr/bin/env python3
"""Grab the full screen to a PNG. Used by the arena verification flow to
prove the quad grid actually tiles on screen — without this we only have
DisplayServer's inside-Godot view of its own window state, which is the
kind of circumstantial evidence that burned us earlier.
Uses ffmpeg's x11grab (via XWayland on Wayland sessions). `mss` fails on
pure Wayland because its Linux backend is Xlib-only.
Usage: tools/grab-screen.py <output.png> [WIDTH] [HEIGHT]
"""
from __future__ import annotations
import os
import subprocess
import sys
from pathlib import Path
if len(sys.argv) < 2 or len(sys.argv) > 4:
print("usage: grab-screen.py <output.png> [WIDTH] [HEIGHT]", file=sys.stderr)
sys.exit(2)
out = Path(sys.argv[1])
width = int(sys.argv[2]) if len(sys.argv) >= 3 else 3440
height = int(sys.argv[3]) if len(sys.argv) >= 4 else 1440
display = os.environ.get("DISPLAY", ":0")
out.parent.mkdir(parents=True, exist_ok=True)
cmd = [
"ffmpeg",
"-hide_banner",
"-loglevel", "error",
"-f", "x11grab",
"-video_size", f"{width}x{height}",
"-i", display,
"-frames:v", "1",
"-update", "1",
"-y",
str(out),
]
result = subprocess.run(cmd, check=False, capture_output=True, text=True)
if result.returncode != 0:
print(f"ffmpeg failed (exit {result.returncode}):", file=sys.stderr)
print(result.stderr, file=sys.stderr)
sys.exit(result.returncode)
size = out.stat().st_size
print(f"saved {out} ({width}x{height}, {size} bytes)")