G-Rebels v0.66 extended telemetry GUESSWORK

/* Disclaimer: I've no motion rig so this is guess work at best.
* I'm more looking into telemetry for a home cockpit - that means hard targeting data,
* enemy position, scan status, loadout, stuff like that. Nothing of this is here :/
*
* This is based on the early access 0.66 of G-Rebels and uses the
* *extended* Telemetry output via UDP of the ingame options and nothing else.
*
* AFTER this was guessed https://reakktor.com/htm/gr_telemetry.htm was released
* from the official developers - that also gets updated.
*
* This is a demo snippet for NodeJS - just run it with 'node' and the game starts
* blabbing once the extended telemetry is enabled in the game.
*
* Should be enough to get you started 🤓
*
* -- bekopharm
* */
const dgram = require('dgram');
const server = dgram.createSocket('udp4');

const PORT = 33001;
const HOST = '127.0.0.1';

// Verified fixed offsets for the G-Rebels 236-byte telemetry packet
const TEXT1_START = 0;       // "api"
const TEXT2_START = 8;       // "G-Rebels"
const TEXT3_START = 58;      // "X-Type" (Vehicle blueprint class name)
const TEXT4_START = 108;     // "BP_SECTOR_C_..." (World sector or asset ID??)
const TELEMETRY_START = 160; // Start of the Float32 flight dynamics values

// Gameplay telemetry zone at the end of the packet
const LASER_SHOTS_START = 212;  // Primary weapon count (Int32)
const MISSILE_SHOTS_START = 216; // Missiles fired counter (Int32)
const ENEMY_HITS_START = 220;    // Incoming damage hits counter from enemies (Int32)
const IMPACT_START = 224;        // Wall/Environment collision counter (Int32)
const SHIELD_IMP_START = 232;    // Final Float: Shield impact absorption impulse?? (Delta)

// Change tracking storage for event triggers
let lastLaserCount = null;
let lastMissileCount = null;
let lastHitCount = null;
let lastImpactCount = null;

function parseText(buffer, startOffset, maxLength) {
    const segment = buffer.subarray(startOffset, startOffset + maxLength);
    const nullIndex = segment.indexOf(0);
    return nullIndex === -1
        ? segment.toString('ascii')
        : segment.subarray(0, nullIndex).toString('ascii');
}

server.on('message', (msg, rinfo) => {
    if (msg.length !== 236) return;

    // 1. Parse text fields
    const text3 = parseText(msg, TEXT3_START, 50);
    const text4 = parseText(msg, TEXT4_START, 52);

    // 2. Read motion dynamics (Float32 Little Endian)
    const pitch = msg.readFloatLE(TELEMETRY_START + 0);
    const roll  = msg.readFloatLE(TELEMETRY_START + 4);
    const rawYaw = msg.readFloatLE(TELEMETRY_START + 8);

    // IN-GAME COMPASS SYNC: Map raw Unreal Engine Yaw to 0-360° HUD heading
    let headingDeg = rawYaw + 86.05; // or 90? hard to tell
    if (headingDeg >= 360) headingDeg -= 360;
    if (headingDeg < 0) headingDeg += 360;

    // Linear acceleration (Float32 LE)
    const accLongitudinal = msg.readFloatLE(TELEMETRY_START + 16); // Surge acceleration
    const accLateral      = msg.readFloatLE(TELEMETRY_START + 20); // Sway acceleration
    const accVertical     = msg.readFloatLE(TELEMETRY_START + 24); // Heave acceleration

    // Thrust input controls (Float32 LE, -1..+1)
    const thrustForward = msg.readFloatLE(TELEMETRY_START + 40); // Forward/reverse throttle
    const thrustVertical = msg.readFloatLE(TELEMETRY_START + 44); // Vertical thrust
    const thrustLateral = msg.readFloatLE(TELEMETRY_START + 48); // Lateral thrust

    // Translate Unreal Engine Units (cm/s) directly into km/h
    const speedCmS  = msg.readFloatLE(TELEMETRY_START + 28);
    const speedKmh  = (speedCmS / 100) * 3.6;

    // Local cockpit translation/strafe forces (G-forces? little hight…)
    const gSwayLocal  = msg.readFloatLE(TELEMETRY_START + 32); // Left (-) / Right (+)
    const gHeaveLocal = msg.readFloatLE(TELEMETRY_START + 36); // Up (-) / Down (+)

    // 3. Read gameplay event counters
    const currentLaserCount = msg.readInt32LE(LASER_SHOTS_START);
    const currentMissileCount = msg.readInt32LE(MISSILE_SHOTS_START);
    const currentHitCount = msg.readInt32LE(ENEMY_HITS_START);
    const currentImpactCount = msg.readInt32LE(IMPACT_START);
    const hitStrength = msg.readFloatLE(228);
    const shieldImpulse = msg.readFloatLE(SHIELD_IMP_START);

    // Calculate event triggers for tactile hardware/shakers
    const laserFired = (lastLaserCount !== null && currentLaserCount > lastLaserCount);
    const missileFired = (lastMissileCount !== null && currentMissileCount > lastMissileCount);
    const hitSustained = (lastHitCount !== null && currentHitCount > lastHitCount);
    const wallCollision = (lastImpactCount !== null && currentImpactCount > lastImpactCount);

    // Store current state for next tick comparisons
    lastLaserCount = currentLaserCount;
    lastMissileCount = currentMissileCount;
    lastHitCount = currentHitCount;
    lastImpactCount = currentImpactCount;

    // Output formatted live console dump
    console.clear();
    console.log(`[G-Rebels Telemetry | Motion Rig Parser]`);
    console.log(`==================================================`);
    console.log(`Vehicle Class:  "${text3}"`);
    console.log(`World Sector:   "${text4}"`);
    console.log(`--------------------------------------------------`);
    console.log(`Orientation & Navigation (HUD Synced):`);
    console.log(`  Pitch (Attitude):     ${pitch.toFixed(2)}°`);
    console.log(`  Roll (Bank):          ${roll.toFixed(2)}°`);
    console.log(`  Compass (Heading):    ${headingDeg.toFixed(1)}°`);
    console.log(`--------------------------------------------------`);
    console.log(`Rig Dynamics (Direct Actuator Forces):`);
    console.log(`  Flight Speed:         ${speedKmh.toFixed(0)} km/h`);
    console.log(`  Acceleration:     Longitudinal: ${accLongitudinal.toFixed(2)} | Lateral: ${accLateral.toFixed(2)} | Vertical: ${accVertical.toFixed(2)}`);
    console.log(`  Cockpit Strafe (G):   Sway (Lateral): ${gSwayLocal.toFixed(3)} ??`);
    console.log(`                        Heave (Vert):   ${gHeaveLocal.toFixed(3)} ??`);
    console.log(`  Thrust Inputs:        Forward: ${thrustForward.toFixed(2)} | Vertical: ${thrustVertical.toFixed(2)} | Lateral: ${thrustLateral.toFixed(2)}`);
    console.log(`--------------------------------------------------`);
    console.log(`Gameplay Counters & Game State:`);
    console.log(`  Laser / Missile Fire: ${currentLaserCount} / ${currentMissileCount}`);
    console.log(`  Enemy Hits / Crashes: ${currentHitCount} / ${currentImpactCount}`);
    console.log(`  Hit Strength (Δ) ???:    ${hitStrength.toFixed(4)}`);
    console.log(`  Shield Impulse (Δ) ??:   ${shieldImpulse.toFixed(4)}`);
    console.log(`==================================================`);

    // Haptic/Motion triggers ready to map to hardware profiles
    if (laserFired)   console.log(`[FEEDBACK] RECOIL: Laser gun fired!`);
    if (missileFired)  console.log(`[FEEDBACK] RECOIL: Missile launched!`);
    if (hitSustained) console.log(`[FEEDBACK] DAMAGE: Vehicle hit by enemy!`);
    if (wallCollision)   console.log(`[FEEDBACK] IMPACT: Vehicle crashed into obstacle!`);
});

server.on('listening', () => {
    const address = server.address();
    console.log(`G-Rebels UDP Parser actively listening on ${address.address}:${address.port}`);
});

server.bind(PORT, HOST);