monsterplex/src/config.js

// Every spatial (pixel) constant in this file and in src/data/levels/*.js is
// multiplied by WORLD_SCALE, so the whole game - canvas, physics bodies,
// terrain, UI - resizes together. Change this one number to rescale it again.
export const WORLD_SCALE = 2; // 960x540 base design -> 1920x1080

export const GAME_WIDTH = 960 * WORLD_SCALE;
export const GAME_HEIGHT = 540 * WORLD_SCALE;

// Set true to show live g-force / debug readouts during PlayScene.
export const DEBUG = false;

export const STORAGE_KEY = 'monsterplex.progress.v1';

// Matter runs Phaser's default fixed 60Hz step.
export const PHYSICS_TIMESTEP_SECONDS = 1 / 60;

export const BUS = {
  chassisWidth: 170 * WORLD_SCALE,
  chassisHeight: 64 * WORLD_SCALE,

  // Measured directly from assets/sprites/bus_chassis.png's baked-in wheel
  // wells (it's a real photo bus - long rear overhang, short front hood, so
  // the axles are NOT symmetric around the chassis center). Offsets are from
  // the chassis center; re-measure these if bus_chassis.png is replaced.
  wheelRadius: 17 * WORLD_SCALE,
  rearWheelOffsetX: -35 * WORLD_SCALE,
  frontWheelOffsetX: 64 * WORLD_SCALE,
  // Where the wheel's CENTER rests at equilibrium. Raised from the
  // wheel-well-measured 22 to 34 to lift the chassis and drop the tires
  // further down for a bouncier stance - this now visibly departs from
  // bus_chassis.png's painted wheel wells (a gap opens above the tire),
  // a deliberate look/feel tradeoff rather than a measurement.
  wheelRestOffsetY: 34 * WORLD_SCALE,
  // Horizontal spread between the two suspension links each wheel hangs
  // from (a "wishbone") - a single point-to-point constraint can't resist
  // sideways drift at all (it's radially symmetric), so each wheel is held
  // by two constraints spread by this much, which resists side-to-side
  // wander while still allowing the wheel to compress/extend vertically.
  axleSpread: 6 * WORLD_SCALE,

  maxSeats: 5,

  // The invisible box kids ride in, local to the chassis (0,0 = chassis
  // center, y down): solid floor + left/right walls, but deliberately no
  // ceiling fixture at all - see Bus.js's _buildCompartment. A kid whose
  // own local Y (rotation-corrected relative to the chassis) rises above
  // compartmentTopY has nothing left to collide with and is airborne; the
  // same check runs both directions each tick (see KidManager), so falling
  // back below it while inside compartmentHalfWidth re-contains the kid.
  // Tune by playtesting - not physically derived.
  compartmentHalfWidth: 75 * WORLD_SCALE,
  compartmentWallThickness: 10 * WORLD_SCALE,
  compartmentFloorThickness: 10 * WORLD_SCALE,
  compartmentFloorY: 12 * WORLD_SCALE,
  compartmentTopY: -60 * WORLD_SCALE,

  // Density/friction/stiffness/damping are dimensionless ratios, not pixel
  // distances - they don't scale with WORLD_SCALE.
  chassisDensity: 0.0015,
  chassisFriction: 0.4,
  chassisFrictionAir: 0.01,

  wheelDensity: 0.004,
  wheelFriction: 0.9,
  wheelFrictionStatic: 1.4,
  // Lowered a lot from the original 0.02 - that was quietly eating most of
  // the wheel's spin-up each second (it's a per-tick multiplicative decay,
  // so 0.02 was burning off roughly a third of angular velocity per second)
  // and was the main reason the bus felt sluggish rather than Trials-fast.
  wheelFrictionAir: 0.008,
  // Some bounce on landing, not just suspension absorbing everything.
  wheelRestitution: 0.45,

  // Softer and less damped than before - more travel, and lets it actually
  // oscillate (bounce) instead of settling immediately - "more shocks."
  suspensionStiffness: 0.35,
  suspensionDamping: 0.035,
  // How far the wheel can move up/down from wheelRestOffsetY. This will
  // visibly pop the wheel outside its wheel well on a hard landing - that's
  // the tradeoff for real suspension travel/bounce instead of a stiff ride.
  suspensionTravel: 30 * WORLD_SCALE,

  // Angular velocities/torque steps are rotational (radians), not linear
  // pixel distances, so they're left unscaled - wheel radius already scaled,
  // so linear surface speed (angularVelocity * radius) scales automatically.
  // Pushed way up from the original values for Trials/Snuggle-Truck-style
  // speed - the old numbers made the bus crawl.
  maxWheelAngularVelocity: 5,
  driveTorque: 0.6,
  brakeTorque: 0.4,
  maxBrakeAngularVelocity: 3.5,

  // Measured via headless testing: spinning the wheel faster alone barely
  // moved the chassis - past a point the wheel just slips (friction force
  // is capped by frictionCoefficient * normalForce regardless of how fast
  // the wheel spins beyond matching ground speed), so throttle applies a
  // direct force to the chassis itself, along its current facing/tilt, on
  // top of the wheel spin. This is the standard fix in arcade 2D driving
  // games for exactly this problem. Expressed as target acceleration
  // (Bus.js computes force = chassis mass * this) rather than a raw force,
  // so it stays correct if chassisDensity/size ever changes - tune these
  // to change top speed feel.
  // Cut by ~60% (0.011 -> 0.0045) for a much longer runway to top speed.
  // Note this also lowers the top speed itself, not just the time to reach
  // it - top speed is where this force balances chassisFrictionAir drag, so
  // a smaller force settles at a lower equilibrium speed too.
  driveAcceleration: 0.0045,
  brakeAcceleration: 0.007,

  // Cut by more than half (both the cap and the per-tick torque step) for a
  // much slower, more gradual lean - easier to fine-tune mid-air at the
  // cost of snappiness.
  maxLeanAngularVelocity: 0.06,
  leanTorqueStep: 0.004,
};

// Kid ejection is no longer impact-triggered (see KidManager/Bus's
// compartment box) - GFORCE now only drives the DEBUG g-force readout in
// PlayScene, kept because it's still a useful "how hard did that landing
// hit" diagnostic on its own.
export const GFORCE = {
  // Scaled with WORLD_SCALE so "meters" keeps the same real-world meaning
  // relative to the bus.
  pixelsPerMeter: 50 * WORLD_SCALE,
  gracePeriodMs: 500,
};

export const KID = {
  radius: 14 * WORLD_SCALE,
  density: 0.001,
  friction: 0.6,
  // While outside the compartment (past the open top - see
  // BUS.compartmentTopY), a kid ignores the world's real gravity entirely
  // and KidManager applies this fraction of it instead (see
  // KidManager._onBeforeUpdate) - horizontal velocity is untouched either
  // way (this game's gravity is purely vertical), so a lighter fall is all
  // it takes for a kid to hang in the air and arc much further than the
  // bus does, Snuggle-Truck style. Primary tuning knob for "how floaty,"
  // not physically derived.
  ejectedGravityScale: 0.35,
};

export const CAMERA = {
  lerpX: 0.1,
  lerpY: 0.1,
  // Horizontal position is speed-driven (see CameraRig.update - it steers
  // via followOffset.x) rather than a dead zone, so this is kept tiny
  // rather than removed, just to dodge exact-equality edge cases in
  // Phaser's deadzone math. Vertical still uses a real dead zone below.
  deadzoneWidth: 2 * WORLD_SCALE,
  deadzoneHeight: 140 * WORLD_SCALE,

  // Where the bus sits on screen, as a fraction of screen width from the
  // left edge - primary tuning knobs, not physically derived, tune by
  // playtesting. restScreenFraction leaves enough room for the chassis
  // (half its width is ~0.09 of the screen) not to clip off the left edge
  // while still reading as "almost touching."
  restScreenFraction: 0.1,
  maxSpeedScreenFraction: 1 / 3,
  // Horizontal chassis speed (px/s) at which framing reaches
  // maxSpeedScreenFraction; clamped beyond it. There's no hard speed cap in
  // the drive physics (chassisFrictionAir just balances driveAcceleration
  // out asymptotically), so this is a starting estimate - tune by
  // playtesting alongside the fractions above.
  lookaheadMaxSpeed: 110 * WORLD_SCALE,
};

export const TERRAIN_DEPTH = 400 * WORLD_SCALE;