andrewdolce

// The "optimal" velocity is the velocity needed to bring us to
// the target angle in a single physics step.
var optimalVelocity = targetAngle / dt;

// The "optimal" torque is the amount of torque needed this
// frame to achieve the "optimal" velocity.
var optimalTorque = ( optimalVelocity - angularVelocity ) / ( dt * inverseInertia );
var desiredTorqueSign = nonZeroSign( desiredTorque );

if ( desiredTorqueSign === nonZeroSign(optimalTorque) ) {

andrewdolce

// We're traveling in the same direction we want to go, so do we
// need to brake?
var brakeDist = 0;
var wantsBrake = false;
if ( result.ccw === angularVelocity > 0 ) {
  var brakeTime = -angularVelocity / ( brakeTorque * inverseInertia );
  brakeDist = brakeTime * angularVelocity * 0.5;
  wantsBrake = Math.abs(brakeDist) - Math.abs(targetAngle) > -0.01;
}

andrewdolce

if ( Math.abs(targetAngle) < 0.01 ) {
  var freeze = false;
  var freezeAccel;
  if ( angularVelocity > 0 ) {
    freezeAccel = maxCW * inverseInertia;
    freeze = angularVelocity + freezeAccel * dt < 0;
  } else {
    freezeAccel = maxCCW * inverseInertia;
    freeze = angularVelocity + freezeAccel * dt > 0;
  }

andrewdolce

// Target angle is closest via CW.
var brakeTorque, desiredTorque;
if ( targetAngle < 0 ) {
  if ( targetAngle < -Math.PI ) {
    console.warn( 'targetAngle < -π: targetAngle =', targetAngle );
  }

  desiredTorque = maxCW;
  brakeTorque = maxCCW;
  result.ccw = false;

andrewdolce

// Calculate normalized target vector to heading.
var globalHeading = input.faceHeading;
Vec2.setFromValues(
  targetDir,
  Math.cos( globalHeading ),
  Math.sin( globalHeading )
);

// Calculate angle between forward vector and target vector.
Mat2.multVec2( xf.rotation, LOCAL_FORWARD, forward );

andrewdolce

MLTS.prototype.calculateThrusterValues = function() {
    this.maxForward  = 0;
    this.maxBackward = 0;
    this.maxRight    = 0;
    this.maxLeft     = 0;
    this.maxCCW      = 0;
    this.maxCW       = 0;
 
    this.model.thrusters.forEach(function( thruster ) {
      if ( thruster.isAttached ) {

andrewdolce

// This is a JS component interface.
// It acts as the window to the physics layer. It also emits collision events
// that have been processed / generated by the CollisionEventDispatcher.
function Physics () {
  this.physicsId = null;
  // would store serializable physics properties like:
  // linear velocity
  // angular velocity
  // anything else needed for backing up physics state
};

andrewdolce

#!/bin/bash

MIN_LAG=25
MAX_LAG=50
(( LAG_RANGE = MAX_LAG - MIN_LAG ))

TIME=600 # total test time (in seconds)
INTERVAL=0.1 # time in between changes in latency (in seconds)
STEPS=6000 # TIME / INTERVAL

andrewdolce

$ sudo ipfw add 100 pipe 1 ip from 127.0.0.1 to 127.0.0.1 in
$ sudo ipfw add 100 allow ip from 127.0.0.1 to 127.0.0.1 out

andrewdolce

$ sudo ipfw pipe 1 config delay 100ms
$ sudo ipfw add 100 pipe 1 ip from 127.0.0.1 to 127.0.0.1