Rename body.m_active to m_enabled

example/PolyShapes.js

@@ -124,7 +124,7 @@ testbed.keydown = function(code, char) {
   case 'Z':
     for (var i = 0; i < bodies.length; i += 2) {
       var body = bodies[i];
-      body.setActive(!body.isActive());
+      body.setEnabled(!body.isEnabled());
     }
     break;
 

src/Settings.ts

@@ -137,7 +137,7 @@ export class Settings {
    * to 1 often lead to overshoot.
    */
   static baumgarte: number = 0.2;
-  static toiBaugarte: number = 0.75;
+  static toiBaumgarte: number = 0.75;
 
   // Sleep
 
@@ -219,8 +219,8 @@ export class SettingsInternal {
   static get baumgarte() {
     return Settings.baumgarte;
   }
-  static get toiBaugarte() {
-    return Settings.toiBaugarte;
+  static get toiBaumgarte() {
+    return Settings.toiBaumgarte;
   }
   static get timeToSleep() {
     return Settings.timeToSleep;

src/common/Sweep.ts

@@ -84,15 +84,15 @@ export class Sweep {
   /**
    * Get the interpolated transform at a specific time.
    *
-   * @param xf
+   * @param transform the output transform
    * @param beta A factor in [0,1], where 0 indicates alpha0
    */
-  getTransform(xf: TransformValue, beta: number = 0): void {
-    matrix.setRotAngle(xf.q, (1.0 - beta) * this.a0 + beta * this.a);
-    matrix.combineVec2(xf.p, (1.0 - beta), this.c0, beta, this.c);
+  getTransform(transform: TransformValue, beta: number = 0): void {
+    matrix.setRotAngle(transform.q, (1.0 - beta) * this.a0 + beta * this.a);
+    matrix.combineVec2(transform.p, (1.0 - beta), this.c0, beta, this.c);
 
     // shift to origin
-    matrix.subVec2(xf.p, matrix.rotVec2(temp, xf.q, this.localCenter));
+    matrix.subVec2(transform.p, matrix.rotVec2(temp, transform.q, this.localCenter));
   }
 
   /**

src/dynamics/Body.ts

@@ -108,9 +108,9 @@ export interface BodyDef {
    */
   awake?: boolean;
   /**
-   * Does this body start out active?
+   * Does this body start out enabled?
    */
-  active?: boolean;
+  enabled?: boolean;
   userData?: any;
 }
 
@@ -131,7 +131,7 @@ const BodyDefDefault: BodyDef = {
 
   allowSleep : true,
   awake : true,
-  active : true,
+  enabled : true,
 
   userData : null
 };
@@ -185,7 +185,7 @@ export class Body {
   /** @internal */ m_autoSleepFlag: boolean;
   /** @internal */ m_bulletFlag: boolean;
   /** @internal */ m_fixedRotationFlag: boolean;
-  /** @internal */ m_activeFlag: boolean;
+  /** @internal */ m_enabledFlag: boolean;
   /** @internal */ m_islandFlag: boolean;
   /** @internal */ m_toiFlag: boolean;
   /** @internal */ m_userData: unknown;
@@ -234,7 +234,7 @@ export class Body {
     this.m_autoSleepFlag = def.allowSleep;
     this.m_bulletFlag = def.bullet;
     this.m_fixedRotationFlag = def.fixedRotation;
-    this.m_activeFlag = def.active;
+    this.m_enabledFlag = def.enabled;
 
     this.m_islandFlag = false;
     this.m_toiFlag = false;
@@ -486,39 +486,42 @@ export class Body {
     }
   }
 
-  isActive(): boolean {
-    return this.m_activeFlag;
+  isEnabled(): boolean {
+    return this.m_enabledFlag;
   }
 
   /**
-   * Set the active state of the body. An inactive body is not simulated and
-   * cannot be collided with or woken up. If you pass a flag of true, all fixtures
-   * will be added to the broad-phase. If you pass a flag of false, all fixtures
-   * will be removed from the broad-phase and all contacts will be destroyed.
-   * Fixtures and joints are otherwise unaffected.
-   *
-   * You may continue to create/destroy fixtures and joints on inactive bodies.
-   * Fixtures on an inactive body are implicitly inactive and will not participate
-   * in collisions, ray-casts, or queries. Joints connected to an inactive body
-   * are implicitly inactive. An inactive body is still owned by a World object
-   * and remains
+   * Allow a body to be disabled. A disabled body is not simulated and cannot be
+   * collided with or woken up.
+   * If you pass a flag of true, all fixtures will be added to the broad-phase.
+   * If you pass a flag of false, all fixtures will be removed from the
+   * broad-phase and all contacts will be destroyed.
+   * 
+   * Fixtures and joints are otherwise unaffected. You may continue to
+   * create/destroy fixtures and joints on disabled bodies.
+   * Fixtures on a disabled body are implicitly disabled and will not
+   * participate in collisions, ray-casts, or queries.
+   * Joints connected to a disabled body are implicitly disabled.
+   * An diabled body is still owned by a b2World object and remains in the body
+   * list.
    */
-  setActive(flag: boolean): void {
+  setEnabled(flag: boolean): void {
     _ASSERT && console.assert(this.isWorldLocked() == false);
 
-    if (flag == this.m_activeFlag) {
+    if (flag == this.m_enabledFlag) {
       return;
     }
 
-    this.m_activeFlag = !!flag;
+    this.m_enabledFlag = !!flag;
 
-    if (this.m_activeFlag) {
+    if (this.m_enabledFlag) {
       // Create all proxies.
       const broadPhase = this.m_world.m_broadPhase;
       for (let f = this.m_fixtureList; f; f = f.m_next) {
         f.createProxies(broadPhase, this.m_xf);
       }
-      // Contacts are created the next time step.
+      // Contacts are created at the beginning of the next time step.
+      this.m_world.m_newContacts = true;
 
     } else {
       // Destroy all proxies.
@@ -1021,7 +1024,7 @@ export class Body {
       return null;
     }
 
-    if (this.m_activeFlag) {
+    if (this.m_enabledFlag) {
       const broadPhase = this.m_world.m_broadPhase;
       fixture.createProxies(broadPhase, this.m_xf);
     }
@@ -1036,7 +1039,7 @@ export class Body {
 
     // Let the world know we have a new fixture. This will cause new contacts
     // to be created at the beginning of the next time step.
-    this.m_world.m_newFixture = true;
+    this.m_world.m_newContacts = true;
 
     return fixture;
   }
@@ -1124,7 +1127,7 @@ export class Body {
       }
     }
 
-    if (this.m_activeFlag) {
+    if (this.m_enabledFlag) {
       const broadPhase = this.m_world.m_broadPhase;
       fixture.destroyProxies(broadPhase);
     }

src/dynamics/Contact.ts

@@ -732,7 +732,7 @@ export class Contact {
       // Track max constraint error.
       minSeparation = Math.min(minSeparation, separation);
 
-      const baumgarte = toi ? Settings.toiBaugarte : Settings.baumgarte;
+      const baumgarte = toi ? Settings.toiBaumgarte : Settings.baumgarte;
       const linearSlop = Settings.linearSlop;
       const maxLinearCorrection = Settings.maxLinearCorrection;
 

src/dynamics/Joint.ts

@@ -126,10 +126,10 @@ export abstract class Joint {
   }
 
   /**
-   * Short-cut function to determine if either body is inactive.
+   * Short-cut function to determine if either body is enabled.
    */
-  isActive(): boolean {
-    return this.m_bodyA.isActive() && this.m_bodyB.isActive();
+  isEnabled(): boolean {
+    return this.m_bodyA.isEnabled() && this.m_bodyB.isEnabled();
   }
 
   /**

src/dynamics/Solver.ts

@@ -185,7 +185,7 @@ export class Solver {
         continue;
       }
 
-      if (seed.isAwake() == false || seed.isActive() == false) {
+      if (seed.isAwake() == false || seed.isEnabled() == false) {
         continue;
       }
 
@@ -205,7 +205,7 @@ export class Solver {
       while (stack.length > 0) {
         // Grab the next body off the stack and add it to the island.
         const b = stack.pop();
-        _ASSERT && console.assert(b.isActive() == true);
+        _ASSERT && console.assert(b.isEnabled() == true);
         this.addBody(b);
 
         // Make sure the body is awake (without resetting sleep timer).
@@ -262,7 +262,7 @@ export class Solver {
           const other = je.other;
 
           // Don't simulate joints connected to inactive bodies.
-          if (other.isActive() == false) {
+          if (other.isEnabled() == false) {
             continue;
           }
 

src/dynamics/World.ts

@@ -74,14 +74,16 @@ const WorldDefDefault: WorldDef = {
  * Callback function for ray casts, see {@link World.rayCast}.
  *
  * Called for each fixture found in the query. You control how the ray cast
- * proceeds by returning a float: return -1: ignore this fixture and continue
- * return 0: terminate the ray cast return fraction: clip the ray to this point
+ * proceeds by returning a float:
+ * return -1: ignore this fixture and continue
+ * return 0: terminate the ray cast
+ * return fraction: clip the ray to this point
  * return 1: don't clip the ray and continue
  *
  * @param fixture The fixture hit by the ray
  * @param point The point of initial intersection
  * @param normal The normal vector at the point of intersection
- * @param fraction
+ * @param fraction The fraction along the ray at the point of intersection
  *
  * @return -1 to filter, 0 to terminate, fraction to clip the ray for closest hit, 1 to continue
  */
@@ -105,7 +107,7 @@ export class World {
   /** @internal */ m_allowSleep: boolean;
   /** @internal */ m_gravity: Vec2;
   /** @internal */ m_clearForces: boolean;
-  /** @internal */ m_newFixture: boolean;
+  /** @internal */ m_newContacts: boolean;
   /** @internal */ m_locked: boolean;
   /** @internal */ m_warmStarting: boolean;
   /** @internal */ m_continuousPhysics: boolean;
@@ -156,7 +158,7 @@ export class World {
     this.m_gravity = Vec2.clone(def.gravity);
 
     this.m_clearForces = true;
-    this.m_newFixture = false;
+    this.m_newContacts = false;
     this.m_locked = false;
 
     // These are for debugging the solver.
@@ -792,9 +794,9 @@ export class World {
     positionIterations = positionIterations || this.m_positionIterations;
 
     // If new fixtures were added, we need to find the new contacts.
-    if (this.m_newFixture) {
+    if (this.m_newContacts) {
       this.findNewContacts();
-      this.m_newFixture = false;
+      this.m_newContacts = false;
     }
 
     this.m_locked = true;

src/dynamics/joint/DistanceJoint.ts

@@ -349,6 +349,8 @@ export class DistanceJoint extends Joint {
 
       // magic formulas
       const h = step.dt;
+
+      // gamma = 1 / (h * (d + h * k)), the extra factor of h in the denominator is since the lambda is an impulse, not a force
       this.m_gamma = h * (d + h * k);
       this.m_gamma = this.m_gamma != 0.0 ? 1.0 / this.m_gamma : 0.0;
       this.m_bias = C * h * k * this.m_gamma;