pause on import

deploy

@@ -15,4 +15,4 @@ elif [[ $(hostname) == "lentilz" ]]; then
 fi
 
 echo >&2
-echo >&2 "Deployed to https://laddhoffman.com/gravity/"
+echo >&2 "Deployed to https://gravity.laddhoffman.com"

object.js

@@ -31,6 +31,9 @@ export class MassObject {
   forces = []; // [{x, y}]
   history = [];
   alive = true;
+  kineticEnergy = 0;
+  workDoneByPointer = 0;
+  workDoneByForces = 0;
 
   currentPosition = undefined;
   currentAcceleration = undefined;
@@ -56,7 +59,8 @@ export class MassObject {
       color: this.color,
       timeCreated: this.timeCreated,
       alive: this.alive,
-      // TODO: optional export history
+      workDoneByPointer: this.workDoneByPointer,
+      workDoneByForces: this.workDoneByForces,
     };
   }
 
@@ -69,8 +73,9 @@ export class MassObject {
     this.color = obj.color;
     this.timeCreated = obj.timeCreated;
     this.alive = obj.alive;
-    // TODO: optional import history
     this.history = [];
+    this.workDoneByPointer = obj.workDoneByPointer;
+    this.workDoneByForces = obj.workDoneByForces;
   }
 
   get age() {

panning.js

@@ -30,13 +30,12 @@ export class Panning {
   toJSON() {
     return {
       velocity: this.velocity,
-      paused: this.paused,
     };
   }
 
-  fromJSON({velocity, paused}) {
+  fromJSON({velocity}) {
     this.velocity = copy(velocity);
-    this.paused = paused;
+    this.paused = true;
   }
 
   handlePointerDown({x, y}) {

simulator.js

@@ -141,6 +141,7 @@ export class Sim {
   }
 
   fromJSON(state) {
+    this.pause();
     this.system.fromJSON(state.system);
     this.panning.fromJSON(state.panning);
     this.display.fromJSON(state.display);

sync

@@ -16,9 +16,9 @@ do_rsync() {
 }
 
 do_rsync ~/code/gravity-dev/ lentilz:code/gravity-dev/
-do_rsync lentilz:code/gravity-dev/ ~/code/gravity-dev/ 
+# do_rsync lentilz:code/gravity-dev/ ~/code/gravity-dev/ 
 
 git status
 
 echo >&2
-echo >&2 "Synced with https://laddhoffman.com/gravity-dev/"
+echo >&2 "Synced with https://gravity.dev.laddhoffman.com"

system.js

@@ -171,8 +171,8 @@ export class System {
           const delta = sub(obj.currentPosition, obj.position);
           const netForce = mult(obj.acceleration, obj.mass);
           const work = dot(netForce, delta);
-          console.log('work', work);
           obj.position = obj.currentPosition;
+          obj.workDoneByPointer += work;
         }
 
         // Append to object history
@@ -408,11 +408,20 @@ export class System {
         // Equal and opposite forces
         A.forces.push({x: Fx, y: Fy});
         B.forces.push({x: -Fx, y: -Fy});
+        if (A.currentPosition && B.currentPosition) {
+          A.workDoneByForces += dot({x: Fx, y: Fy}, sub(A.position, A.currentPosition));
+          B.workDoneByForces += dot({x: Fx, y: Fy}, sub(B.position, B.currentPosition));
+        }
       }, {alive: true, startWith: i + 1});
     });
-    // Also compute acceleration
+
+    // Additional computations
     this.forEachObject(obj => {
+      // Acceleration
       obj.acceleration = obj.getAcceleration();
+
+      // Kinetic Energy
+      obj.kineticEnergy = obj.mass * square(obj.velocity) / 2;
     });
   }
 

tool/objects.js

@@ -1,6 +1,5 @@
 import {hide, show} from '../helper.js';
 import {Tool} from '../tool.js';
-import {add, magnitude, sub} from '../vector.js';
 
 export class ObjectsTool extends Tool {
   objects = [];
@@ -58,17 +57,22 @@ export class ObjectsTool extends Tool {
       obj.objectsToolEl = objectEl;
       const {r, g, b} = obj.color;
       // Distance from center of screen
-      const distance = magnitude(sub(obj.position, add(this.sim.display.viewOrigin, {
-        x: this.sim.display.width / 2,
-        y: this.sim.display.height / 2,
-      })));
-      objectEl.innerHTML = `
-        <span style="background-color: rgb(${r},${g},${b});">` +
-        '&nbsp;&nbsp;</span>' +
-        `${obj.mass.toPrecision(3)} ` +
-        `${distance.toPrecision(3)}`;
+      // const distance = magnitude(sub(obj.position, add(this.sim.display.viewOrigin, {
+      // x: this.sim.display.width / 2,
+      // y: this.sim.display.height / 2,
+      // })));
+      objectEl.innerHTML =
+        `<span style="background-color: rgb(${r},${g},${b});">&nbsp;&nbsp;</span>` +
+        `E<sub>k</sub>: ${obj.kineticEnergy.toExponential(1)}` +
+        `<br>&nbsp;&nbsp;W<sub>p</sub>: ${obj.workDoneByPointer.toExponential(1)}` +
+        `<br>&nbsp;&nbsp;W<sub>f</sub>: ${obj.workDoneByForces.toExponential(1)}`;
+
+      // `${obj.mass.toPrecision(3)} ` +
+      // `${distance.toPrecision(3)}`;
+
       // `${magnitude(obj.velocity).toExponential(0)} ` +
       // `${-degrees(direction(obj.velocity)).toFixed(0)}°`;
+
       if (!obj.hidden) {
         show({
           items: this.objects,

tool/state.js

@@ -56,7 +56,6 @@ export class StateTool extends Tool {
         throw new Error('state query parameter does not match digest query parameter');
       }
       // Tools in this system can be very powerful
-      this.sim.pause();
       this.sim.fromJSON(state);
     }
   }
@@ -99,7 +98,6 @@ export class StateTool extends Tool {
     load.addEventListener('click', (e) => {
       e.preventDefault();
       // Tools in this system can wield great power
-      this.sim.pause();
       this.sim.fromJSON(state);
     });