Merge pull request #61 from pmndrs/wakeup-force-impulse

Wakeup a body if a force is applied to it

examples/impulses.html

@@ -30,83 +30,87 @@
         const world = setupWorld(demo)
 
         const shape = new CANNON.Sphere(radius)
-        const body = new CANNON.Body({
-          mass,
-          position: new CANNON.Vec3(0, 1, 0),
-        })
+        const body = new CANNON.Body({ mass })
         body.addShape(shape)
         body.linearDamping = damping
         body.angularDamping = damping
         world.addBody(body)
         demo.addVisual(body)
 
-        // Add an impulse to the center
-        const worldPoint = new CANNON.Vec3(0, 0, 0)
         const impulse = new CANNON.Vec3(-strength * dt, 0, 0)
-        body.applyImpulse(impulse, worldPoint)
+        body.applyImpulse(impulse)
       })
 
       // Add impulse to the top of the sphere
       demo.addScene('Top impulse', () => {
         const world = setupWorld(demo)
 
         const shape = new CANNON.Sphere(radius)
-        const body = new CANNON.Body({
-          mass,
-          position: new CANNON.Vec3(0, 1, 0),
-        })
+        const body = new CANNON.Body({ mass })
         body.addShape(shape)
         body.linearDamping = damping
         body.angularDamping = damping
         world.addBody(body)
         demo.addVisual(body)
 
-        // Add an impulse to the center
-        const worldPoint = new CANNON.Vec3(0, radius, 0)
+        // The top of the sphere, relative to the sphere center
+        const topPoint = new CANNON.Vec3(0, radius / 2, 0)
         const impulse = new CANNON.Vec3(-strength * dt, 0, 0)
-        body.applyImpulse(impulse, worldPoint)
+        body.applyImpulse(impulse, topPoint)
       })
 
       // Add force to the body center
       demo.addScene('Center force', () => {
         const world = setupWorld(demo)
 
         const shape = new CANNON.Sphere(radius)
-        const body = new CANNON.Body({
-          mass,
-          position: new CANNON.Vec3(0, 1, 0),
-        })
+        const body = new CANNON.Body({ mass })
         body.addShape(shape)
         body.linearDamping = damping
         body.angularDamping = damping
         world.addBody(body)
         demo.addVisual(body)
 
-        // Add an force to the center
-        const worldPoint = new CANNON.Vec3(0, 0, 0)
         const force = new CANNON.Vec3(-strength, 0, 0)
-        body.applyForce(force, worldPoint)
+        body.applyForce(force)
       })
 
       // Add force to the top of the sphere
       demo.addScene('Top force', () => {
         const world = setupWorld(demo)
 
         const shape = new CANNON.Sphere(radius)
-        const body = new CANNON.Body({
-          mass,
-          position: new CANNON.Vec3(0, 1, 0),
-        })
+        const body = new CANNON.Body({ mass })
         body.addShape(shape)
         body.linearDamping = damping
         body.angularDamping = damping
         world.addBody(body)
         demo.addVisual(body)
 
-        // Add an force to the center
-        const worldPoint = new CANNON.Vec3(0, radius, 0)
+        // The top of the sphere, relative to the sphere center
+        const topPoint = new CANNON.Vec3(0, radius / 2, 0)
         const force = new CANNON.Vec3(-strength, 0, 0)
-        body.applyForce(force, worldPoint)
+        body.applyForce(force, topPoint)
+      })
+
+      // Apply a force in the local space
+      demo.addScene('Local force', () => {
+        const world = setupWorld(demo)
+
+        const shape = new CANNON.Sphere(radius)
+        const body = new CANNON.Body({ mass })
+        body.addShape(shape)
+        body.linearDamping = damping
+        body.angularDamping = damping
+        body.quaternion.setFromEuler(0, 0, Math.PI)
+        world.addBody(body)
+        demo.addVisual(body)
+
+        // it's the top point, but since the sphere is rotated
+        // by 180 degrees, it is the bottom point to the right
+        const topPoint = new CANNON.Vec3(0, radius / 2, 0)
+        const force = new CANNON.Vec3(-strength, 0, 0)
+        body.applyLocalForce(force, topPoint)
       })
 
       demo.start()

examples/sleep.html

@@ -49,7 +49,7 @@
       })
 
       // Wake up demo
-      demo.addScene('Wake up', () => {
+      demo.addScene('Wake up when hit', () => {
         const world = setupWorld(demo)
 
         // Create sphere
@@ -89,6 +89,41 @@
         })
       })
 
+      // Wake up demo
+      demo.addScene('Wake up with impulse', () => {
+        const world = setupWorld(demo)
+
+        // Create sphere
+        const size = 2
+        const sphere = new CANNON.Sphere(size)
+        const sphereBody = new CANNON.Body({ mass: 1 })
+        sphereBody.addShape(sphere)
+        sphereBody.position.set(0, size, 0)
+        world.addBody(sphereBody)
+        demo.addVisual(sphereBody)
+
+        // Force it to sleep
+        sphereBody.sleep()
+
+        // Allow sleeping
+        world.allowSleep = true
+        sphereBody.allowSleep = true
+
+        // Sleep parameters
+        sphereBody.sleepSpeedLimit = 0.5
+        sphereBody.sleepTimeLimit = 1
+
+        // Apply an impulse after a bit
+        setTimeout(() => {
+          sphereBody.applyLocalImpulse(new CANNON.Vec3(5, 0, 0), new CANNON.Vec3())
+        }, 1000)
+
+        // The body wakes up when it gets a new contact
+        sphereBody.addEventListener('wakeup', (event) => {
+          console.log('The sphere woke up!')
+        })
+      })
+
       demo.start()
 
       function setupWorld(demo) {

readme.md

@@ -11,6 +11,7 @@ These minor changes and improvements were also made:
 - The `Cylinder` is now oriented on the Y axis. [#30](https://github.com/pmndrs/cannon-es/pull/30)
 - The `type` property of the `Cylinder` is now equal to `Shape.types.CYLINDER`. [#59](https://github.com/pmndrs/cannon-es/pull/59)
 - `Body.applyImpulse()` and `Body.applyForce()` are now relative to the center of the body instead of the center of the world [86b0444](https://github.com/schteppe/cannon.js/commit/86b0444c93356aeaa25dd1af795fa162574c6f4b)
+- Sleeping bodies now wake up if a force or an impulse is applied to them [#61](https://github.com/pmndrs/cannon-es/pull/61)
 - Added a property `World.hasActiveBodies: boolean` which will be false when all physics bodies are sleeping. This allows for invalidating frames when physics aren't active for increased performance.
 - Deprecated properties and methods have been removed.
 - The [original cannon.js debugger](https://github.com/schteppe/cannon.js/blob/master/tools/threejs/CannonDebugRenderer.js), which shows the wireframes of each body, has been moved to its own repo [cannon-es-debugger](https://github.com/pmndrs/cannon-es-debugger).

src/objects/Body.ts

@@ -484,12 +484,23 @@ export class Body extends EventTarget {
     }
   }
 
-  applyForce(force: Vec3, relativePoint: Vec3): void {
+  /**
+   * Apply force to a point of the body. This could for example be a point on the Body surface.
+   * Applying force this way will add to Body.force and Body.torque.
+   * @method applyForce
+   * @param  {Vec3} force The amount of force to add.
+   * @param  {Vec3} [relativePoint] A point relative to the center of mass to apply the force on.
+   */
+  applyForce(force: Vec3, relativePoint: Vec3 = new Vec3()): void {
+    // Needed?
     if (this.type !== Body.DYNAMIC) {
-      // Needed?
       return
     }
 
+    if (this.sleepState === Body.SLEEPING) {
+      this.wakeUp()
+    }
+
     // Compute produced rotational force
     const rotForce = Body_applyForce_rotForce
     relativePoint.cross(force, rotForce)
@@ -501,7 +512,13 @@ export class Body extends EventTarget {
     this.torque.vadd(rotForce, this.torque)
   }
 
-  applyLocalForce(localForce: Vec3, localPoint: Vec3): void {
+  /**
+   * Apply force to a local point in the body.
+   * @method applyLocalForce
+   * @param  {Vec3} force The force vector to apply, defined locally in the body frame.
+   * @param  {Vec3} [localPoint] A local point in the body to apply the force on.
+   */
+  applyLocalForce(localForce: Vec3, localPoint: Vec3 = new Vec3()): void {
     if (this.type !== Body.DYNAMIC) {
       return
     }
@@ -516,11 +533,23 @@ export class Body extends EventTarget {
     this.applyForce(worldForce, relativePointWorld)
   }
 
-  applyImpulse(impulse: Vec3, relativePoint: Vec3): void {
+  /**
+   * Apply impulse to a point of the body. This could for example be a point on the Body surface.
+   * An impulse is a force added to a body during a short period of time (impulse = force * time).
+   * Impulses will be added to Body.velocity and Body.angularVelocity.
+   * @method applyImpulse
+   * @param  {Vec3} impulse The amount of impulse to add.
+   * @param  {Vec3} relativePoint A point relative to the center of mass to apply the force on.
+   */
+  applyImpulse(impulse: Vec3, relativePoint: Vec3 = new Vec3()): void {
     if (this.type !== Body.DYNAMIC) {
       return
     }
 
+    if (this.sleepState === Body.SLEEPING) {
+      this.wakeUp()
+    }
+
     // Compute point position relative to the body center
     const r = relativePoint
 
@@ -547,7 +576,13 @@ export class Body extends EventTarget {
     this.angularVelocity.vadd(rotVelo, this.angularVelocity)
   }
 
-  applyLocalImpulse(localImpulse: Vec3, localPoint: Vec3): void {
+  /**
+   * Apply locally-defined impulse to a local point in the body.
+   * @method applyLocalImpulse
+   * @param  {Vec3} force The force vector to apply, defined locally in the body frame.
+   * @param  {Vec3} localPoint A local point in the body to apply the force on.
+   */
+  applyLocalImpulse(localImpulse: Vec3, localPoint: Vec3 = new Vec3()): void {
     if (this.type !== Body.DYNAMIC) {
       return
     }
@@ -738,38 +773,14 @@ const uiw_m1 = new Mat3()
 const uiw_m2 = new Mat3()
 const uiw_m3 = new Mat3()
 
-/**
- * Apply force to a world point. This could for example be a point on the Body surface. Applying force this way will add to Body.force and Body.torque.
- * @method applyForce
- * @param  {Vec3} force The amount of force to add.
- * @param  {Vec3} relativePoint A point relative to the center of mass to apply the force on.
- */
 const Body_applyForce_rotForce = new Vec3()
 
-/**
- * Apply force to a local point in the body.
- * @method applyLocalForce
- * @param  {Vec3} force The force vector to apply, defined locally in the body frame.
- * @param  {Vec3} localPoint A local point in the body to apply the force on.
- */
 const Body_applyLocalForce_worldForce = new Vec3()
 const Body_applyLocalForce_relativePointWorld = new Vec3()
 
-/**
- * Apply impulse to a world point. This could for example be a point on the Body surface. An impulse is a force added to a body during a short period of time (impulse = force * time). Impulses will be added to Body.velocity and Body.angularVelocity.
- * @method applyImpulse
- * @param  {Vec3} impulse The amount of impulse to add.
- * @param  {Vec3} relativePoint A point relative to the center of mass to apply the force on.
- */
 const Body_applyImpulse_velo = new Vec3()
 const Body_applyImpulse_rotVelo = new Vec3()
 
-/**
- * Apply locally-defined impulse to a local point in the body.
- * @method applyLocalImpulse
- * @param  {Vec3} force The force vector to apply, defined locally in the body frame.
- * @param  {Vec3} localPoint A local point in the body to apply the force on.
- */
 const Body_applyLocalImpulse_worldImpulse = new Vec3()
 const Body_applyLocalImpulse_relativePoint = new Vec3()