physics

main.js

@@ -1,58 +1,182 @@
 import * as PIXI from 'pixi.js';
-
+import * as p2 from 'p2'
 import './style.css'
 
+function randomInt(max) {
+  return Math.floor(Math.random() * (max + 1))
+}
 
-// Create the application helper and add its render target to the page
-let app = new PIXI.Application({ width: 640, height: 360 });
+const vw = Math.max(document.documentElement.clientWidth || 0, window.innerWidth || 0)
+const vh = Math.max(document.documentElement.clientHeight || 0, window.innerHeight || 0)
+
+let app = new PIXI.Application({
+  width: vw,
+  height: vh,
+  antialias: true,
+  backgroundColor: 0xffffff
+});
 document.body.appendChild(app.view);
 
-// Create window frame
-let frame = new PIXI.Graphics();
-frame.beginFill(0x666666);
-frame.lineStyle({ color: 0xffffff, width: 4, alignment: 0 });
-frame.drawRect(0, 0, 208, 208);
-frame.position.set(320 - 100, 180 - 100);
-app.stage.addChild(frame);
 
-// Create a graphics object to define our mask
-let mask = new PIXI.Graphics();
-// Add the rectangular area to show
-mask.beginFill(0xffffff);
-mask.drawRect(0,0,200,200);
-mask.endFill();
+class PhysicsObject {
+  body;
+  shape;
+  graphics;
+  parentContainer;
 
-// Add container that will hold our masked content
-let maskContainer = new PIXI.Container();
-// Set the mask to use our graphics object from above
-maskContainer.mask = mask;
-// Add the mask as a child, so that the mask is positioned relative to its parent
-maskContainer.addChild(mask);
-// Offset by the window's frame width
-maskContainer.position.set(4,4);
-// And add the container to the window!
-frame.addChild(maskContainer);
+  constructor(body, shape, graphics) {
+    this.body = body;
+    this.shape = shape;
+    this.graphics = graphics;
 
-// Create contents for the masked container
-let text = new PIXI.Text(
-  'This text will scroll up and be masked, so you can see how masking works.  Lorem ipsum and all that.\n\n' +
-  'You can put anything in the container and it will be masked!',
-  {
-    fontSize: 24,
-    fill: 0x1010ff,
-    wordWrap: true,
-    wordWrapWidth: 180
+    this.body.addShape(this.shape);
+
+    this.graphics.interactive = true;
+    this.graphics.on('click', (e) => {
+      this.body.applyImpulse([0, 25]);
+    })
   }
-);
-text.x = 10;
-maskContainer.addChild(text);
 
-// Add a ticker callback to scroll the text up and down
-let elapsed = 0.0;
+  assign(world, container) {
+    world.addBody(this.body);
+    container.addChild(this.graphics);
+  }
+
+  update() {
+    // Transfer positions of the physics objects to Pixi.js
+    this.graphics.position.x = this.body.position[0];
+    this.graphics.position.y = this.body.position[1];
+    this.graphics.rotation = this.body.angle;
+  }
+}
+
+let worldObjects = [];
+
+let zoom = 15;
+let world = new p2.World({ gravity: [0, -9.81] });
+// Add a plane
+
+// let planeShape = new p2.Plane();
+// let planeBody = new p2.Body({
+//   position: [0, -2]
+// });
+// planeBody.addShape(planeShape);
+// world.addBody(planeBody);
+
+let container = new PIXI.Container();
+container.interactive = true;
+container.position.x = app.renderer.width / 2; // center at origin
+container.position.y = app.renderer.height / 2 + 50; 
+container.scale.x = zoom; // zoom in
+container.scale.y = -zoom; // Note: we flip the y axis to make "up" the physics "up"
+container.on('mousedown', e => {
+  console.log(e.data.global.x, e.data.global.y)
+})
+app.stage.addChild(container);
+
+// Add a box
+let box = new PhysicsObject(
+  new p2.Body({
+    mass: 1,
+    position: [0, 2],
+    angularVelocity: 1
+  }),
+  new p2.Box({
+    width: 2,
+    height: 1
+  }),
+  new PIXI.Graphics()
+)
+box.graphics.beginFill(randomInt(0xffffff));
+box.graphics.drawRect(
+  -box.shape.width / 2, -box.shape.height / 2,
+  box.shape.width, box.shape.height);
+box.graphics.endFill();
+
+box.assign(world, container);
+worldObjects.push(box);
+
+let box2 = new PhysicsObject(
+  new p2.Body({
+    mass: 2,
+    position: [-1, 3],
+    angularVelocity: 0
+  }),
+  new p2.Box({
+    width: 2,
+    height: 1
+  }),
+  new PIXI.Graphics()
+)
+box2.graphics.beginFill(0x00ff00);
+box2.graphics.drawRect(
+  -box.shape.width / 2, -box.shape.height / 2,
+  box.shape.width, box.shape.height);
+box2.graphics.endFill();
+
+box2.assign(world, container);
+worldObjects.push(box2);
+
+
+// static ground box
+let box3 = new PhysicsObject(
+  new p2.Body({
+    mass: 0,
+    position: [0, -2]
+  }),
+  new p2.Box({
+    width: 50,
+    height: 0.2
+  }),
+  new PIXI.Graphics()
+)
+box3.graphics.beginFill(0x666666);
+box3.graphics.drawRect(
+  -box3.shape.width / 2, -box3.shape.height / 2,
+  box3.shape.width, box3.shape.height);
+box3.graphics.endFill();
+
+box3.assign(world, container);
+worldObjects.push(box3);
+
 app.ticker.add((delta) => {
-  // Update the text's y coordinate to scroll it
-  elapsed += delta;
-  text.y = 10 + -100.0 + Math.cos(elapsed/50.0) * 100.0;
+  world.step(1 / 60);
+  worldObjects.forEach(o => o.update());
 });
 
+function randomBox() {
+  let width = 1 + Math.random() * 3;
+  let height = 1 + Math.random() * 3;
+  // Add a box
+  let box = new PhysicsObject(
+    new p2.Body({
+      mass: 0.5 * Math.sqrt(width * height),
+      position: [randomInt(25) - 12.5, randomInt(10) + 5],
+      angularVelocity: 0
+    }),
+    new p2.Box({
+      width: width,
+      height: height
+    }),
+    new PIXI.Graphics()
+  )
+  box.graphics.beginFill(randomInt(0xffffff));
+  box.graphics.drawRect(
+    -box.shape.width / 2, -box.shape.height / 2,
+    box.shape.width, box.shape.height);
+  box.graphics.endFill();
 
+  box.assign(world, container);
+  worldObjects.push(box);
+
+  return box;
+}
+
+function doZoom(e) {
+  zoom += -e.deltaY * 0.05;
+  zoom = Math.min(Math.max(1, zoom), 100)
+  container.scale.x = zoom; // zoom in
+  container.scale.y = -zoom; // Note: we flip the y axis to make "up" the physics 
+}
+window.addEventListener('wheel', doZoom)
+window.addEventListener('click', randomBox)

package.json

@@ -10,6 +10,7 @@
     "vite": "^2.5.2"
   },
   "dependencies": {
+    "p2": "^0.7.1",
     "pixi.js": "^6.1.2"
   }
 }

style.css

@@ -1,8 +1,3 @@
-#app {
-  font-family: Avenir, Helvetica, Arial, sans-serif;
-  -webkit-font-smoothing: antialiased;
-  -moz-osx-font-smoothing: grayscale;
-  text-align: center;
-  color: #2c3e50;
-  margin-top: 60px;
-}
+body {
+  margin: 0; padding: 0; overflow: hidden;
+}

yarn.lock

@@ -251,6 +251,13 @@ object-assign@^4.1.1:
   resolved "https://registry.yarnpkg.com/object-assign/-/object-assign-4.1.1.tgz#2109adc7965887cfc05cbbd442cac8bfbb360863"
   integrity sha1-IQmtx5ZYh8/AXLvUQsrIv7s2CGM=
 
+p2@^0.7.1:
+  version "0.7.1"
+  resolved "https://registry.yarnpkg.com/p2/-/p2-0.7.1.tgz#25f2474d9bc3a6d3140a1da26a67c9e118ac9543"
+  integrity sha1-JfJHTZvDptMUCh2iamfJ4RislUM=
+  dependencies:
+    poly-decomp "0.1.1"
+
 path-parse@^1.0.6:
   version "1.0.7"
   resolved "https://registry.yarnpkg.com/path-parse/-/path-parse-1.0.7.tgz#fbc114b60ca42b30d9daf5858e4bd68bbedb6735"
@@ -297,6 +304,11 @@ pixi.js@^6.1.2:
     "@pixi/ticker" "6.1.2"
     "@pixi/utils" "6.1.2"
 
+poly-decomp@0.1.1:
+  version "0.1.1"
+  resolved "https://registry.yarnpkg.com/poly-decomp/-/poly-decomp-0.1.1.tgz#9f68c4fa558663791c9ba4c2df7283f3096c23c9"
+  integrity sha1-n2jE+lWGY3kcm6TC33KD8wlsI8k=
+
 postcss@^8.3.6:
   version "8.3.6"
   resolved "https://registry.yarnpkg.com/postcss/-/postcss-8.3.6.tgz#2730dd76a97969f37f53b9a6096197be311cc4ea"