From bc07f56a94c70b6ce78cd8d8dc43dd7922678519 Mon Sep 17 00:00:00 2001
From: liabru <liabru@brm.io>
Date: Sun, 12 Dec 2021 13:19:37 +0000
Subject: [PATCH] added example for Composite.remove

---
 examples/index.js  |   1 +
 examples/remove.js | 138 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 139 insertions(+)
 create mode 100644 examples/remove.js

diff --git a/examples/index.js b/examples/index.js
index e11d4e9..bee420f 100644
--- a/examples/index.js
+++ b/examples/index.js
@@ -27,6 +27,7 @@ module.exports = {
     raycasting: require('./raycasting.js'),
     restitution: require('./restitution.js'),
     rounded: require('./rounded.js'),
+    remove: require('./remove.js'),
     sensors: require('./sensors.js'),
     sleeping: require('./sleeping.js'),
     slingshot: require('./slingshot.js'),
diff --git a/examples/remove.js b/examples/remove.js
new file mode 100644
index 0000000..6fac386
--- /dev/null
+++ b/examples/remove.js
@@ -0,0 +1,138 @@
+var Example = Example || {};
+
+Example.remove = function() {
+    var Engine = Matter.Engine,
+        Render = Matter.Render,
+        Runner = Matter.Runner,
+        Composites = Matter.Composites,
+        Common = Matter.Common,
+        MouseConstraint = Matter.MouseConstraint,
+        Mouse = Matter.Mouse,
+        Composite = Matter.Composite,
+        Bodies = Matter.Bodies,
+        Events = Matter.Events;
+
+    // create engine
+    var engine = Engine.create(),
+        world = engine.world;
+
+    // create renderer
+    var render = Render.create({
+        element: document.body,
+        engine: engine,
+        options: {
+            width: 800,
+            height: 600,
+            showAngleIndicator: true,
+        }
+    });
+
+    Render.run(render);
+
+    // create runner
+    var runner = Runner.create();
+    Runner.run(runner, engine);
+
+    var stack = null,
+        updateCount = 0;
+
+    var createStack = function() {
+        return Composites.stack(20, 20, 10, 5, 0, 0, function(x, y) {
+            var sides = Math.round(Common.random(1, 8));
+
+            // round the edges of some bodies
+            var chamfer = null;
+            if (sides > 2 && Common.random() > 0.7) {
+                chamfer = {
+                    radius: 10
+                };
+            }
+
+            switch (Math.round(Common.random(0, 1))) {
+            case 0:
+                if (Common.random() < 0.8) {
+                    return Bodies.rectangle(x, y, Common.random(25, 50), Common.random(25, 50), { chamfer: chamfer });
+                } else {
+                    return Bodies.rectangle(x, y, Common.random(80, 120), Common.random(25, 30), { chamfer: chamfer });
+                }
+            case 1:
+                return Bodies.polygon(x, y, sides, Common.random(25, 50), { chamfer: chamfer });
+            }
+        });
+    };
+
+    // add and remove stacks every few updates
+    Events.on(engine, 'afterUpdate', function() {
+        // limit rate
+        if (stack && updateCount <= 50) {
+            updateCount += 1;
+            return;
+        }
+
+        updateCount = 0;
+
+        // remove last stack
+        if (stack) {
+            Composite.remove(world, stack);
+        }
+
+        // create a new stack
+        stack = createStack();
+
+        // add the new stack
+        Composite.add(world, stack);
+    });
+
+    // add another stack that will not be removed
+    Composite.add(world, createStack());
+
+    Composite.add(world, [
+        // walls
+        Bodies.rectangle(400, 0, 800, 50, { isStatic: true }),
+        Bodies.rectangle(400, 600, 800, 50, { isStatic: true }),
+        Bodies.rectangle(800, 300, 50, 600, { isStatic: true }),
+        Bodies.rectangle(0, 300, 50, 600, { isStatic: true })
+    ]);
+
+    // add mouse control
+    var mouse = Mouse.create(render.canvas),
+        mouseConstraint = MouseConstraint.create(engine, {
+            mouse: mouse,
+            constraint: {
+                stiffness: 0.2,
+                render: {
+                    visible: false
+                }
+            }
+        });
+
+    Composite.add(world, mouseConstraint);
+
+    // keep the mouse in sync with rendering
+    render.mouse = mouse;
+
+    // fit the render viewport to the scene
+    Render.lookAt(render, {
+        min: { x: 0, y: 0 },
+        max: { x: 800, y: 600 }
+    });
+
+    // context for MatterTools.Demo
+    return {
+        engine: engine,
+        runner: runner,
+        render: render,
+        canvas: render.canvas,
+        stop: function() {
+            Matter.Render.stop(render);
+            Matter.Runner.stop(runner);
+        }
+    };
+};
+
+Example.remove.title = 'Composite Remove';
+Example.remove.for = '>=0.14.2';
+
+if (typeof module !== 'undefined') {
+    module.exports = Example.remove;
+}