Merge pull request #1254 from liabru/runner-2

Improve Matter.Runner

Author: liabru

demo/src/Compare.js

@@ -116,7 +116,6 @@ var compare = function(examples, isDev) {
             ticks += 1;
 
             var demoBuildInstance = demoBuild.example.instance;
-            runner.isFixed = demoBuildInstance.runner.isFixed = true;
             runner.delta = demoBuildInstance.runner.delta = 1000 / 60;
 
             window.Matter = MatterBuild;

demo/src/Demo.js

@@ -41,6 +41,22 @@ var demo = function(examples, isDev) {
     document.title = 'Matter.js Demo' + (isDev ? ' ・ Dev' : '');
 
     if (isDev) {
+        // add delta control
+        Matter.Common.chainPathAfter(MatterTools, 'Gui.create', function() {
+            this.datGui.__folders["Engine"]
+                .add(demo, "delta", 0, 1000 / 55)
+                .onChange(function() {
+                    var runner = demo.example.instance.runner;
+                    runner.delta = demo.delta;
+                })
+                .step(0.001)
+                .listen();
+        });
+
+        Matter.after('Runner.create', function() {
+            demo.delta = this.delta;
+        });
+
         // add compare button
         var buttonSource = demo.dom.buttonSource,
             buttonCompare = buttonSource.cloneNode(true);

examples/index.js

@@ -41,6 +41,7 @@ module.exports = {
     stress2: require('./stress2.js'),
     stress3: require('./stress3.js'),
     stress4: require('./stress4.js'),
+    substep: require('./substep.js'),
     svg: require('./svg.js'),
     terrain: require('./terrain.js'),
     timescale: require('./timescale.js'),

examples/stress3.js

@@ -34,9 +34,7 @@ Example.stress3 = function() {
     Render.run(render);
 
     // create runner
-    var runner = Runner.create({
-        isFixed: true
-    });
+    var runner = Runner.create();
     Runner.run(runner, engine);
 
     // add bodies

examples/stress4.js

@@ -35,9 +35,7 @@ Example.stress4 = function() {
     Render.run(render);
 
     // create runner
-    var runner = Runner.create({
-        isFixed: true
-    });
+    var runner = Runner.create();
 
     Runner.run(runner, engine);
 

examples/substep.js

@@ -0,0 +1,122 @@
+var Example = Example || {};
+
+Example.substep = function() {
+    var Engine = Matter.Engine,
+        Render = Matter.Render,
+        Runner = Matter.Runner,
+        Events = Matter.Events,
+        Composite = Matter.Composite,
+        MouseConstraint = Matter.MouseConstraint,
+        Mouse = Matter.Mouse,
+        Bodies = Matter.Bodies;
+
+    // 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,
+            wireframes: false,
+            showDebug: true,
+            background: '#000',
+            pixelRatio: 2
+        }
+    });
+
+    Render.run(render);
+
+    // create runner with higher precision timestep (requires >= v0.20.0 beta)
+    var runner = Runner.create({
+        // 600Hz delta = 1.666ms = 10upf @ 60fps (i.e. 10x default precision)
+        delta: 1000 / (60 * 10),
+        // 50fps minimum performance target (i.e. budget allows up to ~20ms execution per frame)
+        maxFrameTime: 1000 / 50
+    });
+
+    Runner.run(runner, engine);
+
+    // demo substepping using very thin bodies (than is typically recommended)
+    Composite.add(world, [
+        Bodies.rectangle(250, 250, 300, 1.25, {
+            frictionAir: 0, 
+            friction: 0,
+            restitution: 0.9,
+            angle: 0.5,
+            render: {
+                lineWidth: 0.5,
+                fillStyle: '#f55a3c'
+            }
+        }),
+        Bodies.circle(200, 200, 2.25, {
+            frictionAir: 0, 
+            friction: 0,
+            restitution: 0.9,
+            angle: 0.5,
+            render: {
+                fillStyle: '#fff'
+            }
+        })
+    ]);
+
+    // add bodies
+    Composite.add(world, [
+        Bodies.rectangle(400, 0, 800, 50, { isStatic: true, render: { visible: false } }),
+        Bodies.rectangle(400, 600, 800, 50, { isStatic: true, render: { visible: false } }),
+        Bodies.rectangle(800, 300, 50, 600, { isStatic: true, render: { visible: false } }),
+        Bodies.rectangle(0, 300, 50, 600, { isStatic: true, render: { visible: false } })
+    ]);
+
+    // scene animation
+    Events.on(engine, 'afterUpdate', function(event) {
+        engine.gravity.scale = 0.00035;
+        engine.gravity.x = Math.cos(engine.timing.timestamp * 0.0005);
+        engine.gravity.y = Math.sin(engine.timing.timestamp * 0.0005);
+    });
+
+    // 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.substep.title = 'High Substeps (Low Delta)';
+Example.substep.for = '>=0.20.0';
+
+if (typeof module !== 'undefined') {
+    module.exports = Example.substep;
+}

src/core/Engine.js

@@ -24,6 +24,8 @@ var Body = require('../body/Body');
 
 (function() {
 
+    Engine._deltaMax = 1000 / 60;
+
     /**
      * Creates a new engine. The options parameter is an object that specifies any properties you wish to override the defaults.
      * All properties have default values, and many are pre-calculated automatically based on other properties.
@@ -51,7 +53,8 @@ var Body = require('../body/Body');
                 timestamp: 0,
                 timeScale: 1,
                 lastDelta: 0,
-                lastElapsed: 0
+                lastElapsed: 0,
+                lastUpdatesPerFrame: 0
             }
         };
 
@@ -89,6 +92,13 @@ var Body = require('../body/Body');
             timestamp = timing.timestamp,
             i;
 
+        // warn if high delta
+        if (delta > Engine._deltaMax) {
+            Common.warnOnce(
+                'Matter.Engine.update: delta argument is recommended to be less than or equal to', Engine._deltaMax.toFixed(3), 'ms.'
+            );
+        }
+
         delta = typeof delta !== 'undefined' ? delta : Common._baseDelta;
         delta *= timing.timeScale;