:tada: added game loop

src/index.js

@@ -1,6 +1,8 @@
-const { makeContainerT } = require('./system.js')
-const { Container } = require('./container.js')
-const { fill, drain } = require('./utils.js')
+import { EventEmitter } from 'node:events'
+
+import loop from './loop.js'
+import { System, makeContainerT } from './system.js'
+import { Container } from './container.js'
 
 const fromConfig = {
     tank_1: {
@@ -36,23 +38,26 @@ const digestConfig = config => {
 /** Holds systems or containers */
 class Controller {}
 
-mySystem = digestConfig(fromConfig)
-
-console.log('mySystem :>> ', mySystem.inventory)
-console.log('\ntank capacity:>> ', mySystem.containers[0].liquidVolumeCapacity)
-console.log('tank level:>> ', mySystem.containers[0].liquidVolumeFilled)
-console.log('pass:>> ', mySystem.containers[0].liquidVolumeFilled === 0)
+const mySystem = digestConfig(fromConfig)
 
-const postFill = fill({ container: mySystem.containers[0], amount: 10 })
-mySystem.replaceContainer(postFill)
-console.log('\nfilled tank :>> ', mySystem.containers[0].liquidVolumeFilled)
-console.log('pass:>> ', mySystem.containers[0].liquidVolumeFilled === 10)
+// Start the loop!
+const emitter = new EventEmitter()
+emitter.on('onUpdate', ({ delta }) => {
+    const start = Date.now()
+    const milli = 111
+    while (Date.now() < start + milli) {
+        console.log(new Date(start).toISOString())
+        console.log(delta)
+    }
 
-const postDrain = drain({ container: mySystem.containers[0], amount: 3 })
-mySystem.replaceContainer(postDrain)
-console.log('\ndrained tank :>> ', mySystem.containers[0].liquidVolumeFilled)
-console.log('pass:>> ', mySystem.containers[0].liquidVolumeFilled === 7)
+    // Check all inputs
+    // Queue tasks based on inputs
+    // Queue one-off tasks based on date/time
+    // Execute the task queue
+})
+loop.start(emitter)
 
-console.log('\ninputs + outputs')
-console.log('inputs :>> ', mySystem.inputsFor(mySystem.containers[0]))
-console.log('outputs :>> ', mySystem.outputsFor(mySystem.containers[0]))
+setTimeout(function () {
+    console.log('6000ms passed, stopping the game loop')
+    loop.active.splice(loop.active.indexOf(0), 1)
+}, 6000)

src/loop.js

@@ -0,0 +1,45 @@
+const active = []
+const getLoopId = (function () {
+    let staticLoopId = 0
+    return function () {
+        return staticLoopId++
+    }
+})()
+
+/** https://github.com/tangmi/node-gameloop/tree/master */
+const start = emitter => {
+    // FPS
+    const _fps = 20
+    const _tickLength = 1000 / _fps
+    let _lastTick = Date.now()
+    let _loopCount = 0
+
+    let id = getLoopId()
+    active.push(id)
+
+    const run = () => {
+        const now = Date.now()
+        _loopCount++
+        if (_lastTick + _tickLength <= now) {
+            const delta = (now - _lastTick) / 1000
+            _lastTick = now
+
+            emitter.emit('onUpdate', { delta })
+
+            _loopCount = 0
+        }
+
+        if (active.indexOf(id) === -1) {
+            return
+        }
+
+        if (Date.now() - _lastTick < _tickLength - 16) {
+            setTimeout(run)
+        } else {
+            setImmediate(run)
+        }
+    }
+    run()
+}
+
+export default { active, start }

test/system.spec.js

@@ -14,6 +14,12 @@ test('system - instantiates and stores inventory correctly', () => {
     expect(testSystem.outputs).toStrictEqual(['output_test'])
     expect(testSystem.containers[0].id).toStrictEqual('aaa')
 
+    const inputs = testSystem.inputsFor({ id: 'aaa' })
+    expect(inputs).toStrictEqual('input_test')
+
+    const outputs = testSystem.outputsFor({ id: 'aaa' })
+    expect(outputs).toStrictEqual('output_test')
+
     testSystem.remove('aaa')
     expect(testSystem.inventory).toStrictEqual({})
 })