Implement VirtualCar

demo/src/main/kotlin/ru/mipt/npm/controls/demo/virtual_car/VirtualCar.kt

@@ -0,0 +1,74 @@
+package ru.mipt.npm.controls.demo.virtual_car
+
+import kotlinx.coroutines.launch
+import ru.mipt.npm.controls.properties.*
+import space.kscience.dataforge.meta.Meta
+import space.kscience.dataforge.meta.double
+import space.kscience.dataforge.meta.get
+import space.kscience.dataforge.meta.transformations.MetaConverter
+import java.time.Instant
+import kotlin.time.Duration
+import kotlin.time.ExperimentalTime
+
+class VirtualCar : DeviceBySpec<VirtualCar>(VirtualCar) {
+    private var speedState: Pair<Double, Double> = Pair(0.0, 0.0)
+    get() {
+        val previous_speed = field
+        val current_acceleration = this.accelerationState
+        val now = Instant.now().toEpochMilli().toDouble()
+        val time_difference = now - this.timeState
+        this.timeState = now
+        field = Pair(
+            previous_speed.first + time_difference * current_acceleration.first,
+            previous_speed.second + time_difference * current_acceleration.second
+        )
+        return field
+    }
+
+    private var accelerationState: Pair<Double, Double> = Pair(0.0, 0.0)
+    set(value) {
+        this.speedState
+        field = value
+    }
+
+    private var timeState = Instant.now().toEpochMilli().toDouble()
+
+    object DoublePairMetaConverter : MetaConverter<Pair<Double, Double>> {
+        override fun metaToObject(meta: Meta): Pair<Double, Double> = Pair(
+            meta["x"].double ?: 0.0,
+            meta["y"].double ?: 0.0
+        )
+
+        override fun objectToMeta(obj: Pair<Double, Double>): Meta = Meta {
+            "x" put obj.first
+            "y" put obj.second
+        }
+
+    }
+
+    companion object : DeviceSpec<VirtualCar>(::VirtualCar) {
+        val speed by property(DoublePairMetaConverter) { this.speedState }
+
+        val acceleration by property(DoublePairMetaConverter, VirtualCar::accelerationState)
+
+        val carProperties by metaProperty {
+            Meta {
+                val time = Instant.now()
+                "time" put time.toEpochMilli()
+                "speed" put DoublePairMetaConverter.objectToMeta(read(speed))
+                "acceleration" put DoublePairMetaConverter.objectToMeta(read(acceleration))
+            }
+        }
+
+        @OptIn(ExperimentalTime::class)
+        override fun VirtualCar.onStartup() {
+            launch {
+                speed.read()
+                acceleration.read()
+            }
+            doRecurring(Duration.milliseconds(50)){
+                carProperties.read()
+            }
+        }
+    }
+}