| 1 | export class VelocityTracker {
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| 2 | constructor() {
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| 3 | this.history = [];
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| 4 | this.lastPosition = undefined;
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| 5 | this.lastTimestamp = undefined;
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| 6 | }
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| 7 |
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| 8 | add(position) {
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| 9 | const timestamp = new Date().valueOf();
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| 10 | if (this.lastPosition && timestamp > this.lastTimestamp) {
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| 11 | const diff = position - this.lastPosition;
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| 12 | if (diff > 0.001 || diff < -0.001) {
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| 13 | this.history.push(diff / (timestamp - this.lastTimestamp));
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| 14 | }
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| 15 | }
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| 16 | this.lastPosition = position;
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| 17 | this.lastTimestamp = timestamp;
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| 18 | }
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| 19 |
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| 20 | estimateSpeed() {
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| 21 | const finalTrend = this.history.slice(-3);
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| 22 | const sum = finalTrend.reduce((r, v) => r + v, 0);
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| 23 | return sum / finalTrend.length;
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| 24 | }
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| 25 |
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| 26 | reset() {
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| 27 | this.history = [];
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| 28 | this.lastPosition = undefined;
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| 29 | this.lastTimestamp = undefined;
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| 30 | }
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| 31 | }
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