27 lines
1.0 KiB
TypeScript
27 lines
1.0 KiB
TypeScript
import type { GameConfig } from "@deadhead/content";
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/**
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* Times are milliseconds since the Unix epoch. A real time is a wall-clock
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* instant; a game time is the instant of the in-game (ephemeris) date, so
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* `new Date(gameTime)` is the in-game date.
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*/
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export type RealTime = number;
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export type GameTime = number;
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export const MS_PER_MINUTE = 60_000;
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export const MS_PER_HOUR = 3_600_000;
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/** Converts a real instant to the in-game instant it maps to. */
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export function realToGame(real: RealTime, config: GameConfig): GameTime {
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const realStart = Date.parse(config.epoch.realStart);
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const gameStart = Date.parse(config.epoch.ephemerisDate);
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return gameStart + (real - realStart) * config.timeCompression;
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}
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/** Converts an in-game instant back to the real instant it maps to. */
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export function gameToReal(game: GameTime, config: GameConfig): RealTime {
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const realStart = Date.parse(config.epoch.realStart);
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const gameStart = Date.parse(config.epoch.ephemerisDate);
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return realStart + (game - gameStart) / config.timeCompression;
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}
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