6584d8d064
Right-click or long-press the d20 button (per-combatant or Roll All) to open a context menu with Advantage and Disadvantage options. Normal left-click behavior is unchanged. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
38 lines
1.0 KiB
TypeScript
38 lines
1.0 KiB
TypeScript
import type { DomainError } from "./types.js";
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export type RollMode = "normal" | "advantage" | "disadvantage";
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/**
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* Selects the effective roll from two dice values based on the roll mode.
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* Advantage takes the higher, disadvantage takes the lower.
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*/
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export function selectRoll(
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roll1: number,
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roll2: number,
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mode: RollMode,
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): number {
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if (mode === "advantage") return Math.max(roll1, roll2);
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if (mode === "disadvantage") return Math.min(roll1, roll2);
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return roll1;
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}
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/**
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* Pure function that computes initiative from a resolved dice roll and modifier.
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* The dice roll must be an integer in [1, 20].
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* Returns the sum (diceRoll + modifier) or a DomainError for invalid inputs.
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*/
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export function rollInitiative(
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diceRoll: number,
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modifier: number,
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): number | DomainError {
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if (!Number.isInteger(diceRoll) || diceRoll < 1 || diceRoll > 20) {
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return {
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kind: "domain-error",
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code: "invalid-dice-roll",
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message: `Dice roll must be an integer between 1 and 20, got ${diceRoll}`,
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};
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}
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return diceRoll + modifier;
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}
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