salat-first/dist/core/shadow.js

Islamic prayer times calculation with special support for Moroccan methods and Maliki madhab

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.ShadowMethod = void 0;
exports.getShadowLengthMultiplier = getShadowLengthMultiplier;
exports.calculateAsrAngle = calculateAsrAngle;
const math_1 = require("./math");
/**
 * Shadow length calculation methods
 */
var ShadowMethod;
(function (ShadowMethod) {
    /**
     * Shafi, Maliki, and Hanbali madhabs use this method
     * Asr time starts when shadow length equals object height plus shadow length at noon
     */
    ShadowMethod["Standard"] = "standard";
    /**
     * Hanafi madhab uses this method
     * Asr time starts when shadow length equals twice object height plus shadow length at noon
     */
    ShadowMethod["Hanafi"] = "hanafi";
})(ShadowMethod || (exports.ShadowMethod = ShadowMethod = {}));
/**
 * Calculates the shadow length for Asr prayer
 * @param method The shadow calculation method
 * @returns The shadow length multiplier
 */
function getShadowLengthMultiplier(method) {
    switch (method) {
        case ShadowMethod.Standard:
            return 1;
        case ShadowMethod.Hanafi:
            return 2;
        default:
            throw new Error(`Unknown shadow method: ${method}`);
    }
}
/**
 * Calculates the angle for Asr prayer based on shadow length
 * @param latitude The latitude in degrees
 * @param declination The solar declination in degrees
 * @param shadowLength The shadow length multiplier
 * @returns The angle in degrees
 */
function calculateAsrAngle(latitude, declination, shadowLength) {
    const tangent = Math.abs(latitude - declination);
    const inverse = shadowLength + Math.tan((0, math_1.degreesToRadians)(tangent));
    return (0, math_1.radiansToDegrees)(Math.atan(1.0 / inverse));
}