protoloon/js/CodecHighResLocation.js

/*
Copyright (c) 2023-forever Douglas Malnati. All rights reserved.

See the /faq/tos page for details.
    
(If this generated header is stamped on a file which is a 3rd party file or under a different license or copyright, then ignore this copyright statement and use that file's terms.)
*/

import { WsprCodecMaker } from '/pro/codec/WsprCodec.js';
import { WSPREncoded } from '/js/WSPREncoded.js';


export class CodecHighResLocation
extends WsprCodecMaker
{
    static HDR_TYPE = 3;
    static HDR_TELEMETRY_TYPE = 0;
    static HDR_RESERVED = 0;
    static REFERENCE_RESERVED = 0;
    static REFERENCE_ESTABLISHED_GRID4 = 1;
    static REFERENCE_GRID_WIDTH_DEG = 2;
    static REFERENCE_GRID_HEIGHT_DEG = 1;

    constructor()
    {
        super();

        this.SetCodecDefFragment("HighResLocation", `
            { "name": "Reference", "unit": "Enum", "lowValue": 0, "highValue":     1, "stepSize": 1 },
            { "name": "Latitude",  "unit": "Idx",  "lowValue": 0, "highValue": 12352, "stepSize": 1 },
            { "name": "Longitude", "unit": "Idx",  "lowValue": 0, "highValue": 24617, "stepSize": 1 },
        `);
    }

    GetReferenceReservedValue()
    {
        return CodecHighResLocation.REFERENCE_RESERVED;
    }

    GetHdrTypeValue()
    {
        return CodecHighResLocation.HDR_TYPE;
    }

    GetHdrTelemetryTypeValue()
    {
        return CodecHighResLocation.HDR_TELEMETRY_TYPE;
    }

    GetHdrReservedValue()
    {
        return CodecHighResLocation.HDR_RESERVED;
    }

    GetReferenceEstablishedGrid4Value()
    {
        return CodecHighResLocation.REFERENCE_ESTABLISHED_GRID4;
    }

    GetReferencedGridWidthDeg()
    {
        return CodecHighResLocation.REFERENCE_GRID_WIDTH_DEG;
    }

    GetReferencedGridHeightDeg()
    {
        return CodecHighResLocation.REFERENCE_GRID_HEIGHT_DEG;
    }

    GetLatitudeBinCount()
    {
        let codec = this.GetCodecInstance();

        return codec.GetLatitudeIdxHighValue() - codec.GetLatitudeIdxLowValue() + 1;
    }

    GetLongitudeBinCount()
    {
        let codec = this.GetCodecInstance();

        return codec.GetLongitudeIdxHighValue() - codec.GetLongitudeIdxLowValue() + 1;
    }

    GetReferenceGridSouthwestCorner(grid4)
    {
        return WSPREncoded.DecodeMaidenheadToDeg(grid4.substring(0, 4), { snap: "southwest" });
    }

    IsCodecHighResLocation(codec)
    {
        return codec?.GetHdrTypeEnum?.() == this.GetHdrTypeValue();
    }

    IsReferenceEstablishedGrid4(referenceEnum)
    {
        return Number(referenceEnum) == this.GetReferenceEstablishedGrid4Value();
    }

    EncodeLocationToFieldValues(lat, lng)
    {
        let grid4 = WSPREncoded.GetReferenceGrid4(lat, lng);
        let [baseLat, baseLng] = this.GetReferenceGridSouthwestCorner(grid4);

        let latDegDiff = Number(lat) - baseLat;
        let lngDegDiff = Number(lng) - baseLng;
        let latIsInBounds = latDegDiff >= 0 && latDegDiff < this.GetReferencedGridHeightDeg();
        let lngIsInBounds = lngDegDiff >= 0 && lngDegDiff < this.GetReferencedGridWidthDeg();

        if (!latIsInBounds || !lngIsInBounds)
        {
            throw new RangeError(
                `Location ${lat}, ${lng} is outside reference grid ${grid4}.`
            );
        }

        let latitudeIdx = Math.floor(latDegDiff * this.GetLatitudeBinCount() / this.GetReferencedGridHeightDeg());
        let longitudeIdx = Math.floor(lngDegDiff * this.GetLongitudeBinCount() / this.GetReferencedGridWidthDeg());

        return {
            grid4,
            referenceEnum: this.GetReferenceEstablishedGrid4Value(),
            latitudeIdx,
            longitudeIdx,
        };
    }

    DecodeFieldValuesToLocation(grid4, referenceEnum, latitudeIdx, longitudeIdx)
    {
        if (!this.IsReferenceEstablishedGrid4(referenceEnum))
        {
            return null;
        }

        latitudeIdx = Number(latitudeIdx);
        longitudeIdx = Number(longitudeIdx);

        if (isNaN(latitudeIdx) || isNaN(longitudeIdx))
        {
            return null;
        }

        let [baseLat, baseLng] = this.GetReferenceGridSouthwestCorner(grid4);

        let lat = baseLat + (latitudeIdx + 0.5) * this.GetReferencedGridHeightDeg() / this.GetLatitudeBinCount();
        let lng = baseLng + (longitudeIdx + 0.5) * this.GetReferencedGridWidthDeg() / this.GetLongitudeBinCount();

        return {
            lat,
            lng,
        };
    }

}