furnace-module-interface/build/song.js

An interface for loading, processing and saving furnace modules in an object-oriented manner. Fully typed via TypeScript.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.FurnaceSong = void 0;
const channels_1 = require("./channels");
const defaults_1 = require("./defaults");
class FurnaceSong {
    constructor() {
        this.timebase = defaults_1.defaults.timebase;
        this.speed1 = defaults_1.defaults.speed1;
        this.speed2 = defaults_1.defaults.speed2;
        this.highlightA = defaults_1.defaults.highlightA;
        this.highlightB = defaults_1.defaults.highlightB;
        this.initialArpeggioTime = 1;
        this.ticksPerSecond = defaults_1.defaults.tps;
        this.virtualTempoNumerator = defaults_1.defaults.tempo;
        this.virtualTempoDenominator = defaults_1.defaults.tempo;
        this.name = defaults_1.defaults.songName;
        this.comment = defaults_1.defaults.songComment;
        this.rows = defaults_1.defaults.rows;
        this.channels = null;
        this.channelInfo = [];
    }
    static create() {
        return new FurnaceSong();
    }
    static fromHelper(helper, info, version) {
        const song = FurnaceSong.create();
        if (FurnaceSong.magic !== helper.getASCII(4)) {
            throw new Error("Expected format magic string \"" + FurnaceSong.magic + "\" when loading a subsong block.");
        }
        helper.skipBytes(4);
        song.timebase = helper.readUInt8() + 1;
        song.speed1 = helper.readUInt8();
        song.speed2 = helper.readUInt8();
        song.initialArpeggioTime = helper.readUInt8();
        song.ticksPerSecond = helper.readFloat32LE();
        song.rows = helper.readUInt16LE();
        const numOrders = helper.readUInt16LE();
        if (song.rows > 256) {
            throw new Error("Expected at most 256 rows in a pattern, but " + song.rows + " were loaded.");
        }
        if (numOrders > 256) {
            throw new Error("Expected at most 256 orders in a subsong, but " + numOrders + " were loaded.");
        }
        song.highlightA = helper.readUInt8();
        song.highlightB = helper.readUInt8();
        song.virtualTempoNumerator = helper.readUInt16LE();
        song.virtualTempoDenominator = helper.readUInt16LE();
        song.name = helper.readString("utf-8");
        song.comment = helper.readString("utf-8");
        song.fetchChannels(helper, version, (0, channels_1.computeChannelCount)(info), numOrders);
        return song;
    }
    fetchChannels(helper, version, channelCount, orderCount) {
        for (let i = 0; i < channelCount; i++) {
            this.channelInfo.push(new channels_1.FurnaceChannelInfo());
        }
        for (let i = 0; i < this.channelInfo.length; i++) {
            this.channelInfo[i].orders = [...helper.readBuffer(orderCount),].map((v) => v & (version < 80 ? 0x7F : 0xFF));
        }
        for (let i = 0; i < this.channelInfo.length; i++) {
            this.channelInfo[i].effects = helper.readUInt8();
        }
        for (let i = 0; i < this.channelInfo.length; i++) {
            this.channelInfo[i].hidden = helper.readUInt8() === 0;
        }
        for (let i = 0; i < this.channelInfo.length; i++) {
            this.channelInfo[i].collapsed = helper.readUInt8() === 0;
        }
        for (let i = 0; i < this.channelInfo.length; i++) {
            this.channelInfo[i].longname = helper.readString("ascii");
        }
        for (let i = 0; i < this.channelInfo.length; i++) {
            this.channelInfo[i].shortname = helper.readString("ascii");
        }
    }
    writeToBuffer(helper) {
        const _begin = helper.getPosition(8);
        helper.writeString(FurnaceSong.magic, "ascii", false);
        helper.skipBytes(4);
        helper.writeUInt8(this.timebase - 1);
        helper.writeUInt8(this.speed1);
        helper.writeUInt8(this.speed2);
        helper.writeUInt8(this.initialArpeggioTime);
        helper.writeFloat32LE(this.ticksPerSecond);
        helper.writeUInt16LE(this.rows);
        helper.writeUInt16LE(this.channelInfo[0].orders.length);
        helper.writeUInt8(this.highlightA);
        helper.writeUInt8(this.highlightB);
        helper.writeUInt16LE(this.virtualTempoNumerator);
        helper.writeUInt16LE(this.virtualTempoDenominator);
        helper.writeString(this.name, "utf-8", true);
        helper.writeString(this.comment, "utf-8", true);
        this.writeChannels(helper);
        helper.writeUInt32LE(helper.getPosition() - _begin, _begin - 4);
    }
    writeChannels(helper) {
        for (let i = 0; i < this.channelInfo.length; i++) {
            helper.writeBuffer(Buffer.from(this.channelInfo[i].orders), 0, this.channelInfo[i].orders.length);
        }
        helper.writeBuffer(Buffer.from(this.channelInfo.map((c) => c.effects)), 0, this.channelInfo.length);
        helper.writeBuffer(Buffer.from(this.channelInfo.map((c) => c.hidden ? 0 : 1)), 0, this.channelInfo.length);
        helper.writeBuffer(Buffer.from(this.channelInfo.map((c) => c.collapsed ? 0 : 1)), 0, this.channelInfo.length);
        for (let i = 0; i < this.channelInfo.length; i++) {
            helper.writeString(this.channelInfo[i].longname, "ascii", true);
        }
        for (let i = 0; i < this.channelInfo.length; i++) {
            helper.writeString(this.channelInfo[i].shortname, "ascii", true);
        }
    }
    getChannels(info) {
        if (this.channels) {
            return this.channels;
        }
        return this.channels = (0, channels_1.computeChannelObjects)(info, this.channelInfo);
    }
}
exports.FurnaceSong = FurnaceSong;
FurnaceSong.magic = "SONG";