vgm-conv/dist/converter/opl-clock-converter.js

Chip-type and clock converter for VGM.

"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.OPLClockConverter = void 0;
const vgm_converter_1 = require("./vgm-converter");
const vgm_parser_1 = require("vgm-parser");
const vgm_write_data_buffer_1 = __importDefault(require("./vgm-write-data-buffer"));
class OPLClockConverter extends vgm_converter_1.VGMClockConverter {
    _ratio;
    _regs = new Uint8Array(256);
    _buf;
    constructor(from, to, opts) {
        super(from, to.clock, (to.chip === "ymf262" ? 4 : 1) * 3579545);
        this._ratio = this.to.clock / from.clock;
        this._buf = new vgm_write_data_buffer_1.default(256, to.chip === "ymf262" ? 2 : 1);
    }
    convertWriteDataCommand(cmd) {
        if (this._ratio !== 1.0) {
            if (0xa0 <= cmd.addr && cmd.addr < 0xc0) {
                this._regs[cmd.addr] = cmd.data;
                const al = cmd.addr & 0xaf;
                const ah = (cmd.addr & 0xaf) + 0x10;
                const fnum = ((this._regs[ah] & 3) << 8) | this._regs[al];
                let new_fnum = Math.round(fnum / this._ratio);
                let new_blk = (this._regs[ah] & 0x1c) >> 2;
                while (new_fnum > 0x3ff) {
                    new_fnum >>= 1;
                    new_blk++;
                }
                if (new_blk > 7) {
                    new_blk = 7;
                    new_fnum = 0x3ff;
                }
                const dl = new_fnum & 0xff;
                const dh = (this._regs[ah] & 0xe0) | (new_blk << 2) | (new_fnum >> 8);
                this._buf.push(cmd.copy({ addr: ah, data: dh }));
                this._buf.push(cmd.copy({ addr: al, data: dl }));
                return this._buf.commit();
            }
        }
        return [cmd];
    }
    convertCommand(cmd) {
        if (cmd instanceof vgm_parser_1.VGMWriteDataCommand && cmd.chip === this.to.chip && cmd.index === this.from.index) {
            return this.convertWriteDataCommand(cmd);
        }
        return [cmd];
    }
}
exports.OPLClockConverter = OPLClockConverter;