首发于Enaium的个人博客
好了，我们已经完成了所有的准备工作，现在我们可以开始编写启动游戏的代码了。
首先我们需要添加几个依赖。
model = { path = "../model" }
parse = { path = "../parse" }
download = { path = "../download" }
clap = { version = "4.5" }
zip = "2.1"
clap用于解析命令行参数，zip用于解压文件。
首先创建一个cli函数用于构建我们的命令行。
fn cli() -> Command {
Command::new("rmcl")
.about("A Minecraft launcher written in Rust")
.version("0.1.0")
.author("Enaium")
.subcommand_required(true)
.arg_required_else_help(true)
.allow_external_subcommands(true)
.subcommand(
Command::new("search")
.about("Search Game")
.arg(arg!([VERSION] "Game version"))
.arg(
arg!(-t --type <TYPE> "Game type")
.value_parser(["release", "snapshot", "old_beta", "old_alpha"])
.require_equals(true)
.default_value("release")
.default_missing_value("release"),
),
)
.subcommand(
Command::new("download")
.about("Download Game")
.arg(arg!(<VERSION> "Game Version"))
.arg_required_else_help(true),
)
.subcommand(
Command::new("launch")
.about("Launch Game")
.arg(arg!(<VERSION> "Game Version"))
.arg_required_else_help(true),
)
}
接着创建一个get_version_manifest函数用于获取游戏的所有版本清单。
fn get_version_manifest() -> model::version_manifest::VersionManifest {
return get("https://launchermeta.mojang.com/mc/game/version_manifest.json")
.unwrap()
.json::<version_manifest::VersionManifest>()
.unwrap();
}
之后编写每个子命令的处理函数。
fn search(sub_matches: &clap::ArgMatches) {
let version = sub_matches.get_one::<String>("VERSION");
let type_ = sub_matches.get_one::<String>("type").unwrap();
let versions = get_version_manifest().versions;
let versions = versions.iter().filter(|v| {
(if version.is_some() {
v.id.contains(version.unwrap())
} else {
true
}) && v.type_.eq(type_)
});
for version in versions {
println!("Version:{}", version.id);
}
}
fn download(sub_matches: &clap::ArgMatches) {
let game_dir = std::env::current_dir().unwrap().join(".minecraft");
let version = sub_matches.get_one::<String>("VERSION").unwrap();
let versions = get_version_manifest().versions;
if let Some(version) = versions.iter().find(|v| v.id.eq(version)) {
version.download(&game_dir).unwrap_or_else(|err| {
panic!("Version download error:{:?}", err);
});
} else {
println!("Version:{} not found", version);
}
}
fn launch(sub_matches: &clap::ArgMatches) {
let game_dir = std::env::current_dir().unwrap().join(".minecraft");
let libraries_dir = game_dir.join("libraries");
let assets_dir = game_dir.join("assets");
let version = sub_matches.get_one::<String>("VERSION").unwrap();
let version_dir = game_dir.join("versions").join(version);
let natives_dir = version_dir.join("natives");
let config_path = version_dir.join(format!("{}.json", version));
let version_path = version_dir.join(format!("{}.jar", version));
if !version_path.exists() || !config_path.exists() {
println!("Version:{} not found", version_path.display());
return;
}
let version = &Version::parse(&std::fs::read_to_string(&config_path).unwrap()).unwrap();
for library in &version.libraries {
if library.allowed() && library.name.contains("natives") {
extract_jar(
&libraries_dir.join(&library.downloads.artifact.path),
&natives_dir,
);
}
}
let classpath = format!(
"{}{}",
&version
.libraries
.iter()
.map(|library| {
format!(
"{}{}",
libraries_dir
.join(&library.downloads.artifact.path)
.display(),
if cfg!(windows) { ";" } else { ":" }
)
})
.collect::<String>(),
version_path.display()
);
std::process::Command::new("java")
.current_dir(&game_dir)
.arg(format!("-Djava.library.path={}", natives_dir.display()))
.arg("-Dminecraft.launcher.brand=rmcl")
.arg("-cp")
.arg(classpath)
.arg(&version.main_class)
.arg("--username")
.arg("Enaium")
.arg("--version")
.arg(&version.id)
.arg("--gameDir")
.arg(game_dir)
.arg("--assetsDir")
.arg(assets_dir)
.arg("--assetIndex")
.arg(&version.asset_index.id)
.arg("--accessToken")
.arg("0")
.arg("--versionType")
.arg("RMCL 0.1.0")
.status()
.unwrap();
}
解压natives文件。
fn extract_jar(jar: &Path, dir: &Path) {
if !dir.exists() {
std::fs::create_dir_all(dir).unwrap();
}
let mut archive = zip::ZipArchive::new(std::fs::File::open(jar).unwrap()).unwrap();
for i in 0..archive.len() {
let mut entry = archive.by_index(i).unwrap();
if entry.is_file() && !entry.name().contains("META-INF") {
let mut name = entry.name();
if name.contains("/") {
name = &name[entry.name().rfind('/').unwrap() + 1..];
}
let path = dir.join(name);
if path.exists() {
std::fs::remove_file(&path).unwrap();
}
let mut file = std::fs::File::create(&path).unwrap();
std::io::copy(&mut entry, &mut file).unwrap();
}
}
}
最后在main函数中调用cli函数。
fn main() {
let matches = cli().get_matches();
match matches.subcommand() {
Some(("search", sub_matches)) => {
search(sub_matches);
}
Some(("download", sub_matches)) => {
download(sub_matches);
}
Some(("launch", sub_matches)) => {
launch(sub_matches);
}
_ => unreachable!(),
}
}
现在我们可以使用rmcl命令来搜索、下载、启动游戏了。
