/// <summary>
/// Patches the given minecraft version and returns the new patched version.
/// The patcher will create a new version directory and create a new jar file.
/// The jar file is based on the original <paramref name="version"/>.
/// The patcher will copy any assets from the orignal jar file.
/// The content of the META-INF directory will not be copied.
/// All classes will be analysed and scanned for a keyPressed method.
/// The patcher will replace 0x110102 from the keyPressed methods.
/// 0x11 (sipush) is the java bytecode instruction that loads the next two
/// bytes as short value onto the stack. Where 0x0102 is the short value for
/// 258 which is the minecraft keycode for tab. 0x0102 will be replaced with
/// 0xFFFF which is an invalid keycode.
/// </summary>
/// <param name="version"></param>
/// <param name="postfix"></param>
/// <returns></returns>
private static MinecraftVersion Patch(MinecraftVersion version, string postfix)
{
Console.WriteLine("Start pathching '{0}'...", version.ID);
Console.WriteLine("------------------------------------------------------");
// Creates a new version
var parentPath = Path.GetDirectoryName(version.Path);
// Searches for the next free directory.
// Is this really necessary?
var template = version.ID + "-" + postfix;
var id = template;
var path = Path.Combine(parentPath, id);
var counter = 1;
while (Directory.Exists(path))
{
counter++;
id = template + counter;
path = Path.Combine(parentPath, id);
}
Console.WriteLine("Creating patched version '{0}'...", id);
// Creates the patched version
var patchedVersion = new MinecraftVersion(path);
// The copy buffer
var buffer = new byte[1024 * 8];
// Opens the java file
using (var javaFile = version.OpenJavaFile())
{
// Creates the output file
using (var output = new FileStream(patchedVersion.PathJar, FileMode.Create))
{
// Creates the output zip stream
using (var outputZip = new ZipOutputStream(output))
{
// Do not use 64 bit zip
outputZip.UseZip64 = UseZip64.Off;
var files = javaFile.Zip.Count;
for (int i = 0; i < files; i++)
{
var entry = javaFile.Zip[i];
// Ignore the META-INF folder
if (entry.Name.Contains("META-INF/"))
{
continue;
}
// Creates the output entry file
var outputEntry = new ZipEntry(entry.Name);
outputEntry.DateTime = entry.DateTime;
outputEntry.Size = entry.Size;
outputZip.PutNextEntry(outputEntry);
// This is a class file
if (Path.GetExtension(entry.Name) == ".class")
{
// Loads the class
var javaClass = javaFile.GetClass(entry);
// Gets the class info
var javaClassInfo = javaClass.GetConstant <JavaConstantClassInfo>(javaClass.ThisClass);
var javaClassName = javaClass.GetConstantUtf8(javaClassInfo.NameIndex);
// Gets the method
var javaMethod = javaClass.GetMethod("keyPressed");
if (javaMethod != null)
{
// Gets the method info
var javaMethodName = javaClass.GetConstantUtf8(javaMethod.NameIndex);
var javaMethodDescriptor = javaClass.GetConstantUtf8(javaMethod.DescriptorIndex);
// Gets the code attribute of the method
var javaCodeAttribute = javaMethod.GetCodeAttribute();
if (javaCodeAttribute != null)
{
var code = javaCodeAttribute.Code;
var index = 0;
while ((index = Utils.BinaryIndexOf(code, OrginalCode, index)) >= 0)
{
Console.WriteLine("Patching bytecode from '{0}.{1}{2}' at position {3}...", javaClassName, javaMethodName, javaMethodDescriptor, index);
// Change the code
code[index + 1] = 0xFF;
code[index + 2] = 0xFF;
index++;
}
}
}
// Writes the class
javaClass.Write(outputZip);
}
else
{
// Just copy the file
using (var inputStream = javaFile.GetFileStream(entry))
{
StreamUtils.Copy(inputStream, outputZip, buffer);
}
}
}
}
}
}
Console.WriteLine("Creating json file...");
// Creates the json file
var patchedInfo = new MinecraftVersionInfo()
{
ID = id,
InheritsFrom = version.ID,
Type = "custom",
MainClass = "net.minecraft.client.main.Main",
MinimumLauncherVersion = 21,
};
// Write the version json
patchedVersion.WriteJsonFile(patchedInfo);
Console.WriteLine("Version got patched!");
return(patchedVersion);
}