Potential fix for xrandr xvfb on old versions

README.md

@@ -77,7 +77,7 @@ HeadlessMc can run inside Termux.
 * Download the headlessmc-launcher-wrapper.jar into Termux.
 * Disable JLine, as we could not get it to work on Termux for now,
   by adding `hmc.jline.enabled=false` to the HeadlessMC/config.properties.
-* Now you can use HeadlessMc like you do on Desktop or Docker.
+* Now you can use HeadlessMc like you would on Desktop or Docker.
 
 ### Web
 
@@ -87,7 +87,7 @@ but it does not support all features we need to launch the game.
 The CheerpJ instance can be tried out [here](https://3arthqu4ke.github.io/headlessmc/).
 Secondly, there is [container2wasm](https://github.com/headlesshq/hmc-container2wasm),
 which can translate the HeadlessMc Docker container
-to WebAssembly and the run it inside the browser, but this is extremly slow.
+to WebAssembly and the run it inside the browser, but this is extremely slow.
 
 ### Optimizations 
 

headlessmc-launcher/src/main/java/me/earth/headlessmc/launcher/LauncherProperties.java

@@ -97,6 +97,7 @@ public interface LauncherProperties extends HmcProperties {
     Property<Boolean> GAME_DIR_FOR_EACH_VERSION = bool("hmc.game.dir.for.each.version");
 
     Property<Boolean> INSTALL_LOGGING = bool("hmc.install.mc.logging");
+
     Property<Boolean> CHECK_XVFB = bool("hmc.check.xvfb");
 
 }

headlessmc-launcher/src/main/java/me/earth/headlessmc/launcher/instrumentation/InstrumentationHelper.java

@@ -1,22 +1,29 @@
 package me.earth.headlessmc.launcher.instrumentation;
 
+import lombok.CustomLog;
 import lombok.experimental.UtilityClass;
 import lombok.val;
 import me.earth.headlessmc.launcher.instrumentation.log4j.Patchers;
 import me.earth.headlessmc.launcher.instrumentation.lwjgl.HmcLwjglTransformer;
 import me.earth.headlessmc.launcher.instrumentation.modlauncher.BootstrapLauncherTransformer;
 import me.earth.headlessmc.launcher.instrumentation.paulscode.PaulscodeTransformer;
+import me.earth.headlessmc.launcher.instrumentation.xvfb.XvfbLwjglTransformer;
 import me.earth.headlessmc.launcher.launch.LaunchOptions;
+import me.earth.headlessmc.launcher.version.Library;
+import me.earth.headlessmc.launcher.version.family.FamilyUtil;
+import org.jetbrains.annotations.VisibleForTesting;
 
 import java.util.ArrayList;
+import java.util.List;
 
+@CustomLog
 @UtilityClass
 public class InstrumentationHelper {
     public static final String RUNTIME_JAR = "headlessmc-runtime.jar";
     public static final String LWJGL_JAR = "headlessmc-lwjgl.jar";
 
     public static Instrumentation create(LaunchOptions options) {
-        val transformers = new ArrayList<Transformer>(6);
+        val transformers = new ArrayList<Transformer>(8);
         if (options.isLwjgl()) {
             transformers.add(new HmcLwjglTransformer());
             transformers.add(new ResourceExtractor(options.getFiles(), LWJGL_JAR));
@@ -42,7 +49,32 @@ public static Instrumentation create(LaunchOptions options) {
             transformers.add(new BootstrapLauncherTransformer());
         }
 
+        if (options.isXvfb()) {
+            addXvfbTransformer(options, transformers);
+        }
+
         return new Instrumentation(transformers, options.getFiles().getBase());
     }
 
+    @VisibleForTesting
+    static void addXvfbTransformer(LaunchOptions options, List<Transformer> transformers) {
+        log.error("Hello?!");
+        Boolean oldLwjgl = FamilyUtil.iterateParents(options.getVersion(), version -> {
+            for (Library library : version.getLibraries()) {
+                log.error("Cehcking " + library.getName());
+                if ("org.lwjgl.lwjgl".equals(library.getPackage()) && library.getVersionNumber().startsWith("2")) {
+                    log.error("Hello? " + library);
+                    return true;
+                }
+            }
+
+            return null;
+        });
+
+        if (oldLwjgl != null && oldLwjgl) {
+            log.info("Running with old lwjgl, using xvfb transformer");
+            transformers.add(new XvfbLwjglTransformer());
+        }
+    }
+
 }

headlessmc-launcher/src/main/java/me/earth/headlessmc/launcher/instrumentation/xvfb/XvfbLwjglTransformer.java

@@ -0,0 +1,41 @@
+package me.earth.headlessmc.launcher.instrumentation.xvfb;
+
+import lombok.CustomLog;
+import me.earth.headlessmc.launcher.instrumentation.AbstractClassTransformer;
+import me.earth.headlessmc.launcher.instrumentation.InstrumentationHelper;
+import me.earth.headlessmc.launcher.instrumentation.Target;
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.tree.*;
+
+import java.util.Locale;
+
+@CustomLog
+public class XvfbLwjglTransformer extends AbstractClassTransformer {
+    public XvfbLwjglTransformer() {
+        super("org/lwjgl/opengl/LinuxDisplay");
+    }
+
+    @Override
+    protected void transform(ClassNode cn) {
+        for (MethodNode mn : cn.methods) {
+            if ("getBestDisplayModeExtension".equals(mn.name) && "()I".equals(mn.desc)) {
+                for (AbstractInsnNode insnNode : mn.instructions) {
+                    if (insnNode instanceof IntInsnNode && insnNode.getOpcode() == Opcodes.BIPUSH) {
+                        IntInsnNode intInsnNode = (IntInsnNode) insnNode;
+                        if (intInsnNode.operand == 10) { // private static final int XRANDR = 10;
+                            log.info("Found BI_PUSH XRANDR, replacing with XF86VIDMODE");
+                            intInsnNode.operand = 11; // XF86VIDMODE, idk lets just try this?
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    @Override
+    public boolean matches(Target target) {
+        return target.getPath().toLowerCase(Locale.ENGLISH).contains("lwjgl")
+                && !target.getPath().endsWith(InstrumentationHelper.LWJGL_JAR);
+    }
+
+}

headlessmc-launcher/src/main/java/me/earth/headlessmc/launcher/launch/LaunchOptions.java

@@ -36,6 +36,7 @@ public class LaunchOptions {
     private final boolean inMemory;
     private final boolean forceSimple;
     private final boolean forceBoot;
+    private final boolean xvfb;
     private final boolean prepare;
 
     @SuppressWarnings("unused")
@@ -46,10 +47,12 @@ private LaunchOptionsBuilder() {
 
         public LaunchOptionsBuilder parseFlags(
             Launcher ctx, boolean quit, String... args) {
+            boolean xvfb = false;
             boolean lwjgl = flag(ctx, "-lwjgl", INVERT_LWJGL_FLAG, ALWAYS_LWJGL_FLAG, args);
             // if offline only allow launching with the lwjgl flag!
             if (!lwjgl && launcher.getAccountManager().getOfflineChecker().isOffline()) {
-                if (!new XvfbService(launcher.getConfigService(), launcher.getProcessFactory().getOs()).isRunningWithXvfb()) {
+                xvfb = new XvfbService(launcher.getConfigService(), launcher.getProcessFactory().getOs()).isRunningWithXvfb();
+                if (!xvfb) {
                     log.warning("You are offline, game will start in headless mode!");
                     lwjgl = true;
                 } else {
@@ -68,6 +71,7 @@ public LaunchOptionsBuilder parseFlags(
                 .forceSimple(CommandUtil.hasFlag("-forceSimple", args))
                 .forceBoot(CommandUtil.hasFlag("-forceBoot", args))
                 .parseJvmArgs(args)
+                .xvfb(xvfb)
                 .noIn(quit);
         }
 

headlessmc-launcher/src/test/java/me/earth/headlessmc/launcher/instrumentation/InstrumentationHelperTest.java

@@ -0,0 +1,30 @@
+package me.earth.headlessmc.launcher.instrumentation;
+
+import me.earth.headlessmc.launcher.UsesResources;
+import me.earth.headlessmc.launcher.launch.LaunchOptions;
+import me.earth.headlessmc.launcher.version.ParsesVersions;
+import me.earth.headlessmc.launcher.version.Version;
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class InstrumentationHelperTest implements UsesResources, ParsesVersions {
+    @Test
+    public void testAddXvfbTransformer() {
+        Version version = parseVersion(getJsonObject("version_with_old_lwjgl.json"));
+        LaunchOptions launchOptions = LaunchOptions.builder().version(version).build();
+        List<Transformer> transformers = new ArrayList<>();
+        InstrumentationHelper.addXvfbTransformer(launchOptions, transformers);
+        assertEquals(1, transformers.size());
+
+        version = parseVersion(getJsonObject("version_with_new_lwjgl.json"));
+        launchOptions = LaunchOptions.builder().version(version).build();
+        transformers = new ArrayList<>();
+        InstrumentationHelper.addXvfbTransformer(launchOptions, transformers);
+        assertEquals(0, transformers.size());
+    }
+
+}

headlessmc-launcher/src/test/resources/version_with_new_lwjgl.json

@@ -0,0 +1,20 @@
+{
+  "id": "version-without-parent",
+  "inheritsFrom": "1.18",
+  "releaseTime": "2022-06-17T19:10:29+0000",
+  "time": "2022-06-17T19:10:29+0000",
+  "type": "release",
+  "mainClass": "me.earth.headlessmc.runtime.Main",
+  "arguments": {
+    "game": [],
+    "jvm": [
+      "-DMainClass\u003d net.minecraft.client.main.Main "
+    ]
+  },
+  "libraries": [
+    {
+      "name": "org.lwjgl.lwjgl:lwjgl-platform:3.1.0",
+      "url": "http://lwjgl-url"
+    }
+  ]
+}

headlessmc-launcher/src/test/resources/version_with_old_lwjgl.json

@@ -0,0 +1,20 @@
+{
+  "id": "version-without-parent",
+  "inheritsFrom": "1.18",
+  "releaseTime": "2022-06-17T19:10:29+0000",
+  "time": "2022-06-17T19:10:29+0000",
+  "type": "release",
+  "mainClass": "me.earth.headlessmc.runtime.Main",
+  "arguments": {
+    "game": [],
+    "jvm": [
+      "-DMainClass\u003d net.minecraft.client.main.Main "
+    ]
+  },
+  "libraries": [
+    {
+      "name": "org.lwjgl.lwjgl:lwjgl-platform:2.9.4-nightly-20150209",
+      "url": "http://lwjgl-url"
+    }
+  ]
+}