Reading minecraft source code

[Skrallbadoor]

Hello there,

 

I'm modding a bit for a while now and I saw in a few tutorials that some people can read the code of the files in "Referenced Libaries" in Eclipse, what'd make modding way easier for me.

Sadly, it isn't the case for me, the only informations I get when I'm trying to open the files are:

"Class File Editor"

"Source not found"

"The JAR file C:\Users\Skrallbadoor\.gradle\cache\forge_gradle_minecraft:user_repo\net\minecraft......................\1.14.2.jar has no source attachment"

"You can attach the source by clicking Attach Source below:"

[Attach Source...]

and then code like:

/ Compiled from ItemEntity.java (version 1.8 : 52.0, super bit)
public class net.minecraft.entity.item.ItemEntity extends net.minecraft.entity.Entity {
  
  // Field descriptor #12 Lnet/minecraft/network/datasync/DataParameter;
  // Signature: Lnet/minecraft/network/datasync/DataParameter<Lnet/minecraft/item/ItemStack;>;
  private static final net.minecraft.network.datasync.DataParameter ITEM;
  
  // Field descriptor #15 I
  private int age;
  
  // Field descriptor #15 I
  private int pickupDelay;
  
  // Field descriptor #15 I
  private int health;
  
  // Field descriptor #19 Ljava/util/UUID;
  private java.util.UUID thrower;
  
  // Field descriptor #19 Ljava/util/UUID;
  private java.util.UUID owner;
  
  // Field descriptor #15 I
  public int lifespan;
  
  // Field descriptor #23 F
  public final float hoverStart;
  
  // Method descriptor #25 (Lnet/minecraft/entity/EntityType;Lnet/minecraft/world/World;)V
  // Signature: (Lnet/minecraft/entity/EntityType<+Lnet/minecraft/entity/item/ItemEntity;>;Lnet/minecraft/world/World;)V
  // Stack: 5, Locals: 3
  public ItemEntity(net.minecraft.entity.EntityType p_i50217_1_, net.minecraft.world.World p_i50217_2_);
     0  aload_0 [this]
     1  aload_1 [p_i50217_1_]
     2  aload_2 [p_i50217_2_]
     3  invokespecial net.minecraft.entity.Entity(net.minecraft.entity.EntityType, net.minecraft.world.World) [28]
     6  aload_0 [this]
     7  iconst_5
     8  putfield net.minecraft.entity.item.ItemEntity.health : int [30]
    11  aload_0 [this]
    12  sipush 6000
    15  putfield net.minecraft.entity.item.ItemEntity.lifespan : int [32]
    18  aload_0 [this]
    19  invokestatic java.lang.Math.random() : double [38]
    22  ldc2_w <Double 3.141592653589793> [39]
    25  dmul
    26  ldc2_w <Double 2.0> [41]
    29  dmul
    30  d2f
    31  putfield net.minecraft.entity.item.ItemEntity.hoverStart : float [44]
    34  return
      Line numbers:
        [pc: 0, line: 48]
        [pc: 6, line: 38]
        [pc: 11, line: 44]
        [pc: 18, line: 45]
        [pc: 34, line: 49]
      Local variable table:
        [pc: 0, pc: 35] local: this index: 0 type: net.minecraft.entity.item.ItemEntity
        [pc: 0, pc: 35] local: p_i50217_1_ index: 1 type: net.minecraft.entity.EntityType
        [pc: 0, pc: 35] local: p_i50217_2_ index: 2 type: net.minecraft.world.World
      Local variable type table:
        [pc: 0, pc: 35] local: p_i50217_1_ index: 1 type: net.minecraft.entity.EntityType<? extends net.minecraft.entity.item.ItemEntity>
  
  // Method descriptor #52 (Lnet/minecraft/world/World;DDD)V
  // Stack: 9, Locals: 8
  public ItemEntity(net.minecraft.world.World p_i1709_1_, double p_i1709_2_, double p_i1709_4_, double p_i1709_6_);
     0  aload_0 [this]
     1  getstatic net.minecraft.entity.EntityType.ITEM : net.minecraft.entity.EntityType [56]
     4  aload_1 [p_i1709_1_]
     5  invokespecial net.minecraft.entity.item.ItemEntity(net.minecraft.entity.EntityType, net.minecraft.world.World) [57]
     8  aload_0 [this]
     9  dload_2 [p_i1709_2_]
    10  dload 4 [p_i1709_4_]
    12  dload 6 [p_i1709_6_]
    14  invokevirtual net.minecraft.entity.item.ItemEntity.setPosition(double, double, double) : void [61]
    17  aload_0 [this]
    18  aload_0 [this]
    19  getfield net.minecraft.entity.item.ItemEntity.rand : java.util.Random [65]
    22  invokevirtual java.util.Random.nextFloat() : float [71]
    25  ldc <Float 360.0> [72]
    27  fmul
    28  putfield net.minecraft.entity.item.ItemEntity.rotationYaw : float [75]
    31  aload_0 [this]
    32  aload_0 [this]
    33  getfield net.minecraft.entity.item.ItemEntity.rand : java.util.Random [65]
    36  invokevirtual java.util.Random.nextDouble() : double [78]
    39  ldc2_w <Double 0.2> [79]
    42  dmul
    43  ldc2_w <Double 0.1> [81]
    46  dsub
    47  ldc2_w <Double 0.2> [79]
    50  aload_0 [this]
    51  getfield net.minecraft.entity.item.ItemEntity.rand : java.util.Random [65]
    54  invokevirtual java.util.Random.nextDouble() : double [78]
    57  ldc2_w <Double 0.2> [79]
    60  dmul
    61  ldc2_w <Double 0.1> [81]
    64  dsub
    65  invokevirtual net.minecraft.entity.item.ItemEntity.setMotion(double, double, double) : void [85]
    68  return
      Line numbers:
        [pc: 0, line: 52]
        [pc: 8, line: 53]
        [pc: 17, line: 54]
        [pc: 31, line: 55]
        [pc: 68, line: 56]
      Local variable table:
        [pc: 0, pc: 69] local: this index: 0 type: net.minecraft.entity.item.ItemEntity
        [pc: 0, pc: 69] local: p_i1709_1_ index: 1 type: net.minecraft.world.World
        [pc: 0, pc: 69] local: p_i1709_2_ index: 2 type: double
        [pc: 0, pc: 69] local: p_i1709_4_ index: 4 type: double
        [pc: 0, pc: 69] local: p_i1709_6_ index: 6 type: double
  
  // Method descriptor #91 (Lnet/minecraft/world/World;DDDLnet/minecraft/item/ItemStack;)V
  // Stack: 8, Locals: 9
  public ItemEntity(net.minecraft.world.World p_i1710_1_, double p_i1710_2_, double p_i1710_4_, double p_i1710_6_, net.minecraft.item.ItemStack p_i1710_8_);
     0  aload_0 [this]
     1  aload_1 [p_i1710_1_]
     2  dload_2 [p_i1710_2_]
     3  dload 4 [p_i1710_4_]
     5  dload 6 [p_i1710_6_]
     7  invokespecial net.minecraft.entity.item.ItemEntity(net.minecraft.world.World, double, double, double) [93]
    10  aload_0 [this]
    11  aload 8 [p_i1710_8_]
    13  invokevirtual net.minecraft.entity.item.ItemEntity.setItem(net.minecraft.item.ItemStack) : void [97]
    16  aload_0 [this]
    17  aload 8 [p_i1710_8_]
    19  invokevirtual net.minecraft.item.ItemStack.getItem() : net.minecraft.item.Item [103]
    22  ifnonnull 31
    25  sipush 6000
    28  goto 37
    31  aload 8 [p_i1710_8_]
    33  aload_1 [p_i1710_1_]
    34  invokevirtual net.minecraft.item.ItemStack.getEntityLifespan(net.minecraft.world.World) : int [109]
    37  putfield net.minecraft.entity.item.ItemEntity.lifespan : int [32]
    40  return
      Line numbers:
        [pc: 0, line: 59]
        [pc: 10, line: 60]
        [pc: 16, line: 61]
        [pc: 40, line: 62]
      Local variable table:
        [pc: 0, pc: 41] local: this index: 0 type: net.minecraft.entity.item.ItemEntity
        [pc: 0, pc: 41] local: p_i1710_1_ index: 1 type: net.minecraft.world.World
        [pc: 0, pc: 41] local: p_i1710_2_ index: 2 type: double
        [pc: 0, pc: 41] local: p_i1710_4_ index: 4 type: double
        [pc: 0, pc: 41] local: p_i1710_6_ index: 6 type: double
        [pc: 0, pc: 41] local: p_i1710_8_ index: 8 type: net.minecraft.item.ItemStack
      Stack map table: number of frames 2
        [pc: 31, full, stack: {net.minecraft.entity.item.ItemEntity}, locals: {net.minecraft.entity.item.ItemEntity, net.minecraft.world.World, double, double, double, net.minecraft.item.ItemStack}]
        [pc: 37, full, stack: {net.minecraft.entity.item.ItemEntity, int}, locals: {net.minecraft.entity.item.ItemEntity, net.minecraft.world.World, double, double, double, net.minecraft.item.ItemStack}]
  
  // Method descriptor #117 ()Z
  // Stack: 1, Locals: 1
  protected boolean canTriggerWalking();
    0  iconst_0
    1  ireturn
      Line numbers:
        [pc: 0, line: 65]
      Local variable table:
        [pc: 0, pc: 2] local: this index: 0 type: net.minecraft.entity.item.ItemEntity
  
  // Method descriptor #119 ()V
  // Stack: 3, Locals: 1
  protected void registerData();
     0  aload_0 [this]
     1  invokevirtual net.minecraft.entity.item.ItemEntity.getDataManager() : net.minecraft.network.datasync.EntityDataManager [123]
     4  getstatic net.minecraft.entity.item.ItemEntity.ITEM : net.minecraft.network.datasync.DataParameter [125]
     7  getstatic net.minecraft.item.ItemStack.EMPTY : net.minecraft.item.ItemStack [128]
    10  invokevirtual net.minecraft.network.datasync.EntityDataManager.register(net.minecraft.network.datasync.DataParameter, java.lang.Object) : void [134]
    13  return
      Line numbers:
        [pc: 0, line: 69]
        [pc: 13, line: 70]
      Local variable table:
        [pc: 0, pc: 14] local: this index: 0 type: net.minecraft.entity.item.ItemEntity
  
  // Method descriptor #119 ()V
  // Stack: 8, Locals: 6
  public void tick();
      0  aload_0 [this]
      1  invokevirtual net.minecraft.entity.item.ItemEntity.getItem() : net.minecraft.item.ItemStack [138]
      4  aload_0 [this]
      5  invokevirtual net.minecraft.item.ItemStack.onEntityItemUpdate(net.minecraft.entity.item.ItemEntity) : boolean [142]
      8  ifeq 12
     11  return
     12  aload_0 [this]
     13  invokevirtual net.minecraft.entity.item.ItemEntity.getItem() : net.minecraft.item.ItemStack [138]
     16  invokevirtual net.minecraft.item.ItemStack.isEmpty() : boolean [145]
     19  ifeq 29
     22  aload_0 [this]

 

On the right side, I have an Outline Window where I can see method and variable names, but thoses aren't what I'm searching for.

 

Well, now to my question, is there a way to open the jsons in Referenced Libs. and is there a way to get the decompiled code of the class files?

I tried to copy and paste the files, what didint work, that way I can't put the class files into a decompiler. I opened the path where the files are then, and put the class files into a decompiler, but I only got "field_number_letter"s and "function_number_letters"s as code.

 

I've heard something about a MCP(Minecraft Coder Pack). I'm not sure if I need this to solve my problems and if yes, how to use/install MCP.

[PhilipChonacky]

For many of the non-Minecraft libraries, there is no source code.

Minecraft source code in all in the Minecraft Forge library(ies) which usually are at the top of the list of referenced libraries in Eclipse.

 

MCP maps the deobfuscation of the Minecraft source code and is applied through Gradle directives.  There are stable and daily exports depending on which version of MC you are working with.  To update MCP mappings, edit the 'build.gradle' file and re-run gradlew.

 

Hope this helps.

/P

[DaemonUmbra]

You should NEVER use MCP directly.