de.sanandrew.core.manpack.transformer.TransformBadPotionsATN.java Source code

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Here is the source code for de.sanandrew.core.manpack.transformer.TransformBadPotionsATN.java

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/*******************************************************************************************************************
 * Authors:   SanAndreasP
 * Copyright: SanAndreasP
 * License:   Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International
 *                http://creativecommons.org/licenses/by-nc-sa/4.0/
 *******************************************************************************************************************/
package de.sanandrew.core.manpack.transformer;

import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.Label;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.tree.ClassNode;
import org.objectweb.asm.tree.MethodNode;

import net.minecraft.launchwrapper.IClassTransformer;

public class TransformBadPotionsATN implements IClassTransformer {
    @Override
    public byte[] transform(String name, String transformedName, byte[] bytes) {
        if (transformedName.equals("net.minecraft.potion.Potion")) {
            return this.transformPotion(bytes);
        }

        return bytes;
    }

    private byte[] transformPotion(byte[] bytes) {
        ClassNode cn = ASMHelper.createClassNode(bytes);

        if (ASMHelper.hasClassMethodName(cn, ASMNames.M_isBadEffect)) {
            return bytes;
        }

        MethodNode method = new MethodNode(Opcodes.ACC_PUBLIC, ASMNames.M_isBadEffect, "()Z", null, null);
        method.visitCode();
        Label l0 = new Label();
        method.visitLabel(l0);
        method.visitVarInsn(Opcodes.ALOAD, 0);
        method.visitFieldInsn(Opcodes.GETFIELD, "net/minecraft/potion/Potion", ASMNames.F_isBadEffect, "Z");
        method.visitInsn(Opcodes.IRETURN);
        Label l1 = new Label();
        method.visitLabel(l1);
        method.visitLocalVariable("this", "Lnet/minecraft/potion/Potion;", null, l0, l1, 0);
        method.visitMaxs(0, 0);
        method.visitEnd();

        cn.methods.add(method);

        bytes = ASMHelper.createBytes(cn, ClassWriter.COMPUTE_FRAMES | ClassWriter.COMPUTE_MAXS);

        return bytes;
    }
}