uk.co.mysterymayhem.tessellatorfix.Transformer.java Source code

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Here is the source code for uk.co.mysterymayhem.tessellatorfix.Transformer.java

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/*
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package uk.co.mysterymayhem.tessellatorfix;

import java.util.Iterator;
import net.minecraft.launchwrapper.IClassTransformer;
import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.tree.ClassNode;
import org.objectweb.asm.tree.FieldInsnNode;
import org.objectweb.asm.tree.InsnList;
import org.objectweb.asm.tree.InsnNode;
import org.objectweb.asm.tree.JumpInsnNode;
import org.objectweb.asm.tree.LabelNode;
import org.objectweb.asm.tree.MethodNode;
import org.objectweb.asm.tree.VarInsnNode;
import cpw.mods.fml.common.FMLLog;

/**
 *
 * @author Thomas
 */
public class Transformer implements IClassTransformer {

    private static final String CLASS_NAME = "net.minecraft.client.renderer.Tessellator";

    //  private int rawBufferIndex  = 0;
    //  private double xOffset = 0;
    //  private double yOffset = 0;
    //  private double zOffset = 0;
    //  private int[] rawBuffer = null;
    //  private int vertexCount = 0;
    //  private boolean hasTexture = false;
    //  private boolean hasBrightness = false;
    //  private boolean hasNormals = false;
    //  private boolean hasColor = false;

    @Override
    public byte[] transform(String className, String transformedClassName, byte[] bytes) {

        if (bytes == null) {
            return null;
        }

        if (transformedClassName.equals(CLASS_NAME)) {
            return patchTessellatorClass(bytes);
        }

        return bytes;
    }

    private static byte[] patchTessellatorClass(byte[] bytes) {
        String targetMethodName;

        if (Plugin.runtimeDeobfEnabled) {
            targetMethodName = "func_147564_a";
        } else {
            targetMethodName = "getVertexState";
        }

        ClassNode classNode = new ClassNode();
        ClassReader classReader = new ClassReader(bytes);
        classReader.accept(classNode, 0);

        Iterator<MethodNode> methods = classNode.methods.iterator();
        while (methods.hasNext()) {
            MethodNode m = methods.next();
            if ((m.name.equals(targetMethodName)
                    && m.desc.equals("(FFF)Lnet/minecraft/client/shader/TesselatorVertexState;"))) {
                FMLLog.info("Inside target Tessellator method");

                InsnList toInject = new InsnList();

                // Insertion of "if (this.rawBufferIndex < 1) return"
                LabelNode labelNode = new LabelNode();

                toInject.add(new VarInsnNode(Opcodes.ALOAD, 0));
                String fieldName;
                if (Plugin.runtimeDeobfEnabled) {
                    fieldName = "field_147569_p";
                } else {
                    fieldName = "rawBufferIndex";
                }
                toInject.add(new FieldInsnNode(Opcodes.GETFIELD, "net/minecraft/client/renderer/Tessellator",
                        fieldName, "I"));
                toInject.add(new InsnNode(Opcodes.ICONST_1));
                toInject.add(new JumpInsnNode(Opcodes.IF_ICMPGE, labelNode));
                toInject.add(new InsnNode(Opcodes.ACONST_NULL));
                toInject.add(new InsnNode(Opcodes.ARETURN));
                toInject.add(labelNode);

                // Insert after
                m.instructions.insert(toInject);

                ClassWriter writer = new ClassWriter(ClassWriter.COMPUTE_MAXS | ClassWriter.COMPUTE_FRAMES);
                classNode.accept(writer);
                FMLLog.info("Exiting target Tessellator method");
                return writer.toByteArray();
            }
        }

        FMLLog.warning("Could not find Tessellator method out of:");
        StringBuilder builder = new StringBuilder();
        for (MethodNode methodNode : classNode.methods) {
            builder.append(methodNode.name).append(":").append(methodNode.desc).append("\n");
        }
        FMLLog.info(builder.toString());

        return bytes;
    }

    //  // Used to work out the correct bytecode to insert
    //  
    //  public TesselatorVertexState getVertexState(float p_147564_1_, float p_147564_2_, float p_147564_3_)
    //    {
    //        int[] aint = new int[this.rawBufferIndex];
    //        PriorityQueue priorityqueue = new PriorityQueue(this.rawBufferIndex, new QuadComparator(this.rawBuffer, p_147564_1_ + (float)this.xOffset, p_147564_2_ + (float)this.yOffset, p_147564_3_ + (float)this.zOffset));
    //        byte b0 = 32;
    //        int i;
    //
    //        for (i = 0; i < this.rawBufferIndex; i += b0)
    //        {
    //            priorityqueue.add(Integer.valueOf(i));
    //        }
    //
    //        for (i = 0; !priorityqueue.isEmpty(); i += b0)
    //        {
    //            int j = ((Integer)priorityqueue.remove()).intValue();
    //
    //            for (int k = 0; k < b0; ++k)
    //            {
    //                aint[i + k] = this.rawBuffer[j + k];
    //            }
    //        }
    //
    //        System.arraycopy(aint, 0, this.rawBuffer, 0, aint.length);
    //        return new TesselatorVertexState(aint, this.rawBufferIndex, this.vertexCount, this.hasTexture, this.hasBrightness, this.hasNormals, this.hasColor);
    //    }
    //  
    //  public TesselatorVertexState getVertexStatePatched(float p_147564_1_, float p_147564_2_, float p_147564_3_)
    //    {
    //        if(this.rawBufferIndex < 1) return null;
    //        int[] aint = new int[this.rawBufferIndex];
    //        PriorityQueue priorityqueue = new PriorityQueue(this.rawBufferIndex, new QuadComparator(this.rawBuffer, p_147564_1_ + (float)this.xOffset, p_147564_2_ + (float)this.yOffset, p_147564_3_ + (float)this.zOffset));
    //        byte b0 = 32;
    //        int i;
    //
    //        for (i = 0; i < this.rawBufferIndex; i += b0)
    //        {
    //            priorityqueue.add(Integer.valueOf(i));
    //        }
    //
    //        for (i = 0; !priorityqueue.isEmpty(); i += b0)
    //        {
    //            int j = ((Integer)priorityqueue.remove()).intValue();
    //
    //            for (int k = 0; k < b0; ++k)
    //            {
    //                aint[i + k] = this.rawBuffer[j + k];
    //            }
    //        }
    //
    //        System.arraycopy(aint, 0, this.rawBuffer, 0, aint.length);
    //        return new TesselatorVertexState(aint, this.rawBufferIndex, this.vertexCount, this.hasTexture, this.hasBrightness, this.hasNormals, this.hasColor);
    //    }

}