ModelLoadingMixinPlugin.java

package me.modmuss50.optifabric.compat.fabricmodelloadingapi;

import me.modmuss50.optifabric.compat.InterceptingMixinPlugin;
import me.modmuss50.optifabric.util.MixinUtils;
import me.modmuss50.optifabric.util.RemappingUtils;
import net.fabricmc.tinyremapper.IMappingProvider.Member;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.tree.*;
import org.spongepowered.asm.mixin.extensibility.IMixinInfo;
import org.spongepowered.asm.mixin.transformer.ClassInfo;

public class ModelLoadingMixinPlugin extends InterceptingMixinPlugin {
    @Override
    public void preApply(String targetClassName, ClassNode targetClass, String mixinClassName, IMixinInfo mixinInfo) {
        // not doing this will cause Mixin to have a stroke while trying to find where to put the fabric injectors
        ClassInfo info = ClassInfo.forName(targetClassName);
        MixinUtils.completeClassInfo(info, targetClass.methods);
        String bakeDesc = "(Lnet/minecraft/class_2960;Lnet/minecraft/class_3665;)Lnet/minecraft/class_1087;";//(Identifier, ModelBakeSettings)BakedModel
        String bake = RemappingUtils.getMethodName("class_7775", "method_45873", bakeDesc);//BakerImpl, bake
        bakeDesc = RemappingUtils.mapMethodDescriptor(bakeDesc);
        if ("ModelLoaderBakerImplMixin".equals(mixinInfo.getName())) {
            for (MethodNode method : targetClass.methods) {
                if (bake.equals(method.name) && bakeDesc.equals(method.desc)) {
                    //This is the @ModifyVariable
                    //target = "Lnet/minecraft/client/render/model/ModelLoader$BakerImpl;getOrLoadModel(Lnet/minecraft/util/Identifier;)Lnet/minecraft/client/render/model/UnbakedModel;"
                    Member mfMixinTarget = RemappingUtils.mapMethod("class_1088$class_7778", "method_45872", "(Lnet/minecraft/class_2960;)Lnet/minecraft/class_1100;");
                    LabelNode fakeStart = new LabelNode();
                    LabelNode skip = new LabelNode();
                    InsnList extraFirst = new InsnList();

                    /*
                    The following line doesn't work because why would it work (it does in OriginMixinPlugin)
                    so I have to resort to using postApply and remove this trash code
                     */
//                    extra.add(new JumpInsnNode(Opcodes.GOTO, skip));
                    extraFirst.add(fakeStart);
                    extraFirst.add(new InsnNode(Opcodes.ACONST_NULL));
                    extraFirst.add(new InsnNode(Opcodes.ACONST_NULL));
                    extraFirst.add(new MethodInsnNode(Opcodes.INVOKEVIRTUAL, mfMixinTarget.owner, mfMixinTarget.name, mfMixinTarget.desc));
                    extraFirst.add(new VarInsnNode(Opcodes.ASTORE, 3));
                    extraFirst.add(skip);

                    method.localVariables.add(new LocalVariableNode("fakeUnbakedModel", "L" + RemappingUtils.getClassName("class_1087") + ";", null, fakeStart, skip, 3));
                    method.instructions.insertBefore(method.instructions.getFirst(), extraFirst);
                    method.maxLocals += 1;

                    //This part takes care of the two @Redirect
                    //target = "Lnet/minecraft/client/render/model/UnbakedModel;bake(Lnet/minecraft/client/render/model/Baker;Ljava/util/function/Function;Lnet/minecraft/client/render/model/ModelBakeSettings;Lnet/minecraft/util/Identifier;)Lnet/minecraft/client/render/model/BakedModel;"
                    Member redirectMixinTarget1 = RemappingUtils.mapMethod("class_1100", "method_4753", "(Lnet/minecraft/class_7775;Ljava/util/function/Function;Lnet/minecraft/class_3665;Lnet/minecraft/class_2960;)Lnet/minecraft/class_1087;");
                    //target = "Lnet/minecraft/client/render/model/json/JsonUnbakedModel;bake(Lnet/minecraft/client/render/model/Baker;Lnet/minecraft/client/render/model/json/JsonUnbakedModel;Ljava/util/function/Function;Lnet/minecraft/client/render/model/ModelBakeSettings;Lnet/minecraft/util/Identifier;Z)Lnet/minecraft/client/render/model/BakedModel;"
                    Member redirectMixinTarget2 = RemappingUtils.mapMethod("class_793", "method_3446", "(Lnet/minecraft/class_7775;Lnet/minecraft/class_793;Ljava/util/function/Function;Lnet/minecraft/class_3665;Lnet/minecraft/class_2960;Z)Lnet/minecraft/class_1087;");
                    LabelNode skipLast = new LabelNode();
                    InsnList extraLast = new InsnList();
                    // this works because funny (and because no local variable is involved)
                    extraLast.add(new JumpInsnNode(Opcodes.GOTO, skipLast));
                    extraLast.add(new MethodInsnNode(Opcodes.INVOKEINTERFACE, redirectMixinTarget1.owner, redirectMixinTarget1.name, redirectMixinTarget1.desc));
                    extraLast.add(new MethodInsnNode(Opcodes.INVOKEINTERFACE, redirectMixinTarget2.owner, redirectMixinTarget2.name, redirectMixinTarget2.desc));
                    extraLast.add(skipLast);
                    method.instructions.insertBefore(method.instructions.getLast(), extraLast);
                    break;
                }
            }
        }

        super.preApply(targetClassName, targetClass, mixinClassName, mixinInfo);
    }

    @Override
    public void postApply(String targetClassName, ClassNode targetClass, String mixinClassName, IMixinInfo mixinInfo) {
        String bakeDesc = "(Lnet/minecraft/class_2960;Lnet/minecraft/class_3665;)Lnet/minecraft/class_1087;";
        String bake = RemappingUtils.getMethodName("class_7775", "method_45873", bakeDesc);
        bakeDesc = RemappingUtils.mapMethodDescriptor(bakeDesc);

        if ("ModelLoaderBakerImplMixin".equals(mixinInfo.getName())) {
            out: for (MethodNode method : targetClass.methods) {
                if (bake.equals(method.name) && bakeDesc.equals(method.desc)) {
                    LocalVariableNode fakeUnbakedModel = method.localVariables.get(3);
                    method.localVariables.remove(fakeUnbakedModel);
                    method.maxLocals -= 1;
                    // remove trash
                    for (AbstractInsnNode insn : method.instructions) {
                        method.instructions.remove(insn);
                        System.out.println(insn);
                        if (fakeUnbakedModel.end.equals(insn)) {
                            break out;
                        }
                    }
                }
            }
        }
        super.postApply(targetClassName, targetClass, mixinClassName, mixinInfo);
    }
}