sneak clutch fix

ServerPlayNetworkHandlerMixin.java

package dev.tildejustin.xrayfix.mixin;

import com.llamalad7.mixinextras.sugar.*;
import com.llamalad7.mixinextras.sugar.ref.LocalRef;
import dev.tildejustin.xrayfix.mixin.accessor.EntityAccessor;
import net.minecraft.server.network.*;
import net.minecraft.util.math.*;
import org.spongepowered.asm.mixin.*;
import org.spongepowered.asm.mixin.injection.*;

@Mixin(ServerPlayNetworkHandler.class)
public abstract class ServerPlayNetworkHandlerMixin {
    @Shadow
    public ServerPlayerEntity player;

    @ModifyArg(method = "onPlayerMove", at = @At(value = "INVOKE", target = "Lnet/minecraft/server/network/ServerPlayerEntity;move(Lnet/minecraft/entity/MovementType;Lnet/minecraft/util/math/Vec3d;)V"))
    private Vec3d captureTargetMovementVector(Vec3d original, @Share("x") LocalRef<Double> sharedX, @Share("z") LocalRef<Double> sharedZ) {
        sharedX.set(this.player.getX());
        sharedZ.set(this.player.getZ());

        // calculates the player x & z position that would be set by Player#move if the player wasn't sneaking
        Vec3d movement = original, movementMultiplier = ((EntityAccessor) this.player).getMovementMultiplier();
        if (movementMultiplier.lengthSquared() > 1e-7) {
            movement = movement.multiply(movementMultiplier);
        }
        /* movement = this.adjustMovementForSneaking(movement, type); */
        Vec3d vec3d = ((EntityAccessor) this.player).callAdjustMovementForCollisions(movement);
        if (vec3d.lengthSquared() > 1e-7) {
            Box box = this.player.getBoundingBox().offset(vec3d);
            // Entity#moveToBoundingBoxCenter
            sharedX.set((box.minX + box.maxX) / 2);
            sharedZ.set((box.minZ + box.maxZ) / 2);
        }

        return original;
    }

    @ModifyVariable(
            method = "onPlayerMove",
            at = @At(value = "LOAD"),
            ordinal = 11,
            slice = @Slice(from = @At(value = "INVOKE", target = "Lnet/minecraft/server/network/ServerPlayerEntity;move(Lnet/minecraft/entity/MovementType;Lnet/minecraft/util/math/Vec3d;)V"))
    )
    private double qAfterMove(
            double original,
            @Local(ordinal = 4) double h,
            @Local(ordinal = 6) double j,
            @Local(ordinal = 8) double n,
            @Share("x") LocalRef<Double> sharedX,
            @Share("z") LocalRef<Double> sharedZ) {
        if (original <= 0.0625) return original;
        if (player.noClip) return original;
        if (!this.player.isSneaking() || this.player.isOnGround()) return original;

        double x = sharedX.get(), z = sharedZ.get();
        double q = (h - x) * (h - x) * n * n * (j - z) * (j - z);
        System.out.println("Would have warped back when sneaking, trying movement without sneaking: " + q);
        return q;
    }
}