Code/net/minecraft/world/phys/shapes/NonOverlappingMerger.java

package net.minecraft.world.phys.shapes;

import it.unimi.dsi.fastutil.doubles.AbstractDoubleList;
import it.unimi.dsi.fastutil.doubles.DoubleList;

public class NonOverlappingMerger extends AbstractDoubleList implements IndexMerger {
    private final DoubleList lower;
    private final DoubleList upper;
    private final boolean swap;

    protected NonOverlappingMerger(DoubleList p_83012_, DoubleList p_83013_, boolean p_83014_) {
        this.lower = p_83012_;
        this.upper = p_83013_;
        this.swap = p_83014_;
    }

    @Override
    public int size() {
        return this.lower.size() + this.upper.size();
    }

    @Override
    public boolean forMergedIndexes(IndexMerger.IndexConsumer p_83017_) {
        return this.swap ? this.forNonSwappedIndexes((p_83020_, p_83021_, p_83022_) -> p_83017_.merge(p_83021_, p_83020_, p_83022_)) : this.forNonSwappedIndexes(p_83017_);
    }

    private boolean forNonSwappedIndexes(IndexMerger.IndexConsumer p_83024_) {
        int i = this.lower.size();

        for (int j = 0; j < i; j++) {
            if (!p_83024_.merge(j, -1, j)) {
                return false;
            }
        }

        int l = this.upper.size() - 1;

        for (int k = 0; k < l; k++) {
            if (!p_83024_.merge(i - 1, k, i + k)) {
                return false;
            }
        }

        return true;
    }

    @Override
    public double getDouble(int p_83026_) {
        return p_83026_ < this.lower.size() ? this.lower.getDouble(p_83026_) : this.upper.getDouble(p_83026_ - this.lower.size());
    }

    @Override
    public DoubleList getList() {
        return this;
    }
}