Paper/src/main/java/net/minecraft/server/WorldGenMegaTree.java

package net.minecraft.server;

import java.util.Random;

import org.bukkit.BlockChangeDelegate; // CraftBukkit

public class WorldGenMegaTree extends WorldGenerator implements BlockSapling.TreeGenerator { // CraftBukkit add interface

    private final int a;
    private final int b;
    private final int c;

    public WorldGenMegaTree(boolean flag, int i, int j, int k) {
        super(flag);
        this.a = i;
        this.b = j;
        this.c = k;
    }

    public boolean a(World world, Random random, int i, int j, int k) {
        // CraftBukkit start
        return this.generate((BlockChangeDelegate) world, random, i, j, k);
    }

    public boolean generate(BlockChangeDelegate world, Random random, int i, int j, int k) {
        // CraftBukkit end
        int l = random.nextInt(3) + this.a;
        boolean flag = true;

        if (j >= 1 && j + l + 1 <= 256) {
            int i1;
            int j1;
            int k1;
            int l1;

            for (i1 = j; i1 <= j + 1 + l; ++i1) {
                byte b0 = 2;

                if (i1 == j) {
                    b0 = 1;
                }

                if (i1 >= j + 1 + l - 2) {
                    b0 = 2;
                }

                for (j1 = i - b0; j1 <= i + b0 && flag; ++j1) {
                    for (k1 = k - b0; k1 <= k + b0 && flag; ++k1) {
                        if (i1 >= 0 && i1 < 256) {
                            l1 = world.getTypeId(j1, i1, k1);
                            if (l1 != 0 && l1 != Block.LEAVES.id && l1 != Block.GRASS.id && l1 != Block.DIRT.id && l1 != Block.LOG.id && l1 != Block.SAPLING.id) {
                                flag = false;
                            }
                        } else {
                            flag = false;
                        }
                    }
                }
            }

            if (!flag) {
                return false;
            } else {
                i1 = world.getTypeId(i, j - 1, k);
                if ((i1 == Block.GRASS.id || i1 == Block.DIRT.id) && j < 256 - l - 1) {
                    world.setRawTypeId(i, j - 1, k, Block.DIRT.id);
                    world.setRawTypeId(i + 1, j - 1, k, Block.DIRT.id);
                    world.setRawTypeId(i, j - 1, k + 1, Block.DIRT.id);
                    world.setRawTypeId(i + 1, j - 1, k + 1, Block.DIRT.id);
                    this.a(world, i, k, j + l, 2, random);

                    for (int i2 = j + l - 2 - random.nextInt(4); i2 > j + l / 2; i2 -= 2 + random.nextInt(4)) {
                        float f = random.nextFloat() * 3.1415927F * 2.0F;

                        k1 = i + (int) (0.5F + MathHelper.cos(f) * 4.0F);
                        l1 = k + (int) (0.5F + MathHelper.sin(f) * 4.0F);
                        this.a(world, k1, l1, i2, 0, random);

                        for (int j2 = 0; j2 < 5; ++j2) {
                            k1 = i + (int) (1.5F + MathHelper.cos(f) * (float) j2);
                            l1 = k + (int) (1.5F + MathHelper.sin(f) * (float) j2);
                            this.setTypeAndData(world, k1, i2 - 3 + j2 / 2, l1, Block.LOG.id, this.b);
                        }
                    }

                    for (j1 = 0; j1 < l; ++j1) {
                        k1 = world.getTypeId(i, j + j1, k);
                        if (k1 == 0 || k1 == Block.LEAVES.id) {
                            this.setTypeAndData(world, i, j + j1, k, Block.LOG.id, this.b);
                            if (j1 > 0) {
                                if (random.nextInt(3) > 0 && world.isEmpty(i - 1, j + j1, k)) {
                                    this.setTypeAndData(world, i - 1, j + j1, k, Block.VINE.id, 8);
                                }

                                if (random.nextInt(3) > 0 && world.isEmpty(i, j + j1, k - 1)) {
                                    this.setTypeAndData(world, i, j + j1, k - 1, Block.VINE.id, 1);
                                }
                            }
                        }

                        if (j1 < l - 1) {
                            k1 = world.getTypeId(i + 1, j + j1, k);
                            if (k1 == 0 || k1 == Block.LEAVES.id) {
                                this.setTypeAndData(world, i + 1, j + j1, k, Block.LOG.id, this.b);
                                if (j1 > 0) {
                                    if (random.nextInt(3) > 0 && world.isEmpty(i + 2, j + j1, k)) {
                                        this.setTypeAndData(world, i + 2, j + j1, k, Block.VINE.id, 2);
                                    }

                                    if (random.nextInt(3) > 0 && world.isEmpty(i + 1, j + j1, k - 1)) {
                                        this.setTypeAndData(world, i + 1, j + j1, k - 1, Block.VINE.id, 1);
                                    }
                                }
                            }

                            k1 = world.getTypeId(i + 1, j + j1, k + 1);
                            if (k1 == 0 || k1 == Block.LEAVES.id) {
                                this.setTypeAndData(world, i + 1, j + j1, k + 1, Block.LOG.id, this.b);
                                if (j1 > 0) {
                                    if (random.nextInt(3) > 0 && world.isEmpty(i + 2, j + j1, k + 1)) {
                                        this.setTypeAndData(world, i + 2, j + j1, k + 1, Block.VINE.id, 2);
                                    }

                                    if (random.nextInt(3) > 0 && world.isEmpty(i + 1, j + j1, k + 2)) {
                                        this.setTypeAndData(world, i + 1, j + j1, k + 2, Block.VINE.id, 4);
                                    }
                                }
                            }

                            k1 = world.getTypeId(i, j + j1, k + 1);
                            if (k1 == 0 || k1 == Block.LEAVES.id) {
                                this.setTypeAndData(world, i, j + j1, k + 1, Block.LOG.id, this.b);
                                if (j1 > 0) {
                                    if (random.nextInt(3) > 0 && world.isEmpty(i - 1, j + j1, k + 1)) {
                                        this.setTypeAndData(world, i - 1, j + j1, k + 1, Block.VINE.id, 8);
                                    }

                                    if (random.nextInt(3) > 0 && world.isEmpty(i, j + j1, k + 2)) {
                                        this.setTypeAndData(world, i, j + j1, k + 2, Block.VINE.id, 4);
                                    }
                                }
                            }
                        }
                    }

                    return true;
                } else {
                    return false;
                }
            }
        } else {
            return false;
        }
    }

    // CraftBukkit - Changed signature
    private void a(BlockChangeDelegate world, int i, int j, int k, int l, Random random) {
        byte b0 = 2;

        for (int i1 = k - b0; i1 <= k; ++i1) {
            int j1 = i1 - k;
            int k1 = l + 1 - j1;

            for (int l1 = i - k1; l1 <= i + k1 + 1; ++l1) {
                int i2 = l1 - i;

                for (int j2 = j - k1; j2 <= j + k1 + 1; ++j2) {
                    int k2 = j2 - j;

                    if ((i2 >= 0 || k2 >= 0 || i2 * i2 + k2 * k2 <= k1 * k1) && (i2 <= 0 && k2 <= 0 || i2 * i2 + k2 * k2 <= (k1 + 1) * (k1 + 1)) && (random.nextInt(4) != 0 || i2 * i2 + k2 * k2 <= (k1 - 1) * (k1 - 1)) && !Block.n[world.getTypeId(l1, i1, j2)]) {
                        this.setTypeAndData(world, l1, i1, j2, Block.LEAVES.id, this.c);
                    }
                }
            }
        }
    }
}