Added WorldGenSwampTree for diff visibility

src/main/java/net/minecraft/server/WorldGenSwampTree.java

@@ -0,0 +1,138 @@
+package net.minecraft.server;
+
+import java.util.Random;
+
+public class WorldGenSwampTree extends WorldGenerator {
+
+    public WorldGenSwampTree() {}
+
+    public boolean a(World world, Random random, int i, int j, int k) {
+        int l;
+
+        for (l = random.nextInt(4) + 5; world.getMaterial(i, j - 1, k) == Material.WATER; --j) {
+            ;
+        }
+
+        boolean flag = true;
+
+        if (j >= 1 && j + l + 1 <= 128) {
+            int i1;
+            int j1;
+            int k1;
+            int l1;
+
+            for (i1 = j; i1 <= j + 1 + l; ++i1) {
+                byte b0 = 1;
+
+                if (i1 == j) {
+                    b0 = 0;
+                }
+
+                if (i1 >= j + 1 + l - 2) {
+                    b0 = 3;
+                }
+
+                for (j1 = i - b0; j1 <= i + b0 && flag; ++j1) {
+                    for (k1 = k - b0; k1 <= k + b0 && flag; ++k1) {
+                        if (i1 >= 0 && i1 < 128) {
+                            l1 = world.getTypeId(j1, i1, k1);
+                            if (l1 != 0 && l1 != Block.LEAVES.id) {
+                                if (l1 != Block.STATIONARY_WATER.id && l1 != Block.WATER.id) {
+                                    flag = false;
+                                } else if (i1 > j) {
+                                    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 < 128 - l - 1) {
+                    world.setRawTypeId(i, j - 1, k, Block.DIRT.id);
+
+                    int i2;
+                    int j2;
+
+                    for (j2 = j - 3 + l; j2 <= j + l; ++j2) {
+                        j1 = j2 - (j + l);
+                        k1 = 2 - j1 / 2;
+
+                        for (l1 = i - k1; l1 <= i + k1; ++l1) {
+                            i2 = l1 - i;
+
+                            for (int k2 = k - k1; k2 <= k + k1; ++k2) {
+                                int l2 = k2 - k;
+
+                                if ((Math.abs(i2) != k1 || Math.abs(l2) != k1 || random.nextInt(2) != 0 && j1 != 0) && !Block.n[world.getTypeId(l1, j2, k2)]) {
+                                    world.setRawTypeId(l1, j2, k2, Block.LEAVES.id);
+                                }
+                            }
+                        }
+                    }
+
+                    for (j2 = 0; j2 < l; ++j2) {
+                        j1 = world.getTypeId(i, j + j2, k);
+                        if (j1 == 0 || j1 == Block.LEAVES.id || j1 == Block.WATER.id || j1 == Block.STATIONARY_WATER.id) {
+                            world.setRawTypeId(i, j + j2, k, Block.LOG.id);
+                        }
+                    }
+
+                    for (j2 = j - 3 + l; j2 <= j + l; ++j2) {
+                        j1 = j2 - (j + l);
+                        k1 = 2 - j1 / 2;
+
+                        for (l1 = i - k1; l1 <= i + k1; ++l1) {
+                            for (i2 = k - k1; i2 <= k + k1; ++i2) {
+                                if (world.getTypeId(l1, j2, i2) == Block.LEAVES.id) {
+                                    if (random.nextInt(4) == 0 && world.getTypeId(l1 - 1, j2, i2) == 0) {
+                                        this.a(world, l1 - 1, j2, i2, 8);
+                                    }
+
+                                    if (random.nextInt(4) == 0 && world.getTypeId(l1 + 1, j2, i2) == 0) {
+                                        this.a(world, l1 + 1, j2, i2, 2);
+                                    }
+
+                                    if (random.nextInt(4) == 0 && world.getTypeId(l1, j2, i2 - 1) == 0) {
+                                        this.a(world, l1, j2, i2 - 1, 1);
+                                    }
+
+                                    if (random.nextInt(4) == 0 && world.getTypeId(l1, j2, i2 + 1) == 0) {
+                                        this.a(world, l1, j2, i2 + 1, 4);
+                                    }
+                                }
+                            }
+                        }
+                    }
+
+                    return true;
+                } else {
+                    return false;
+                }
+            }
+        } else {
+            return false;
+        }
+    }
+
+    private void a(World world, int i, int j, int k, int l) {
+        world.setTypeIdAndData(i, j, k, Block.VINE.id, l);
+        int i1 = 4;
+
+        while (true) {
+            --j;
+            if (world.getTypeId(i, j, k) != 0 || i1 <= 0) {
+                return;
+            }
+
+            world.setTypeIdAndData(i, j, k, Block.VINE.id, l);
+            --i1;
+        }
+    }
+}