implement new terrain generator, cave generator, tree generator, implement big tree generator, improve light update performance

src/js/net/minecraft/util/MetadataChunkBlock.js

@@ -22,12 +22,18 @@ export default class MetadataChunkBlock {
         if (index > 32768) {
             return;
         }
+
         for (let x = this.x1; x <= this.x2; x++) {
             for (let z = this.z1; z <= this.z2; z++) {
                 if (!world.blockExists(x, 0, z)) {
                     continue;
                 }
 
+                let centerChunk = world.getChunkAt(x >> 4, z >> 4);
+                if (!centerChunk.loaded) {
+                    return;
+                }
+
                 for (let y = this.y1; y <= this.y2; y++) {
                     if (y < 0 || y >= World.TOTAL_HEIGHT) {
                         continue;

src/js/net/minecraft/util/Random.js

@@ -4,15 +4,14 @@ export default class Random {
 
     constructor(seed = Date.now() % 1000000000 ^ Random.instances++ * 1000) {
         this.mask = 0xffffffff;
-        this.m_w = (123456789 + seed) & this.mask;
-        this.m_z = (987654321 - seed) & this.mask;
+        this.setSeed(seed);
     }
 
     nextBoolean() {
         return this.nextFloat() > 0.5;
     }
 
-    nextInt(max) {
+    nextInt(max = 0x7fffffff) {
         return Math.floor(this.nextFloat() * (max + 1));
     }
 
@@ -24,4 +23,10 @@ export default class Random {
         result /= 4294967296;
         return result;
     }
+
+    setSeed(seed) {
+        this.seed = seed;
+        this.m_w = (123456789 + seed) & this.mask;
+        this.m_z = (987654321 - seed) & this.mask;
+    }
 }