Add craters (proto-lakes)

worker.js

@@ -78,6 +78,8 @@ ChunkGenerator.prototype.decorate = function(random, chunkX, chunkY, chunkZ, chu
   if (!this.opts.populateTrees) 
     return;
 
+  // trees
+
   // TODO: large-scale biomes, with higher tree density? forests
   var treeCount = ~~scale(this.noiseTrees.noise2D(chunkX / this.opts.treesScale, chunkZ / this.opts.treesScale), -1, 1, 0, this.opts.treesMaxDensity);
 
@@ -111,6 +113,20 @@ ChunkGenerator.prototype.decorate = function(random, chunkX, chunkY, chunkZ, chu
     });
   }
 
+  // "craters" (TODO: fill with water to make lakes)
+  if (random() < 0.20) {
+    var radius = ~~(random() * 10);
+    for (var dx = -radius; dx <= radius; ++dx) {
+      for (var dy = -radius; dy <= radius; ++dy) {
+        for (var dz = -radius; dz <= radius; ++dz) {
+          var distance = Math.sqrt(dx*dx + dy*dy + dz*dz); // TODO: better algorithm
+          if (distance < radius)
+            changes.push([[startX+dx, startY+dy, startZ+dz], 0]);
+        }
+      }
+    }
+  }
+
   return changes;
 };
 
@@ -155,7 +171,7 @@ ChunkGenerator.prototype.generateChunk = function(pos) {
     // features
     var random = new Alea(pos[0] + pos[1] * width + pos[2] * width * width); // TODO: sufficient?
     this.populateChunk(random, pos[0], pos[1], pos[2], heightMap, voxels);
-    changes = this.decorate(random, pos[0], pos[1], pos[2], heightMap);
+    changes = this.decorate(random, pos[0], pos[1], pos[2], heightMap); // TODO: should run in another worker, to not block terrain gen?
   } else if (pos[1] > 0) {
     // empty space above ground
   } else {