move WorldGenerator to world/generator

src/world/generator/WorldGenerator.hpp

@@ -0,0 +1,24 @@
+#pragma once
+
+#include <string>
+
+#include "typedefs.hpp"
+
+struct voxel;
+class Content;
+struct GeneratorDef;
+
+class WorldGenerator {
+    const GeneratorDef& def;
+    const Content* content;
+public:
+    WorldGenerator(
+        const GeneratorDef& def,
+        const Content* content
+    );
+    virtual ~WorldGenerator() = default;
+
+    virtual void generate(voxel* voxels, int x, int z, int seed);
+
+    inline static std::string DEFAULT = "core:default";
+};