Block.h

#pragma once
//#define USE_BOOST 1

#include "DXUT.h"

#ifdef USE_BOOST
#include <boost/unordered_map.hpp>
#define hash_t boost::hash
#define unordered_map_t boost::unordered_map
#else
#include <unordered_map>
#define hash_t std::tr1::hash
#define unordered_map_t std::tr1::unordered_map
#endif

#include <functional>
#include <queue>

struct BLOCK_ID {
  BLOCK_ID(void) : x(0), y(0), z(0) {}
  BLOCK_ID(int x, int y, int z) : x(x), y(y), z(z) {}

  int x, y, z;
};

size_t hash_t<BLOCK_ID>::operator ()(const BLOCK_ID &id) const {
  return ((static_cast<size_t>(id.y) & 0x0FF) << 24) |
         ((static_cast<size_t>(id.x) & 0xFFF) << 12) |
         ((static_cast<size_t>(id.z) & 0xFFF) <<  0);
}

bool std::equal_to<BLOCK_ID>::operator ()(const BLOCK_ID &left, const BLOCK_ID &right) const {
  return left.x == right.x && left.y == right.y && left.z == right.z;
}

class Block {
 public:
  void Activate(void);
  void Deactivate(void);

  void Draw(ID3D10Device *device, ID3D10EffectTechnique *technique);
  bool empty(void) const { return primitive_count_ == 0 || index_count_ == 0; }

  const BLOCK_ID &id(void) const { return id_; }
  bool active(void) const { return active_; }
  bool used(void) const { return used_; }
  void set_used(bool used) { used_ = used; }
  UINT primitive_count(void) const { return index_count_ / 3; }

  static HRESULT OnCreateDevice(ID3D10Device *device);
  static HRESULT OnLoadEffect(ID3D10Device *device, ID3D10Effect *effect);
  static void OnDestroyDevice(void);
  static void OnFrameMove(float elapsed_time, const D3DXVECTOR3 &camera_pos);

  static Block *GetBlockByID(const BLOCK_ID &id);

  static UINT queue_size(void) { return activation_queue_.size(); }
  static UINT vertex_buffers_total_size(void) { return vertex_buffers_total_size_; }
  static UINT index_buffers_total_size(void) { return index_buffers_total_size_; }
  static void ResetStats(void) { draw_calls_ = primitives_drawn_ = 0; }
  static UINT draw_calls(void) { return draw_calls_; }
  static UINT primitives_drawn(void) { return primitives_drawn_; }

  // Constants
  static const UINT kVoxelDim;
  static const UINT kVoxelDimMinusOne;
  static const float kInvVoxelDim;
  static const float kInvVoxelDimMinusOne;
  static const UINT kMargin;
  static const UINT kVoxelDimWithMargins;
  static const UINT kVoxelDimWithMarginsMinusOne;
  static const float kInvVoxelDimWithMargins;
  static const float kInvVoxelDimWithMarginsMinusOne;
  static const float kBlockSize;

 private:
  Block(const D3DXVECTOR3 &position);
  Block(const BLOCK_ID &id);
  ~Block(void);

  HRESULT ActivateReal(ID3D10Device *device);
  void DeactivateReal(void);
  void UpdateDistanceToCamera(void);

  // Generation steps
  HRESULT RenderDensityVolume(ID3D10Device *device);
  HRESULT GenerateTriangles(ID3D10Device *device);

  // Helper methods for stream-out-query
  static void InitQuery(ID3D10Device *device);
  static UINT64 GetQueryResult(void);

  D3DXVECTOR3 position_;
  BLOCK_ID id_;
  INT primitive_count_;
  INT index_count_;
  bool active_; // Are all buffers (vertex+index) created and filled with data?
  bool waiting_for_activation_;
  bool used_; // Is this block referenced by the octree?
  float activation_time_;
  float distance_to_camera_; // ... at the time when Activate() was called

  // Statistics...
  static DWORD vertex_buffers_total_size_;
  static DWORD index_buffers_total_size_;
  static UINT draw_calls_;
  static UINT primitives_drawn_;

  // Rendering resources
  ID3D10Buffer *vertex_buffer_;
  ID3D10Buffer *index_buffer_;
  static D3DXVECTOR3 camera_pos_;
  static ID3D10EffectScalarVariable *activation_time_ev_;
  static ID3D10InputLayout *input_layout_;

  // Generation resources
  static ID3D10Effect *effect_;
  static ID3D10Buffer *screen_aligned_quad_vb_;
  static ID3D10InputLayout *screen_aligned_quad_il_;
  static ID3D10Texture3D *density_volume_tex_;
  static ID3D10RenderTargetView *density_volume_rtv_;
  static ID3D10ShaderResourceView *density_volume_srv_;
  static ID3D10EffectShaderResourceVariable *density_volume_ev_;
  static ID3D10Texture3D *indices_volume_tex_;
  static ID3D10RenderTargetView *indices_volume_rtv_;
  static ID3D10ShaderResourceView *indices_volume_srv_;
  static ID3D10EffectShaderResourceVariable *indices_volume_ev_;
  static ID3D10Buffer *triangle_list_vb_;
  static ID3D10InputLayout *triangle_list_il_;
  static ID3D10Buffer *cells_vb_;
  static ID3D10InputLayout *cells_il_;
  static ID3D10Buffer *edges_vb_;
  static ID3D10InputLayout *edges_il_;
  static ID3D10Buffer *voxel_slice_vb_;
  static ID3D10InputLayout *voxel_slice_il_;
  static ID3D10EffectVectorVariable *offset_ev_;
  static ID3D10Query *query_;

  // Block cache
  typedef unordered_map_t<BLOCK_ID, Block *> BLOCK_CACHE;
  static BLOCK_CACHE cache_;

  // Activation queue
  struct CameraDistGreater : public std::binary_function<Block *, Block *, bool> {
    bool operator()(const Block *left, const Block *right) const {
      return left->distance_to_camera_ > right->distance_to_camera_;
    }
  };

  typedef std::priority_queue<Block *, std::vector<Block *>, CameraDistGreater > BLOCK_PQUEUE;
  typedef std::queue<Block *> BLOCK_QUEUE;
  static BLOCK_PQUEUE activation_queue_;
  static BLOCK_QUEUE deactivation_queue_;
};