src/world/Block.hpp

   1 #ifndef BLANK_WORLD_BLOCK_HPP_
   2 #define BLANK_WORLD_BLOCK_HPP_
   3
   4 #include <iosfwd>
   5 #include <glm/glm.hpp>
   6
   7
   8 namespace blank {
   9
  10 /// single 1x1x1 cube
  11 struct Block {
  12
  13         using Type = unsigned short;
  14
  15         enum Face {
  16                 FACE_UP,
  17                 FACE_DOWN,
  18                 FACE_RIGHT,
  19                 FACE_LEFT,
  20                 FACE_FRONT,
  21                 FACE_BACK,
  22                 FACE_COUNT,
  23         };
  24         enum Turn {
  25                 TURN_NONE,
  26                 TURN_LEFT,
  27                 TURN_AROUND,
  28                 TURN_RIGHT,
  29                 TURN_COUNT,
  30         };
  31
  32         static constexpr int ORIENT_COUNT = FACE_COUNT * TURN_COUNT;
  33
  34         Type type;
  35         unsigned char orient;
  36
  37         constexpr explicit Block(Type type = 0, Face face = FACE_UP, Turn turn = TURN_NONE) noexcept
  38         : type(type), orient(face * TURN_COUNT + turn) { }
  39
  40         const glm::mat4 &Transform() const noexcept { return orient2transform[orient]; }
  41
  42         Face GetFace() const noexcept { return Face(orient / TURN_COUNT); }
  43         void SetFace(Face face) noexcept { orient = face * TURN_COUNT + GetTurn(); }
  44         Turn GetTurn() const noexcept { return Turn(orient % TURN_COUNT); }
  45         void SetTurn(Turn turn) noexcept { orient = GetFace() * TURN_COUNT + turn; }
  46
  47         Face OrientedFace(Face f) const noexcept { return orient2face[orient][f]; }
  48
  49         static Face Opposite(Face f) noexcept {
  50                 return Face(f ^ 1);
  51         }
  52
  53         static int Axis(Face f) noexcept {
  54                 switch (f) {
  55                         case FACE_UP:
  56                         case FACE_DOWN:
  57                                 return 1;
  58                         default:
  59                         case FACE_RIGHT:
  60                         case FACE_LEFT:
  61                                 return 0;
  62                         case FACE_FRONT:
  63                         case FACE_BACK:
  64                                 return 2;
  65                 }
  66         }
  67
  68         /// returns 1 for pro-axis, -1 for retro-axis, 0 for invalid faces
  69         static int Direction(Face f) noexcept {
  70                 switch (f) {
  71                         case FACE_RIGHT:
  72                         case FACE_UP:
  73                         case FACE_FRONT:
  74                                 return 1;
  75                         case FACE_LEFT:
  76                         case FACE_DOWN:
  77                         case FACE_BACK:
  78                                 return -1;
  79                         default:
  80                                 return 0;
  81                 }
  82         }
  83
  84         static glm::ivec3 FaceNormal(Face face) noexcept {
  85                 return face2normal[face];
  86         }
  87
  88         static Face NormalFace(const glm::vec3 &norm) noexcept {
  89                 const glm::vec3 anorm(abs(norm));
  90                 if (anorm.x > anorm.y) {
  91                         if (anorm.x > anorm.z) {
  92                                 return norm.x > 0.0f ? FACE_RIGHT : FACE_LEFT;
  93                         } else {
  94                                 return norm.z > 0.0f ? FACE_FRONT : FACE_BACK;
  95                         }
  96                 } else {
  97                         if (anorm.y > anorm.z) {
  98                                 return norm.y > 0.0f ? FACE_UP : FACE_DOWN;
  99                         } else {
 100                                 return norm.z > 0.0f ? FACE_FRONT : FACE_BACK;
 101                         }
 102                 }
 103         }
 104
 105         struct FaceSet {
 106
 107                 explicit FaceSet(unsigned char v = 0)
 108                 : value(v) { }
 109
 110                 bool IsSet(Face f) const {
 111                         return value & Mask(f);
 112                 }
 113                 void Set(Face f) {
 114                         value |= Mask(f);
 115                 }
 116                 void Unset(Face f) {
 117                         value &= ~Mask(f);
 118                 }
 119
 120                 void Clear() {
 121                         value = 0;
 122                 }
 123                 void Fill() {
 124                         value = Mask(FACE_COUNT) - 1;
 125                 }
 126
 127                 bool Empty() const {
 128                         return value == 0;
 129                 }
 130                 bool All() const {
 131                         return value == Mask(FACE_COUNT) - 1;
 132                 }
 133
 134                 unsigned char Mask(Face f) const {
 135                         return 1 << f;
 136                 }
 137
 138                 unsigned char value;
 139
 140         };
 141
 142 private:
 143         static const glm::ivec3 face2normal[6];
 144         static const glm::mat4 orient2transform[ORIENT_COUNT];
 145         static const Face orient2face[ORIENT_COUNT][FACE_COUNT];
 146
 147 };
 148
 149 inline bool operator ==(const Block &a, const Block &b) {
 150         return a.type == b.type && a.orient == b.orient;
 151 }
 152
 153 inline bool operator !=(const Block &a, const Block &b) {
 154         return !(a == b);
 155 }
 156
 157 std::ostream &operator <<(std::ostream &, const Block &);
 158 std::ostream &operator <<(std::ostream &, const Block::Face &);
 159 std::ostream &operator <<(std::ostream &, const Block::Turn &);
 160
 161 }
 162
 163 #endif