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