Pyrogenesis  trunk
Terrain.h
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1 /* Copyright (C) 2022 Wildfire Games.
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16  */
17 
18 /*
19  * Describes ground via heightmap and array of CPatch.
20  */
21 
22 #ifndef INCLUDED_TERRAIN
23 #define INCLUDED_TERRAIN
24 
25 #include "graphics/HeightMipmap.h"
26 #include "graphics/SColor.h"
27 #include "maths/Fixed.h"
28 #include "maths/Vector3D.h"
29 #include "ps/CStr.h"
30 
31 class CPatch;
32 class CMiniPatch;
33 class CFixedVector3D;
35 
36 ///////////////////////////////////////////////////////////////////////////////
37 // Terrain Constants:
38 
39 /// metres [world space units] per tile in x and z
41 
42 /// number of u16 height units per metre
44 
45 /// metres per u16 height unit
47 
48 ///////////////////////////////////////////////////////////////////////////////
49 // CTerrain: main terrain class; contains the heightmap describing elevation
50 // data, and the smaller subpatches that form the terrain
51 class CTerrain
52 {
53 public:
54  CTerrain();
55  ~CTerrain();
56 
57  // Coordinate naming convention: world-space coordinates are float x,z;
58  // tile-space coordinates are ssize_t i,j. rationale: signed types can
59  // more efficiently be converted to/from floating point. use ssize_t
60  // instead of int/long because these are sizes.
61 
62  bool Initialize(ssize_t patchesPerSide, const u16* ptr);
63 
64  // return number of vertices along edge of the terrain
65  ssize_t GetVerticesPerSide() const { return m_MapSize; }
66  // return number of tiles along edge of the terrain
67  ssize_t GetTilesPerSide() const { return GetVerticesPerSide()-1; }
68  // return number of patches along edge of the terrain
70 
71  float GetMinX() const { return 0.0f; }
72  float GetMinZ() const { return 0.0f; }
73  float GetMaxX() const { return (float)((m_MapSize-1) * TERRAIN_TILE_SIZE); }
74  float GetMaxZ() const { return (float)((m_MapSize-1) * TERRAIN_TILE_SIZE); }
75 
76  bool IsOnMap(float x, float z) const
77  {
78  return ((x >= GetMinX()) && (x < GetMaxX())
79  && (z >= GetMinZ()) && (z < GetMaxZ()));
80  }
81 
82  float GetVertexGroundLevel(ssize_t i, ssize_t j) const;
84  float GetExactGroundLevel(float x, float z) const;
86  float GetFilteredGroundLevel(float x, float z, float radius) const;
87 
88  // get the approximate slope of a tile
89  // (0 = horizontal, 0.5 = 30 degrees, 1.0 = 45 degrees, etc)
90  fixed GetSlopeFixed(ssize_t i, ssize_t j) const;
91 
92  // get the precise slope of a point, accounting for triangulation direction
93  fixed GetExactSlopeFixed(fixed x, fixed z) const;
94 
95  // Returns true if the triangulation diagonal for tile (i, j)
96  // should be in the direction (1,-1); false if it should be (1,1)
97  bool GetTriangulationDir(ssize_t i, ssize_t j) const;
98 
99  // Resize this terrain such that each side has given number of patches,
100  // with the center offset in patches from the center of the source.
101  void ResizeAndOffset(ssize_t size, ssize_t horizontalOffset = 0, ssize_t verticalOffset = 0);
102 
103  // set up a new heightmap from 16 bit data; assumes heightmap matches current terrain size
104  void SetHeightMap(u16* heightmap);
105  // return a pointer to the heightmap
106  u16* GetHeightMap() const { return m_Heightmap; }
107 
108  // get patch at given coordinates, expressed in patch-space; return 0 if
109  // coordinates represent patch off the edge of the map
110  CPatch* GetPatch(ssize_t i, ssize_t j) const;
111  // get tile at given coordinates, expressed in tile-space; return 0 if
112  // coordinates represent tile off the edge of the map
113  CMiniPatch* GetTile(ssize_t i, ssize_t j) const;
114 
115  // calculate the position of a given vertex
116  void CalcPosition(ssize_t i, ssize_t j, CVector3D& pos) const;
117  void CalcPositionFixed(ssize_t i, ssize_t j, CFixedVector3D& pos) const;
118  // calculate the vertex under a given position (rounding down coordinates)
119  static void CalcFromPosition(const CVector3D& pos, ssize_t& i, ssize_t& j)
120  {
121  i = (ssize_t)(pos.X/TERRAIN_TILE_SIZE);
122  j = (ssize_t)(pos.Z/TERRAIN_TILE_SIZE);
123  }
124  // calculate the vertex under a given position (rounding down coordinates)
125  static void CalcFromPosition(float x, float z, ssize_t& i, ssize_t& j)
126  {
127  i = (ssize_t)(x/TERRAIN_TILE_SIZE);
128  j = (ssize_t)(z/TERRAIN_TILE_SIZE);
129  }
130  // calculate the normal at a given vertex
131  void CalcNormal(ssize_t i, ssize_t j, CVector3D& normal) const;
132  void CalcNormalFixed(ssize_t i, ssize_t j, CFixedVector3D& normal) const;
133 
134  CVector3D CalcExactNormal(float x, float z) const;
135 
136  // Mark a specific square of tiles (inclusive lower bound, exclusive upper bound)
137  // as dirty - use this after modifying the heightmap.
138  // If you modify a vertex (i,j), you should dirty tiles
139  // from (i-1, j-1) [inclusive] to (i+1, j+1) [exclusive]
140  // since their geometry depends on that vertex.
141  // If you modify a tile (i,j), you should dirty tiles
142  // from (i-1, j-1) [inclusive] to (i+2, j+2) [exclusive]
143  // since their texture blends depend on that tile.
144  void MakeDirty(ssize_t i0, ssize_t j0, ssize_t i1, ssize_t j1, int dirtyFlags);
145  // mark the entire map as dirty
146  void MakeDirty(int dirtyFlags);
147 
148  /**
149  * Returns a 3D bounding box encompassing the given vertex range (inclusive)
150  */
152 
153  // get the base color for the terrain (typically pure white - other colors
154  // will interact badly with LOS - but used by the Actor Viewer tool)
155  SColor4ub GetBaseColor() const { return m_BaseColor; }
156  // set the base color for the terrain
157  void SetBaseColor(SColor4ub color) { m_BaseColor = color; }
158 
159  const CHeightMipmap& GetHeightMipmap() const { return m_HeightMipmap; }
160 
161 private:
162  // delete any data allocated by this terrain
163  void ReleaseData();
164  // setup patch pointers etc
165  void InitialisePatches();
166 
167  // size of this map in each direction, in vertices; ie. total tiles = sqr(m_MapSize-1)
169  // size of this map in each direction, in patches; total patches = sqr(m_MapSizePatches)
171  // the patches comprising this terrain
173  // 16-bit heightmap data
175  // base color (usually white)
177  // heightmap mipmap
179 };
180 
181 #endif // INCLUDED_TERRAIN
void ReleaseData()
Definition: Terrain.cpp:53
A simple fixed-point number class.
Definition: Fixed.h:119
float GetFilteredGroundLevel(float x, float z, float radius) const
Definition: Terrain.cpp:378
void MakeDirty(ssize_t i0, ssize_t j0, ssize_t i1, ssize_t j1, int dirtyFlags)
Definition: Terrain.cpp:757
CTerrain()
Definition: Terrain.cpp:37
const ssize_t TERRAIN_TILE_SIZE
metres [world space units] per tile in x and z
Definition: Terrain.h:40
SColor4ub m_BaseColor
Definition: Terrain.h:176
uint16_t u16
Definition: types.h:38
void ResizeAndOffset(ssize_t size, ssize_t horizontalOffset=0, ssize_t verticalOffset=0)
Definition: Terrain.cpp:482
CBoundingBoxAligned GetVertexesBound(ssize_t i0, ssize_t j0, ssize_t i1, ssize_t j1)
Returns a 3D bounding box encompassing the given vertex range (inclusive)
Definition: Terrain.cpp:804
void CalcPositionFixed(ssize_t i, ssize_t j, CFixedVector3D &pos) const
Definition: Terrain.cpp:114
void SetHeightMap(u16 *heightmap)
Definition: Terrain.cpp:734
float GetMaxZ() const
Definition: Terrain.h:74
void CalcPosition(ssize_t i, ssize_t j, CVector3D &pos) const
Definition: Terrain.cpp:102
Definition: Vector3D.h:30
Definition: Terrain.h:51
void CalcNormal(ssize_t i, ssize_t j, CVector3D &normal) const
Definition: Terrain.cpp:128
CPatch * m_Patches
Definition: Terrain.h:172
float GetExactGroundLevel(float x, float z) const
Definition: Terrain.cpp:389
float GetMinZ() const
Definition: Terrain.h:72
CMiniPatch * GetTile(ssize_t i, ssize_t j) const
Definition: Terrain.cpp:282
u16 * GetHeightMap() const
Definition: Terrain.h:106
SColor4ub GetBaseColor() const
Definition: Terrain.h:155
void SetBaseColor(SColor4ub color)
Definition: Terrain.h:157
Definition: HeightMipmap.h:41
float GetMaxX() const
Definition: Terrain.h:73
ssize_t GetVerticesPerSide() const
Definition: Terrain.h:65
float GetMinX() const
Definition: Terrain.h:71
float X
Definition: Vector3D.h:33
const float HEIGHT_SCALE
metres per u16 height unit
Definition: Terrain.h:46
static void CalcFromPosition(float x, float z, ssize_t &i, ssize_t &j)
Definition: Terrain.h:125
CVector3D CalcExactNormal(float x, float z) const
Definition: Terrain.cpp:219
CHeightMipmap m_HeightMipmap
Definition: Terrain.h:178
Definition: FixedVector3D.h:24
void InitialisePatches()
Definition: Terrain.cpp:719
Definition: SColor.h:30
CPatch * GetPatch(ssize_t i, ssize_t j) const
Definition: Terrain.cpp:267
Definition: Patch.h:48
void CalcNormalFixed(ssize_t i, ssize_t j, CFixedVector3D &normal) const
Definition: Terrain.cpp:175
bool Initialize(ssize_t patchesPerSide, const u16 *ptr)
Definition: Terrain.cpp:65
fixed GetVertexGroundLevelFixed(ssize_t i, ssize_t j) const
Definition: Terrain.cpp:299
intptr_t ssize_t
Definition: wposix_types.h:82
Definition: MiniPatch.h:28
Definition: BoundingBoxAligned.h:33
u16 * m_Heightmap
Definition: Terrain.h:174
fixed GetExactGroundLevelFixed(fixed x, fixed z) const
Definition: Terrain.cpp:434
fixed GetSlopeFixed(ssize_t i, ssize_t j) const
Definition: Terrain.cpp:307
bool IsOnMap(float x, float z) const
Definition: Terrain.h:76
float Z
Definition: Vector3D.h:33
ssize_t GetPatchesPerSide() const
Definition: Terrain.h:69
const CHeightMipmap & GetHeightMipmap() const
Definition: Terrain.h:159
float GetVertexGroundLevel(ssize_t i, ssize_t j) const
Definition: Terrain.cpp:292
static void CalcFromPosition(const CVector3D &pos, ssize_t &i, ssize_t &j)
Definition: Terrain.h:119
~CTerrain()
Definition: Terrain.cpp:45
ssize_t m_MapSizePatches
Definition: Terrain.h:170
bool GetTriangulationDir(ssize_t i, ssize_t j) const
Definition: Terrain.cpp:463
ssize_t GetTilesPerSide() const
Definition: Terrain.h:67
const ssize_t HEIGHT_UNITS_PER_METRE
number of u16 height units per metre
Definition: Terrain.h:43
ssize_t m_MapSize
Definition: Terrain.h:168
fixed GetExactSlopeFixed(fixed x, fixed z) const
Definition: Terrain.cpp:326