1 /* Copyright (C) 2011 Wildfire Games. 2 * This file is part of 0 A.D. 3 * 4 * 0 A.D. is free software: you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation, either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * 0 A.D. is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with 0 A.D. If not, see <http://www.gnu.org/licenses/>. 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 "maths/Vector3D.h" 26 #include "maths/Fixed.h" 27 #include "graphics/SColor.h" 28 #include "graphics/HeightMipmap.h" 29 30 class CPatch; 31 class CMiniPatch; 32 class CFixedVector3D; 33 class CStr8; 34 class CBoundingBoxAligned; 35 36 /////////////////////////////////////////////////////////////////////////////// 37 // Terrain Constants: 38 39 /// metres [world space units] per tile in x and z 40 const ssize_t TERRAIN_TILE_SIZE = 4; 41 42 /// number of u16 height units per metre 43 const ssize_t HEIGHT_UNITS_PER_METRE = 92; 44 45 /// metres per u16 height unit 46 const float HEIGHT_SCALE = 1.f / HEIGHT_UNITS_PER_METRE; 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 GetVerticesPerSide()65 ssize_t GetVerticesPerSide() const { return m_MapSize; } 66 // return number of tiles along edge of the terrain GetTilesPerSide()67 ssize_t GetTilesPerSide() const { return GetVerticesPerSide()-1; } 68 // return number of patches along edge of the terrain GetPatchesPerSide()69 ssize_t GetPatchesPerSide() const { return m_MapSizePatches; } 70 GetMinX()71 float GetMinX() const { return 0.0f; } GetMinZ()72 float GetMinZ() const { return 0.0f; } GetMaxX()73 float GetMaxX() const { return (float)((m_MapSize-1) * TERRAIN_TILE_SIZE); } GetMaxZ()74 float GetMaxZ() const { return (float)((m_MapSize-1) * TERRAIN_TILE_SIZE); } 75 IsOnMap(float x,float z)76 bool IsOnMap(float x, float z) const 77 { 78 return ((x >= GetMinX()) && (x < GetMaxX()) 79 && (z >= GetMinZ()) && (z < GetMaxZ())); 80 } 81 82 CStr8 GetMovementClass(ssize_t i, ssize_t j) const; 83 84 float GetVertexGroundLevel(ssize_t i, ssize_t j) const; 85 fixed GetVertexGroundLevelFixed(ssize_t i, ssize_t j) const; 86 float GetExactGroundLevel(float x, float z) const; 87 fixed GetExactGroundLevelFixed(fixed x, fixed z) const; 88 float GetFilteredGroundLevel(float x, float z, float radius) const; 89 90 // get the approximate slope of a tile 91 // (0 = horizontal, 0.5 = 30 degrees, 1.0 = 45 degrees, etc) 92 fixed GetSlopeFixed(ssize_t i, ssize_t j) const; 93 94 // get the precise slope of a point, accounting for triangulation direction 95 fixed GetExactSlopeFixed(fixed x, fixed z) const; 96 97 // Returns true if the triangulation diagonal for tile (i, j) 98 // should be in the direction (1,-1); false if it should be (1,1) 99 bool GetTriangulationDir(ssize_t i, ssize_t j) const; 100 101 // resize this terrain such that each side has given number of patches 102 void Resize(ssize_t size); 103 104 // set up a new heightmap from 16 bit data; assumes heightmap matches current terrain size 105 void SetHeightMap(u16* heightmap); 106 // return a pointer to the heightmap GetHeightMap()107 u16* GetHeightMap() const { return m_Heightmap; } 108 109 // get patch at given coordinates, expressed in patch-space; return 0 if 110 // coordinates represent patch off the edge of the map 111 CPatch* GetPatch(ssize_t i, ssize_t j) const; 112 // get tile at given coordinates, expressed in tile-space; return 0 if 113 // coordinates represent tile off the edge of the map 114 CMiniPatch* GetTile(ssize_t i, ssize_t j) const; 115 116 // calculate the position of a given vertex 117 void CalcPosition(ssize_t i, ssize_t j, CVector3D& pos) const; 118 void CalcPositionFixed(ssize_t i, ssize_t j, CFixedVector3D& pos) const; 119 // calculate the vertex under a given position (rounding down coordinates) CalcFromPosition(const CVector3D & pos,ssize_t & i,ssize_t & j)120 static void CalcFromPosition(const CVector3D& pos, ssize_t& i, ssize_t& j) 121 { 122 i = (ssize_t)(pos.X/TERRAIN_TILE_SIZE); 123 j = (ssize_t)(pos.Z/TERRAIN_TILE_SIZE); 124 } 125 // calculate the vertex under a given position (rounding down coordinates) CalcFromPosition(float x,float z,ssize_t & i,ssize_t & j)126 static void CalcFromPosition(float x, float z, ssize_t& i, ssize_t& j) 127 { 128 i = (ssize_t)(x/TERRAIN_TILE_SIZE); 129 j = (ssize_t)(z/TERRAIN_TILE_SIZE); 130 } 131 // calculate the normal at a given vertex 132 void CalcNormal(ssize_t i, ssize_t j, CVector3D& normal) const; 133 void CalcNormalFixed(ssize_t i, ssize_t j, CFixedVector3D& normal) const; 134 135 CVector3D CalcExactNormal(float x, float z) const; 136 137 // Mark a specific square of tiles (inclusive lower bound, exclusive upper bound) 138 // as dirty - use this after modifying the heightmap. 139 // If you modify a vertex (i,j), you should dirty tiles 140 // from (i-1, j-1) [inclusive] to (i+1, j+1) [exclusive] 141 // since their geometry depends on that vertex. 142 // If you modify a tile (i,j), you should dirty tiles 143 // from (i-1, j-1) [inclusive] to (i+2, j+2) [exclusive] 144 // since their texture blends depend on that tile. 145 void MakeDirty(ssize_t i0, ssize_t j0, ssize_t i1, ssize_t j1, int dirtyFlags); 146 // mark the entire map as dirty 147 void MakeDirty(int dirtyFlags); 148 149 /** 150 * Returns a 3D bounding box encompassing the given vertex range (inclusive) 151 */ 152 CBoundingBoxAligned GetVertexesBound(ssize_t i0, ssize_t j0, ssize_t i1, ssize_t j1); 153 154 // get the base color for the terrain (typically pure white - other colors 155 // will interact badly with LOS - but used by the Actor Viewer tool) GetBaseColor()156 SColor4ub GetBaseColor() const { return m_BaseColor; } 157 // set the base color for the terrain SetBaseColor(SColor4ub color)158 void SetBaseColor(SColor4ub color) { m_BaseColor = color; } 159 GetHeightMipmap()160 const CHeightMipmap& GetHeightMipmap() const { return m_HeightMipmap; } 161 162 private: 163 // delete any data allocated by this terrain 164 void ReleaseData(); 165 // setup patch pointers etc 166 void InitialisePatches(); 167 168 // size of this map in each direction, in vertices; ie. total tiles = sqr(m_MapSize-1) 169 ssize_t m_MapSize; 170 // size of this map in each direction, in patches; total patches = sqr(m_MapSizePatches) 171 ssize_t m_MapSizePatches; 172 // the patches comprising this terrain 173 CPatch* m_Patches; 174 // 16-bit heightmap data 175 u16* m_Heightmap; 176 // base color (usually white) 177 SColor4ub m_BaseColor; 178 // heightmap mipmap 179 CHeightMipmap m_HeightMipmap; 180 }; 181 182 #endif 183