Line data Source code
1 : /* Copyright (C) 2022 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 "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;
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
65 43682 : ssize_t GetVerticesPerSide() const { return m_MapSize; }
66 : // return number of tiles along edge of the terrain
67 0 : ssize_t GetTilesPerSide() const { return GetVerticesPerSide()-1; }
68 : // return number of patches along edge of the terrain
69 2061 : ssize_t GetPatchesPerSide() const { return m_MapSizePatches; }
70 :
71 0 : float GetMinX() const { return 0.0f; }
72 0 : float GetMinZ() const { return 0.0f; }
73 0 : float GetMaxX() const { return (float)((m_MapSize-1) * TERRAIN_TILE_SIZE); }
74 0 : float GetMaxZ() const { return (float)((m_MapSize-1) * TERRAIN_TILE_SIZE); }
75 :
76 0 : bool IsOnMap(float x, float z) const
77 : {
78 0 : return ((x >= GetMinX()) && (x < GetMaxX())
79 0 : && (z >= GetMinZ()) && (z < GetMaxZ()));
80 : }
81 :
82 : float GetVertexGroundLevel(ssize_t i, ssize_t j) const;
83 : fixed GetVertexGroundLevelFixed(ssize_t i, ssize_t j) const;
84 : float GetExactGroundLevel(float x, float z) const;
85 : fixed GetExactGroundLevelFixed(fixed x, fixed 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 43669 : 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 0 : static void CalcFromPosition(const CVector3D& pos, ssize_t& i, ssize_t& j)
120 : {
121 0 : i = (ssize_t)(pos.X/TERRAIN_TILE_SIZE);
122 0 : j = (ssize_t)(pos.Z/TERRAIN_TILE_SIZE);
123 0 : }
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 : */
151 : CBoundingBoxAligned GetVertexesBound(ssize_t i0, ssize_t j0, ssize_t i1, ssize_t j1);
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 0 : 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)
168 : ssize_t m_MapSize;
169 : // size of this map in each direction, in patches; total patches = sqr(m_MapSizePatches)
170 : ssize_t m_MapSizePatches;
171 : // the patches comprising this terrain
172 : CPatch* m_Patches;
173 : // 16-bit heightmap data
174 : u16* m_Heightmap;
175 : // base color (usually white)
176 : SColor4ub m_BaseColor;
177 : // heightmap mipmap
178 : CHeightMipmap m_HeightMipmap;
179 : };
180 :
181 : #endif // INCLUDED_TERRAIN
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