1
0
forked from 0ad/0ad
0ad/source/graphics/Terrain.h

170 lines
6.2 KiB
C
Raw Normal View History

/* Copyright (C) 2011 Wildfire Games.
* This file is part of 0 A.D.
*
* 0 A.D. is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* 0 A.D. is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with 0 A.D. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* Describes ground via heightmap and array of CPatch.
*/
#ifndef INCLUDED_TERRAIN
#define INCLUDED_TERRAIN
#include "maths/Vector3D.h"
#include "maths/Fixed.h"
#include "graphics/SColor.h"
class CPatch;
class CMiniPatch;
class CFixedVector3D;
class CStr8;
class CBoundingBoxAligned;
///////////////////////////////////////////////////////////////////////////////
// Terrain Constants:
/// metres [world space units] per tile in x and z
const ssize_t TERRAIN_TILE_SIZE = 4;
/// number of u16 height units per metre
const ssize_t HEIGHT_UNITS_PER_METRE = 732; // == approx int(256.0f/0.35f)
/// metres per u16 height unit
const float HEIGHT_SCALE = 1.f / HEIGHT_UNITS_PER_METRE;
///////////////////////////////////////////////////////////////////////////////
// CTerrain: main terrain class; contains the heightmap describing elevation
// data, and the smaller subpatches that form the terrain
class CTerrain
{
public:
CTerrain();
~CTerrain();
// Coordinate naming convention: world-space coordinates are float x,z;
// tile-space coordinates are ssize_t i,j. rationale: signed types can
// more efficiently be converted to/from floating point. use ssize_t
// instead of int/long because these are sizes.
bool Initialize(ssize_t patchesPerSide, const u16* ptr);
// return number of vertices along edge of the terrain
ssize_t GetVerticesPerSide() const { return m_MapSize; }
// return number of tiles along edge of the terrain
ssize_t GetTilesPerSide() const { return GetVerticesPerSide()-1; }
// return number of patches along edge of the terrain
ssize_t GetPatchesPerSide() const { return m_MapSizePatches; }
float GetMinX() const { return 0.0f; }
float GetMinZ() const { return 0.0f; }
float GetMaxX() const { return (float)((m_MapSize-1) * TERRAIN_TILE_SIZE); }
float GetMaxZ() const { return (float)((m_MapSize-1) * TERRAIN_TILE_SIZE); }
bool IsOnMap(float x, float z) const
{
return ((x >= GetMinX()) && (x < GetMaxX())
&& (z >= GetMinZ()) && (z < GetMaxZ()));
}
CStr8 GetMovementClass(ssize_t i, ssize_t j) const;
float GetVertexGroundLevel(ssize_t i, ssize_t j) const;
fixed GetVertexGroundLevelFixed(ssize_t i, ssize_t j) const;
float GetExactGroundLevel(float x, float z) const;
fixed GetExactGroundLevelFixed(fixed x, fixed z) const;
// get the approximate slope (0 = horizontal, 0.5 = 30 degrees, 1.0 = 45 degrees, etc)
fixed GetSlopeFixed(ssize_t i, ssize_t j) const;
// Returns true if the triangulation diagonal for tile (i, j)
// should be in the direction (1,-1); false if it should be (1,1)
bool GetTriangulationDir(ssize_t i, ssize_t j) const;
// resize this terrain such that each side has given number of patches
void Resize(ssize_t size);
// set up a new heightmap from 16 bit data; assumes heightmap matches current terrain size
void SetHeightMap(u16* heightmap);
// return a pointer to the heightmap
u16* GetHeightMap() const { return m_Heightmap; }
// get patch at given coordinates, expressed in patch-space; return 0 if
// coordinates represent patch off the edge of the map
CPatch* GetPatch(ssize_t i, ssize_t j) const;
// get tile at given coordinates, expressed in tile-space; return 0 if
// coordinates represent tile off the edge of the map
CMiniPatch* GetTile(ssize_t i, ssize_t j) const;
// calculate the position of a given vertex
void CalcPosition(ssize_t i, ssize_t j, CVector3D& pos) const;
void CalcPositionFixed(ssize_t i, ssize_t j, CFixedVector3D& pos) const;
// calculate the vertex under a given position (rounding down coordinates)
static void CalcFromPosition(const CVector3D& pos, ssize_t& i, ssize_t& j)
{
i = (ssize_t)(pos.X/TERRAIN_TILE_SIZE);
j = (ssize_t)(pos.Z/TERRAIN_TILE_SIZE);
}
// calculate the vertex under a given position (rounding down coordinates)
static void CalcFromPosition(float x, float z, ssize_t& i, ssize_t& j)
{
i = (ssize_t)(x/TERRAIN_TILE_SIZE);
j = (ssize_t)(z/TERRAIN_TILE_SIZE);
}
// calculate the normal at a given vertex
void CalcNormal(ssize_t i, ssize_t j, CVector3D& normal) const;
void CalcNormalFixed(ssize_t i, ssize_t j, CFixedVector3D& normal) const;
CVector3D CalcExactNormal(float x, float z) const;
// flatten out an area of terrain (specified in world space coords); return
// the average height of the flattened area
float FlattenArea(float x0, float x1, float z0, float z1);
// mark a specific square of tiles as dirty - use this after modifying the heightmap
void MakeDirty(ssize_t i0, ssize_t j0, ssize_t i1, ssize_t j1, int dirtyFlags);
// mark the entire map as dirty
void MakeDirty(int dirtyFlags);
/**
* Returns a 3D bounding box encompassing the given vertex range (inclusive)
*/
CBoundingBoxAligned GetVertexesBound(ssize_t i0, ssize_t j0, ssize_t i1, ssize_t j1);
// get the base colour for the terrain (typically pure white - other colours
// will interact badly with LOS - but used by the Actor Viewer tool)
SColor4ub GetBaseColour() const { return m_BaseColour; }
// set the base colour for the terrain
void SetBaseColour(SColor4ub colour) { m_BaseColour = colour; }
private:
// delete any data allocated by this terrain
void ReleaseData();
// setup patch pointers etc
void InitialisePatches();
// size of this map in each direction, in vertices; ie. total tiles = sqr(m_MapSize-1)
ssize_t m_MapSize;
// size of this map in each direction, in patches; total patches = sqr(m_MapSizePatches)
ssize_t m_MapSizePatches;
// the patches comprising this terrain
CPatch* m_Patches;
// 16-bit heightmap data
u16* m_Heightmap;
// base colour (usually white)
SColor4ub m_BaseColour;
};
#endif