src/landscape.h

   1 /* $Id: landscape.h 23735 2012-01-03 20:26:05Z rubidium $ */
   2
   3 /*
   4  * This file is part of OpenTTD.
   5  * OpenTTD 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, version 2.
   6  * OpenTTD 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.
   7  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   8  */
   9
  10 /** @file landscape.h Functions related to OTTD's landscape. */
  11
  12 #ifndef LANDSCAPE_H
  13 #define LANDSCAPE_H
  14
  15 #include "core/geometry_type.hpp"
  16 #include "tile_cmd.h"
  17
  18 static const uint SNOW_LINE_MONTHS = 12; ///< Number of months in the snow line table.
  19 static const uint SNOW_LINE_DAYS   = 32; ///< Number of days in each month in the snow line table.
  20
  21 /**
  22  * Structure describing the height of the snow line each day of the year
  23  * @ingroup SnowLineGroup
  24  */
  25 struct SnowLine {
  26         byte table[SNOW_LINE_MONTHS][SNOW_LINE_DAYS]; ///< Height of the snow line each day of the year
  27         byte highest_value; ///< Highest snow line of the year
  28         byte lowest_value;  ///< Lowest snow line of the year
  29 };
  30
  31 bool IsSnowLineSet();
  32 void SetSnowLine(byte table[SNOW_LINE_MONTHS][SNOW_LINE_DAYS]);
  33 uint16 GetSnowLine();
  34 uint16 HighestSnowLine();
  35 uint16 LowestSnowLine();
  36 void ClearSnowLine();
  37
  38 int GetSlopeZInCorner(Slope tileh, Corner corner);
  39 Slope GetFoundationSlope(TileIndex tile, int *z = nullptr);
  40
  41 uint GetPartialPixelZ(int x, int y, Slope corners);
  42 int GetSlopePixelZ(int x, int y);
  43 void GetSlopePixelZOnEdge(Slope tileh, DiagDirection edge, int *z1, int *z2);
  44
  45 /**
  46  * Determine the Z height of a corner relative to TileZ.
  47  *
  48  * @pre The slope must not be a halftile slope.
  49  *
  50  * @param tileh The slope.
  51  * @param corner The corner.
  52  * @return Z position of corner relative to TileZ.
  53  */
  54 static inline int GetSlopePixelZInCorner(Slope tileh, Corner corner)
  55 {
  56         return GetSlopeZInCorner(tileh, corner) * TILE_HEIGHT;
  57 }
  58
  59 /**
  60  * Get slope of a tile on top of a (possible) foundation
  61  * If a tile does not have a foundation, the function returns the same as GetTilePixelSlope.
  62  *
  63  * @param tile The tile of interest.
  64  * @param z returns the z of the foundation slope. (Can be nullptr, if not needed)
  65  * @return The slope on top of the foundation.
  66  */
  67 static inline Slope GetFoundationPixelSlope(TileIndex tile, int *z)
  68 {
  69         assert(z != nullptr);
  70         Slope s = GetFoundationSlope(tile, z);
  71         *z *= TILE_HEIGHT;
  72         return s;
  73 }
  74
  75 /**
  76  * Map 3D world or tile coordinate to equivalent 2D coordinate as used in the viewports and smallmap.
  77  * @param x X world or tile coordinate (runs in SW direction in the 2D view).
  78  * @param y Y world or tile coordinate (runs in SE direction in the 2D view).
  79  * @param z Z world or tile coordinate (runs in N direction in the 2D view).
  80  * @return Equivalent coordinate in the 2D view.
  81  * @see RemapCoords2
  82  */
  83 static inline Point RemapCoords(int x, int y, int z)
  84 {
  85         Point pt;
  86         pt.x = (y - x) * 2 * ZOOM_LVL_BASE;
  87         pt.y = (y + x - z) * ZOOM_LVL_BASE;
  88         return pt;
  89 }
  90
  91 /**
  92  * Map 3D world or tile coordinate to equivalent 2D coordinate as used in the viewports and smallmap.
  93  * Same as #RemapCoords, except the Z coordinate is read from the map.
  94  * @param x X world or tile coordinate (runs in SW direction in the 2D view).
  95  * @param y Y world or tile coordinate (runs in SE direction in the 2D view).
  96  * @return Equivalent coordinate in the 2D view.
  97  * @see RemapCoords
  98  */
  99 static inline Point RemapCoords2(int x, int y)
 100 {
 101         return RemapCoords(x, y, GetSlopePixelZ(x, y));
 102 }
 103
 104 /**
 105  * Map 2D viewport or smallmap coordinate to 3D world or tile coordinate.
 106  * Function assumes <tt>z == 0</tt>. For other values of \p z, add \p z to \a y before the call.
 107  * @param x X coordinate of the 2D coordinate.
 108  * @param y Y coordinate of the 2D coordinate.
 109  * @return X and Y components of equivalent world or tile coordinate.
 110  * @note Inverse of #RemapCoords function. Smaller values may get rounded.
 111  */
 112 static inline Point InverseRemapCoords(int x, int y)
 113 {
 114         Point pt = {(y * 2 - x) >> (2 + ZOOM_LVL_SHIFT), (y * 2 + x) >> (2 + ZOOM_LVL_SHIFT)};
 115         return pt;
 116 }
 117
 118 uint ApplyFoundationToSlope(Foundation f, Slope *s);
 119 /**
 120  * Applies a foundation to a slope.
 121  *
 122  * @pre      Foundation and slope must be valid combined.
 123  * @param f  The #Foundation.
 124  * @param s  The #Slope to modify.
 125  * @return   Increment to the tile Z coordinate.
 126  */
 127 static inline uint ApplyPixelFoundationToSlope(Foundation f, Slope *s)
 128 {
 129         return ApplyFoundationToSlope(f, s) * TILE_HEIGHT;
 130 }
 131
 132 void DrawFoundation(TileInfo *ti, Foundation f);
 133 bool HasFoundationNW(TileIndex tile, Slope slope_here, uint z_here);
 134 bool HasFoundationNE(TileIndex tile, Slope slope_here, uint z_here);
 135
 136 void DoClearSquare(TileIndex tile);
 137 void RunTileLoop();
 138
 139 void InitializeLandscape();
 140 void GenerateLandscape(byte mode);
 141
 142 #endif /* LANDSCAPE_H */