src/landscape.h

   1 /*
   2  * This file is part of OpenTTD.
   3  * 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.
   4  * 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.
   5  * 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/>.
   6  */
   7
   8 /** @file landscape.h Functions related to OTTD's landscape. */
   9
  10 #ifndef LANDSCAPE_H
  11 #define LANDSCAPE_H
  12
  13 #include "core/geometry_type.hpp"
  14 #include "tile_cmd.h"
  15
  16 static const uint SNOW_LINE_MONTHS = 12; ///< Number of months in the snow line table.
  17 static const uint SNOW_LINE_DAYS   = 32; ///< Number of days in each month in the snow line table.
  18
  19 /**
  20  * Structure describing the height of the snow line each day of the year
  21  * @ingroup SnowLineGroup
  22  */
  23 struct SnowLine {
  24         byte table[SNOW_LINE_MONTHS][SNOW_LINE_DAYS]; ///< Height of the snow line each day of the year
  25         byte highest_value; ///< Highest snow line of the year
  26         byte lowest_value;  ///< Lowest snow line of the year
  27 };
  28
  29 bool IsSnowLineSet();
  30 void SetSnowLine(byte table[SNOW_LINE_MONTHS][SNOW_LINE_DAYS]);
  31 byte GetSnowLine();
  32 byte HighestSnowLine();
  33 byte LowestSnowLine();
  34 void ClearSnowLine();
  35
  36 int GetSlopeZInCorner(Slope tileh, Corner corner);
  37 Slope GetFoundationSlope(TileIndex tile, int *z = nullptr);
  38
  39 uint GetPartialPixelZ(int x, int y, Slope corners);
  40 int GetSlopePixelZ(int x, int y);
  41 int GetSlopePixelZOutsideMap(int x, int y);
  42 void GetSlopePixelZOnEdge(Slope tileh, DiagDirection edge, int *z1, int *z2);
  43
  44 /**
  45  * Determine the Z height of a corner relative to TileZ.
  46  *
  47  * @pre The slope must not be a halftile slope.
  48  *
  49  * @param tileh The slope.
  50  * @param corner The corner.
  51  * @return Z position of corner relative to TileZ.
  52  */
  53 static inline int GetSlopePixelZInCorner(Slope tileh, Corner corner)
  54 {
  55         return GetSlopeZInCorner(tileh, corner) * TILE_HEIGHT;
  56 }
  57
  58 /**
  59  * Get slope of a tile on top of a (possible) foundation
  60  * If a tile does not have a foundation, the function returns the same as GetTilePixelSlope.
  61  *
  62  * @param tile The tile of interest.
  63  * @param z returns the z of the foundation slope. (Can be nullptr, if not needed)
  64  * @return The slope on top of the foundation.
  65  */
  66 static inline Slope GetFoundationPixelSlope(TileIndex tile, int *z)
  67 {
  68         assert(z != nullptr);
  69         Slope s = GetFoundationSlope(tile, z);
  70         *z *= TILE_HEIGHT;
  71         return s;
  72 }
  73
  74 /**
  75  * Map 3D world or tile coordinate to equivalent 2D coordinate as used in the viewports and smallmap.
  76  * @param x X world or tile coordinate (runs in SW direction in the 2D view).
  77  * @param y Y world or tile coordinate (runs in SE direction in the 2D view).
  78  * @param z Z world or tile coordinate (runs in N direction in the 2D view).
  79  * @return Equivalent coordinate in the 2D view.
  80  * @see RemapCoords2
  81  */
  82 static inline Point RemapCoords(int x, int y, int z)
  83 {
  84         Point pt;
  85         pt.x = (y - x) * 2 * ZOOM_LVL_BASE;
  86         pt.y = (y + x - z) * ZOOM_LVL_BASE;
  87         return pt;
  88 }
  89
  90 /**
  91  * Map 3D world or tile coordinate to equivalent 2D coordinate as used in the viewports and smallmap.
  92  * Same as #RemapCoords, except the Z coordinate is read from the map.
  93  * @param x X world or tile coordinate (runs in SW direction in the 2D view).
  94  * @param y Y world or tile coordinate (runs in SE direction in the 2D view).
  95  * @return Equivalent coordinate in the 2D view.
  96  * @see RemapCoords
  97  */
  98 static inline Point RemapCoords2(int x, int y)
  99 {
 100         return RemapCoords(x, y, GetSlopePixelZ(x, y));
 101 }
 102
 103 /**
 104  * Map 2D viewport or smallmap coordinate to 3D world or tile coordinate.
 105  * Function assumes <tt>z == 0</tt>. For other values of \p z, add \p z to \a y before the call.
 106  * @param x X coordinate of the 2D coordinate.
 107  * @param y Y coordinate of the 2D coordinate.
 108  * @return X and Y components of equivalent world or tile coordinate.
 109  * @note Inverse of #RemapCoords function. Smaller values may get rounded.
 110  * @see InverseRemapCoords2
 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 Point InverseRemapCoords2(int x, int y, bool clamp_to_map = false, bool *clamped = nullptr);
 119
 120 uint ApplyFoundationToSlope(Foundation f, Slope *s);
 121 /**
 122  * Applies a foundation to a slope.
 123  *
 124  * @pre      Foundation and slope must be valid combined.
 125  * @param f  The #Foundation.
 126  * @param s  The #Slope to modify.
 127  * @return   Increment to the tile Z coordinate.
 128  */
 129 static inline uint ApplyPixelFoundationToSlope(Foundation f, Slope *s)
 130 {
 131         return ApplyFoundationToSlope(f, s) * TILE_HEIGHT;
 132 }
 133
 134 void DrawFoundation(TileInfo *ti, Foundation f);
 135 bool HasFoundationNW(TileIndex tile, Slope slope_here, uint z_here);
 136 bool HasFoundationNE(TileIndex tile, Slope slope_here, uint z_here);
 137
 138 void DoClearSquare(TileIndex tile);
 139 void RunTileLoop();
 140
 141 void InitializeLandscape();
 142 void GenerateLandscape(byte mode);
 143
 144 #endif /* LANDSCAPE_H */