src/bridge.h

   1 /* $Id$ */
   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 bridge.h Header file for bridges */
  11
  12 #ifndef BRIDGE_H
  13 #define BRIDGE_H
  14
  15 #include "gfx_type.h"
  16 #include "tile_cmd.h"
  17 #include "slope_func.h"
  18 #include "viewport_func.h"
  19
  20 /**
  21  * This enum is related to the definition of bridge pieces,
  22  * which is used to determine the proper sprite table to use
  23  * while drawing a given bridge part.
  24  */
  25 enum BridgePieces {
  26         BRIDGE_PIECE_NORTH = 0,
  27         BRIDGE_PIECE_SOUTH,
  28         BRIDGE_PIECE_INNER_NORTH,
  29         BRIDGE_PIECE_INNER_SOUTH,
  30         BRIDGE_PIECE_MIDDLE_ODD,
  31         BRIDGE_PIECE_MIDDLE_EVEN,
  32         BRIDGE_PIECE_HEAD,
  33         BRIDGE_PIECE_INVALID,
  34 };
  35
  36 DECLARE_POSTFIX_INCREMENT(BridgePieces)
  37
  38 static const uint MAX_BRIDGES = 13; ///< Maximal number of available bridge specs.
  39
  40 typedef uint BridgeType; ///< Bridge spec number.
  41
  42 /**
  43  * Struct containing information about a single bridge type
  44  */
  45 struct BridgeSpec {
  46         Year avail_year;             ///< the year where it becomes available
  47         byte min_length;             ///< the minimum length (not counting start and end tile)
  48         uint16 max_length;           ///< the maximum length (not counting start and end tile)
  49         uint16 price;                ///< the price multiplier
  50         uint16 speed;                ///< maximum travel speed (1 unit = 1/1.6 mph = 1 km-ish/h)
  51         SpriteID sprite;             ///< the sprite which is used in the GUI
  52         PaletteID pal;               ///< the palette which is used in the GUI
  53         StringID material;           ///< the string that contains the bridge description
  54         StringID transport_name[2];  ///< description of the bridge, when built for road or rail
  55         PalSpriteID **sprite_table;  ///< table of sprites for drawing the bridge
  56         byte flags;                  ///< bit 0 set: disable drawing of far pillars.
  57 };
  58
  59 extern BridgeSpec _bridge[MAX_BRIDGES];
  60
  61 Foundation GetBridgeFoundation(Slope tileh, Axis axis);
  62 bool HasBridgeFlatRamp(Slope tileh, Axis axis);
  63
  64 /**
  65  * Get the height increase for a bridge ramp
  66  * @param dir Bridge direction
  67  * @param x x within the tile
  68  * @param y y within the tile
  69  */
  70 static inline int GetBridgePartialPixelZ(DiagDirection dir, uint x, uint y)
  71 {
  72         assert(x < TILE_SIZE);
  73         assert(y < TILE_SIZE);
  74
  75         return DistanceFromTileEdge(ReverseDiagDir(dir), x, y) / 2 + 1;
  76 }
  77
  78 /**
  79  * Get the direction(s) to which rail/road can be connected in an extended bridgehead.
  80  * @param tileh Slope of the tile
  81  * @param dir Direction of the bridge
  82  * @return DIAGDIRDIFF_SAME for all directions allowed; DIAGDIRDIFF_REVERSE for none (invalid slope); else invalid direction as a difference from dir
  83  */
  84 static inline DiagDirDiff CheckExtendedBridgeHead(Slope tileh, DiagDirection dir)
  85 {
  86         extern const uint32 bridgehead_valid_slopes[DIAGDIR_END][2];
  87
  88         assert (tileh < 32);
  89
  90         if (tileh == InclinedSlope(ReverseDiagDir(dir))) {
  91                 return DIAGDIRDIFF_SAME;
  92         } else if (HasBit (bridgehead_valid_slopes[dir][0], tileh)) {
  93                 return DIAGDIRDIFF_90RIGHT;
  94         } else if (HasBit (bridgehead_valid_slopes[dir][1], tileh)) {
  95                 return DIAGDIRDIFF_90LEFT;
  96         } else {
  97                 return DIAGDIRDIFF_REVERSE;
  98         }
  99 }
 100
 101 /**
 102  * Get the specification of a bridge type.
 103  * @param i The type of bridge to get the specification for.
 104  * @return The specification.
 105  */
 106 static inline const BridgeSpec *GetBridgeSpec(BridgeType i)
 107 {
 108         assert(i < lengthof(_bridge));
 109         return &_bridge[i];
 110 }
 111
 112 int GetBridgeHeight(TileIndex tile);
 113 /**
 114  * Get the height ('z') of a bridge in pixels.
 115  * @param tile the bridge ramp tile to get the bridge height from
 116  * @return the height of the bridge in pixels
 117  */
 118 static inline int GetBridgePixelHeight(TileIndex tile)
 119 {
 120         return GetBridgeHeight(tile) * TILE_HEIGHT;
 121 }
 122
 123 void DrawBridgeTramBits(int x, int y, int z, int offset, bool overlay, bool head);
 124 void DrawBridgeMiddle(const TileInfo *ti);
 125 void DrawBridgeGround(TileInfo *ti);
 126 const PalSpriteID *GetBridgeRampSprite(int index, int offset, Slope slope, DiagDirection dir);
 127 void DrawAqueductRamp(TileInfo *ti);
 128
 129 CommandCost CheckBridgeAvailability(BridgeType bridge_type, uint bridge_len, DoCommandFlag flags = DC_NONE);
 130 int CalcBridgeLenCostFactor(int x);
 131
 132 void ResetBridges();
 133
 134 CommandCost CheckBridgeTiles(TileIndex tile1, TileIndex tile2, Axis *axis);
 135
 136 CommandCost CheckBridgeBuildable (TileIndex tile1, TileIndex tile2,
 137         DoCommandFlag flags, bool clear1, bool clear2, int *height,
 138         bool restricted = false);
 139
 140 CommandCost CheckBridgeSlope(DiagDirection dir, Slope *tileh, int *z);
 141
 142 void MarkBridgeTilesDirty (TileIndex start, TileIndex end, DiagDirection dir,
 143         bool first = true);
 144
 145 void SetBridgeMiddleTiles (TileIndex tile1, TileIndex tile2, Axis direction,
 146         int height);
 147
 148 void RemoveBridgeMiddleTiles(TileIndex tile1, TileIndex tile2);
 149
 150 #endif /* BRIDGE_H */