src/newgrf_canal.cpp

   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 newgrf_canal.cpp Implementation of NewGRF canals. */
  11
  12 #include "stdafx.h"
  13 #include "debug.h"
  14 #include "newgrf_spritegroup.h"
  15 #include "newgrf_canal.h"
  16 #include "water.h"
  17 #include "water_map.h"
  18
  19 #include "safeguards.h"
  20
  21 /** Table of canal 'feature' sprite groups */
  22 WaterFeature _water_feature[CF_END];
  23
  24 /** Scope resolver of a canal tile. */
  25 struct CanalScopeResolver : public ScopeResolver {
  26         TileIndex tile; ///< Tile containing the canal.
  27
  28         CanalScopeResolver(ResolverObject &ro, TileIndex tile);
  29
  30         /* virtual */ uint32 GetRandomBits() const;
  31         /* virtual */ uint32 GetVariable(byte variable, uint32 parameter, bool *available) const;
  32 };
  33
  34 /** Resolver object for canals. */
  35 struct CanalResolverObject : public ResolverObject {
  36         CanalScopeResolver canal_scope;
  37
  38         CanalResolverObject(CanalFeature feature, TileIndex tile,
  39                         CallbackID callback = CBID_NO_CALLBACK, uint32 callback_param1 = 0, uint32 callback_param2 = 0);
  40
  41         /* virtual */ ScopeResolver *GetScope(VarSpriteGroupScope scope = VSG_SCOPE_SELF, byte relative = 0)
  42         {
  43                 switch (scope) {
  44                         case VSG_SCOPE_SELF: return &this->canal_scope;
  45                         default: return ResolverObject::GetScope(scope, relative);
  46                 }
  47         }
  48
  49         /* virtual */ const SpriteGroup *ResolveReal(const RealSpriteGroup *group) const;
  50 };
  51
  52 /* virtual */ uint32 CanalScopeResolver::GetRandomBits() const
  53 {
  54         /* Return random bits only for water tiles, not station tiles */
  55         return IsTileType(this->tile, MP_WATER) ? GetWaterTileRandomBits(this->tile) : 0;
  56 }
  57
  58 /* virtual */ uint32 CanalScopeResolver::GetVariable(byte variable, uint32 parameter, bool *available) const
  59 {
  60         switch (variable) {
  61                 /* Height of tile */
  62                 case 0x80: {
  63                         int z = GetTileZ(this->tile);
  64                         /* Return consistent height within locks */
  65                         if (IsTileType(this->tile, MP_WATER) && IsLock(this->tile) && GetLockPart(this->tile) == LOCK_PART_UPPER) z--;
  66                         return z;
  67                 }
  68
  69                 /* Terrain type */
  70                 case 0x81: return GetTerrainType(this->tile);
  71
  72                 /* Dike map: Connectivity info for river and canal tiles
  73                  *
  74                  * Assignment of bits to directions defined in agreement with
  75                  * http://projects.tt-forums.net/projects/ttdpatch/repository/revisions/2367/entry/trunk/patches/water.asm#L879
  76                  *         7
  77                  *      3     0
  78                  *   6     *     4
  79                  *      2     1
  80                  *         5
  81                  */
  82                 case 0x82: {
  83                         uint32 connectivity =
  84                                   (!IsWateredTile(TILE_ADDXY(tile, -1,  0), DIR_SW) << 0)  // NE
  85                                 + (!IsWateredTile(TILE_ADDXY(tile,  0,  1), DIR_NW) << 1)  // SE
  86                                 + (!IsWateredTile(TILE_ADDXY(tile,  1,  0), DIR_NE) << 2)  // SW
  87                                 + (!IsWateredTile(TILE_ADDXY(tile,  0, -1), DIR_SE) << 3)  // NW
  88                                 + (!IsWateredTile(TILE_ADDXY(tile, -1,  1), DIR_W)  << 4)  // E
  89                                 + (!IsWateredTile(TILE_ADDXY(tile,  1,  1), DIR_N)  << 5)  // S
  90                                 + (!IsWateredTile(TILE_ADDXY(tile,  1, -1), DIR_E)  << 6)  // W
  91                                 + (!IsWateredTile(TILE_ADDXY(tile, -1, -1), DIR_S)  << 7); // N
  92                         return connectivity;
  93                 }
  94
  95                 /* Random data for river or canal tiles, otherwise zero */
  96                 case 0x83: return IsTileType(this->tile, MP_WATER) ? GetWaterTileRandomBits(this->tile) : 0;
  97         }
  98
  99         DEBUG(grf, 1, "Unhandled canal variable 0x%02X", variable);
 100
 101         *available = false;
 102         return UINT_MAX;
 103 }
 104
 105
 106 /* virtual */ const SpriteGroup *CanalResolverObject::ResolveReal(const RealSpriteGroup *group) const
 107 {
 108         if (group->num_loaded == 0) return NULL;
 109
 110         return group->loaded[0];
 111 }
 112
 113 CanalScopeResolver::CanalScopeResolver(ResolverObject &ro, TileIndex tile) : ScopeResolver(ro)
 114 {
 115         this->tile = tile;
 116 }
 117
 118 /**
 119  * Canal resolver constructor.
 120  * @param feature Which canal feature we want.
 121  * @param tile Tile index of canal.
 122  * @param callback Callback ID.
 123  * @param callback_param1 First parameter (var 10) of the callback.
 124  * @param callback_param2 Second parameter (var 18) of the callback.
 125  */
 126 CanalResolverObject::CanalResolverObject(CanalFeature feature, TileIndex tile,
 127                 CallbackID callback, uint32 callback_param1, uint32 callback_param2)
 128                 : ResolverObject(_water_feature[feature].grffile, callback, callback_param1, callback_param2), canal_scope(*this, tile)
 129 {
 130         this->root_spritegroup = _water_feature[feature].group;
 131 }
 132
 133 /**
 134  * Lookup the base sprite to use for a canal.
 135  * @param feature Which canal feature we want.
 136  * @param tile Tile index of canal, if appropriate.
 137  * @return Base sprite returned by GRF, or \c 0 if none.
 138  */
 139 SpriteID GetCanalSprite(CanalFeature feature, TileIndex tile)
 140 {
 141         CanalResolverObject object(feature, tile);
 142         const SpriteGroup *group = object.Resolve();
 143         if (group == NULL) return 0;
 144
 145         return group->GetResult();
 146 }
 147
 148 /**
 149  * Run a specific callback for canals.
 150  * @param callback Callback ID.
 151  * @param param1   Callback parameter 1.
 152  * @param param2   Callback parameter 2.
 153  * @param feature  For which feature to run the callback.
 154  * @param tile     Tile index of canal.
 155  * @return Callback result or #CALLBACK_FAILED if the callback failed.
 156  */
 157 static uint16 GetCanalCallback(CallbackID callback, uint32 param1, uint32 param2, CanalFeature feature, TileIndex tile)
 158 {
 159         CanalResolverObject object(feature, tile, callback, param1, param2);
 160         return object.ResolveCallback();
 161 }
 162
 163 /**
 164  * Get the new sprite offset for a water tile.
 165  * @param tile       Tile index of the canal/water tile.
 166  * @param feature    For which feature to get the new sprite offset.
 167  * @param cur_offset Current sprite offset.
 168  * @return New sprite offset.
 169  */
 170 uint GetCanalSpriteOffset(CanalFeature feature, TileIndex tile, uint cur_offset)
 171 {
 172         if (HasBit(_water_feature[feature].callback_mask, CBM_CANAL_SPRITE_OFFSET)) {
 173                 uint16 cb = GetCanalCallback(CBID_CANALS_SPRITE_OFFSET, cur_offset, 0, feature, tile);
 174                 if (cb != CALLBACK_FAILED) return cur_offset + cb;
 175         }
 176         return cur_offset;
 177 }