src/newgrf_canal.cpp

   1 /* $Id: newgrf_canal.cpp 26388 2014-03-03 20:02:31Z frosch $ */
   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                 : ScopeResolver(ro), tile(tile)
  30         {
  31         }
  32
  33         /* virtual */ uint32 GetRandomBits() const;
  34         /* virtual */ uint32 GetVariable(byte variable, uint32 parameter, bool *available) const;
  35 };
  36
  37 /** Resolver object for canals. */
  38 struct CanalResolverObject : public ResolverObject {
  39         CanalScopeResolver canal_scope;
  40
  41         CanalResolverObject(CanalFeature feature, TileIndex tile,
  42                         CallbackID callback = CBID_NO_CALLBACK, uint32 callback_param1 = 0, uint32 callback_param2 = 0);
  43
  44         /* virtual */ ScopeResolver *GetScope(VarSpriteGroupScope scope = VSG_SCOPE_SELF, byte relative = 0)
  45         {
  46                 switch (scope) {
  47                         case VSG_SCOPE_SELF: return &this->canal_scope;
  48                         default: return ResolverObject::GetScope(scope, relative);
  49                 }
  50         }
  51
  52         /* virtual */ const SpriteGroup *ResolveReal(const RealSpriteGroup *group) const;
  53 };
  54
  55 /* virtual */ uint32 CanalScopeResolver::GetRandomBits() const
  56 {
  57         /* Return random bits only for water tiles, not station tiles */
  58         return IsTileType(this->tile, MP_WATER) ? GetWaterTileRandomBits(this->tile) : 0;
  59 }
  60
  61 /* virtual */ uint32 CanalScopeResolver::GetVariable(byte variable, uint32 parameter, bool *available) const
  62 {
  63         switch (variable) {
  64                 /* Height of tile */
  65                 case 0x80: {
  66                         int z = GetTileZ(this->tile);
  67                         /* Return consistent height within locks */
  68                         if (IsTileType(this->tile, MP_WATER) && IsLock(this->tile) && GetLockPart(this->tile) == LOCK_PART_UPPER) z--;
  69                         return z;
  70                 }
  71
  72                 /* Terrain type */
  73                 case 0x81: return GetTerrainType(this->tile);
  74
  75                 /* Dike map: Connectivity info for river and canal tiles
  76                  *
  77                  * Assignment of bits to directions defined in agreement with
  78                  * http://projects.tt-forums.net/projects/ttdpatch/repository/revisions/2367/entry/trunk/patches/water.asm#L879
  79                  *         7
  80                  *      3     0
  81                  *   6     *     4
  82                  *      2     1
  83                  *         5
  84                  */
  85                 case 0x82: {
  86                         uint32 connectivity =
  87                                   (!IsWateredTile(TILE_ADDXY(tile, -1,  0), DIR_SW) << 0)  // NE
  88                                 + (!IsWateredTile(TILE_ADDXY(tile,  0,  1), DIR_NW) << 1)  // SE
  89                                 + (!IsWateredTile(TILE_ADDXY(tile,  1,  0), DIR_NE) << 2)  // SW
  90                                 + (!IsWateredTile(TILE_ADDXY(tile,  0, -1), DIR_SE) << 3)  // NW
  91                                 + (!IsWateredTile(TILE_ADDXY(tile, -1,  1), DIR_W)  << 4)  // E
  92                                 + (!IsWateredTile(TILE_ADDXY(tile,  1,  1), DIR_N)  << 5)  // S
  93                                 + (!IsWateredTile(TILE_ADDXY(tile,  1, -1), DIR_E)  << 6)  // W
  94                                 + (!IsWateredTile(TILE_ADDXY(tile, -1, -1), DIR_S)  << 7); // N
  95                         return connectivity;
  96                 }
  97
  98                 /* Random data for river or canal tiles, otherwise zero */
  99                 case 0x83: return IsTileType(this->tile, MP_WATER) ? GetWaterTileRandomBits(this->tile) : 0;
 100         }
 101
 102         DEBUG(grf, 1, "Unhandled canal variable 0x%02X", variable);
 103
 104         *available = false;
 105         return UINT_MAX;
 106 }
 107
 108
 109 /* virtual */ const SpriteGroup *CanalResolverObject::ResolveReal(const RealSpriteGroup *group) const
 110 {
 111         if (group->num_loaded == 0) return nullptr;
 112
 113         return group->loaded[0];
 114 }
 115
 116 /**
 117  * Canal resolver constructor.
 118  * @param feature Which canal feature we want.
 119  * @param tile Tile index of canal.
 120  * @param callback Callback ID.
 121  * @param callback_param1 First parameter (var 10) of the callback.
 122  * @param callback_param2 Second parameter (var 18) of the callback.
 123  */
 124 CanalResolverObject::CanalResolverObject(CanalFeature feature, TileIndex tile,
 125                 CallbackID callback, uint32 callback_param1, uint32 callback_param2)
 126                 : ResolverObject(_water_feature[feature].grffile, callback, callback_param1, callback_param2), canal_scope(*this, tile)
 127 {
 128         this->root_spritegroup = _water_feature[feature].group;
 129 }
 130
 131 /**
 132  * Lookup the base sprite to use for a canal.
 133  * @param feature Which canal feature we want.
 134  * @param tile Tile index of canal, if appropriate.
 135  * @return Base sprite returned by GRF, or \c 0 if none.
 136  */
 137 SpriteID GetCanalSprite(CanalFeature feature, TileIndex tile)
 138 {
 139         CanalResolverObject object(feature, tile);
 140         const SpriteGroup *group = object.Resolve();
 141         if (group == nullptr) return 0;
 142
 143         return group->GetResult();
 144 }
 145
 146 /**
 147  * Run a specific callback for canals.
 148  * @param callback Callback ID.
 149  * @param param1   Callback parameter 1.
 150  * @param param2   Callback parameter 2.
 151  * @param feature  For which feature to run the callback.
 152  * @param tile     Tile index of canal.
 153  * @return Callback result or #CALLBACK_FAILED if the callback failed.
 154  */
 155 static uint16 GetCanalCallback(CallbackID callback, uint32 param1, uint32 param2, CanalFeature feature, TileIndex tile)
 156 {
 157         CanalResolverObject object(feature, tile, callback, param1, param2);
 158         return object.ResolveCallback();
 159 }
 160
 161 /**
 162  * Get the new sprite offset for a water tile.
 163  * @param tile       Tile index of the canal/water tile.
 164  * @param feature    For which feature to get the new sprite offset.
 165  * @param cur_offset Current sprite offset.
 166  * @return New sprite offset.
 167  */
 168 uint GetCanalSpriteOffset(CanalFeature feature, TileIndex tile, uint cur_offset)
 169 {
 170         if (HasBit(_water_feature[feature].callback_mask, CBM_CANAL_SPRITE_OFFSET)) {
 171                 uint16 cb = GetCanalCallback(CBID_CANALS_SPRITE_OFFSET, cur_offset, 0, feature, tile);
 172                 if (cb != CALLBACK_FAILED) return cur_offset + cb;
 173         }
 174         return cur_offset;
 175 }