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 "map/water.h"
  18 #include "map/slope.h"
  19
  20 /** Table of canal 'feature' sprite groups */
  21 WaterFeature _water_feature[CF_END];
  22
  23 /** Scope resolver of a canal tile. */
  24 struct CanalScopeResolver : public ScopeResolver {
  25         TileIndex tile; ///< Tile containing the canal.
  26
  27         CanalScopeResolver(ResolverObject &ro, TileIndex tile);
  28
  29         /* virtual */ uint32 GetRandomBits() const;
  30         /* virtual */ uint32 GetVariable(byte variable, uint32 parameter, bool *available) const;
  31 };
  32
  33 /** Resolver object for canals. */
  34 struct CanalResolverObject : public ResolverObject {
  35         CanalScopeResolver canal_scope;
  36
  37         CanalResolverObject(const GRFFile *grffile, TileIndex tile,
  38                         CallbackID callback = CBID_NO_CALLBACK, uint32 callback_param1 = 0, uint32 callback_param2 = 0);
  39
  40         /* virtual */ ScopeResolver *GetScope(VarSpriteGroupScope scope = VSG_SCOPE_SELF, byte relative = 0)
  41         {
  42                 switch (scope) {
  43                         case VSG_SCOPE_SELF: return &this->canal_scope;
  44                         default: return ResolverObject::GetScope(scope, relative);
  45                 }
  46         }
  47
  48         /* virtual */ const SpriteGroup *ResolveReal(const RealSpriteGroup *group) const;
  49 };
  50
  51 /* virtual */ uint32 CanalScopeResolver::GetRandomBits() const
  52 {
  53         /* Return random bits only for water tiles, not station tiles */
  54         return IsWaterTile(this->tile) ? GetWaterTileRandomBits(this->tile) : 0;
  55 }
  56
  57 /* virtual */ uint32 CanalScopeResolver::GetVariable(byte variable, uint32 parameter, bool *available) const
  58 {
  59         switch (variable) {
  60                 /* Height of tile */
  61                 case 0x80: {
  62                         int z = GetTileZ(this->tile);
  63                         /* Return consistent height within locks */
  64                         if (IsWaterTile(this->tile) && IsLock(this->tile) && GetLockPart(this->tile) == LOCK_PART_UPPER) z--;
  65                         return z;
  66                 }
  67
  68                 /* Terrain type */
  69                 case 0x81: return GetTerrainType(this->tile);
  70
  71                 /* Dike map: Connectivity info for river and canal tiles
  72                  *
  73                  * Assignment of bits to directions defined in agreement with
  74                  * http://projects.tt-forums.net/projects/ttdpatch/repository/revisions/2367/entry/trunk/patches/water.asm#L879
  75                  *         7
  76                  *      3     0
  77                  *   6     *     4
  78                  *      2     1
  79                  *         5
  80                  */
  81                 case 0x82: {
  82                         uint32 connectivity =
  83                                   (!IsWateredTile(TILE_ADDXY(tile, -1,  0), DIR_SW) << 0)  // NE
  84                                 + (!IsWateredTile(TILE_ADDXY(tile,  0,  1), DIR_NW) << 1)  // SE
  85                                 + (!IsWateredTile(TILE_ADDXY(tile,  1,  0), DIR_NE) << 2)  // SW
  86                                 + (!IsWateredTile(TILE_ADDXY(tile,  0, -1), DIR_SE) << 3)  // NW
  87                                 + (!IsWateredTile(TILE_ADDXY(tile, -1,  1), DIR_W)  << 4)  // E
  88                                 + (!IsWateredTile(TILE_ADDXY(tile,  1,  1), DIR_N)  << 5)  // S
  89                                 + (!IsWateredTile(TILE_ADDXY(tile,  1, -1), DIR_E)  << 6)  // W
  90                                 + (!IsWateredTile(TILE_ADDXY(tile, -1, -1), DIR_S)  << 7); // N
  91                         return connectivity;
  92                 }
  93
  94                 /* Random data for river or canal tiles, otherwise zero */
  95                 case 0x83: return IsWaterTile(this->tile) ? GetWaterTileRandomBits(this->tile) : 0;
  96         }
  97
  98         DEBUG(grf, 1, "Unhandled canal variable 0x%02X", variable);
  99
 100         *available = false;
 101         return UINT_MAX;
 102 }
 103
 104
 105 /* virtual */ const SpriteGroup *CanalResolverObject::ResolveReal(const RealSpriteGroup *group) const
 106 {
 107         if (group->num_loaded == 0) return NULL;
 108
 109         return group->loaded[0];
 110 }
 111
 112 CanalScopeResolver::CanalScopeResolver(ResolverObject &ro, TileIndex tile) : ScopeResolver(ro)
 113 {
 114         this->tile = tile;
 115 }
 116
 117 /**
 118  * Canal resolver constructor.
 119  * @param grffile Grf file.
 120  * @param tile Tile index of canal.
 121  * @param callback Callback ID.
 122  * @param callback_param1 First parameter (var 10) of the callback.
 123  * @param callback_param2 Second parameter (var 18) of the callback.
 124  */
 125 CanalResolverObject::CanalResolverObject(const GRFFile *grffile, TileIndex tile,
 126                 CallbackID callback, uint32 callback_param1, uint32 callback_param2)
 127                 : ResolverObject(grffile, callback, callback_param1, callback_param2), canal_scope(*this, tile)
 128 {
 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(_water_feature[feature].grffile, tile);
 140         const SpriteGroup *group = SpriteGroup::Resolve(_water_feature[feature].group, object);
 141         if (group == NULL) 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(_water_feature[feature].grffile, tile, callback, param1, param2);
 158         const SpriteGroup *group = SpriteGroup::Resolve(_water_feature[feature].group, object);
 159         if (group == NULL) return CALLBACK_FAILED;
 160
 161         return group->GetCallbackResult();
 162 }
 163
 164 /**
 165  * Get the new sprite offset for a water tile.
 166  * @param tile       Tile index of the canal/water tile.
 167  * @param feature    For which feature to get the new sprite offset.
 168  * @param cur_offset Current sprite offset.
 169  * @return New sprite offset.
 170  */
 171 uint GetCanalSpriteOffset(CanalFeature feature, TileIndex tile, uint cur_offset)
 172 {
 173         if (HasBit(_water_feature[feature].callback_mask, CBM_CANAL_SPRITE_OFFSET)) {
 174                 uint16 cb = GetCanalCallback(CBID_CANALS_SPRITE_OFFSET, cur_offset, 0, feature, tile);
 175                 if (cb != CALLBACK_FAILED) return cur_offset + cb;
 176         }
 177         return cur_offset;
 178 }