src/newgrf_canal.cpp

   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 newgrf_canal.cpp Implementation of NewGRF canals. */
   9
  10 #include "stdafx.h"
  11 #include "debug.h"
  12 #include "newgrf_spritegroup.h"
  13 #include "newgrf_canal.h"
  14 #include "water.h"
  15 #include "water_map.h"
  16 #include "spritecache.h"
  17
  18 #include "safeguards.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                 : ScopeResolver(ro), tile(tile)
  29         {
  30         }
  31
  32         uint32 GetRandomBits() const override;
  33         uint32 GetVariable(byte variable, uint32 parameter, bool *available) const override;
  34 };
  35
  36 /** Resolver object for canals. */
  37 struct CanalResolverObject : public ResolverObject {
  38         CanalScopeResolver canal_scope;
  39         CanalFeature feature;
  40
  41         CanalResolverObject(CanalFeature feature, TileIndex tile,
  42                         CallbackID callback = CBID_NO_CALLBACK, uint32 callback_param1 = 0, uint32 callback_param2 = 0);
  43
  44         ScopeResolver *GetScope(VarSpriteGroupScope scope = VSG_SCOPE_SELF, byte relative = 0) override
  45         {
  46                 switch (scope) {
  47                         case VSG_SCOPE_SELF: return &this->canal_scope;
  48                         default: return ResolverObject::GetScope(scope, relative);
  49                 }
  50         }
  51
  52         GrfSpecFeature GetFeature() const override;
  53         uint32 GetDebugID() const override;
  54 };
  55
  56 /* virtual */ uint32 CanalScopeResolver::GetRandomBits() const
  57 {
  58         /* Return random bits only for water tiles, not station tiles */
  59         return IsTileType(this->tile, MP_WATER) ? GetWaterTileRandomBits(this->tile) : 0;
  60 }
  61
  62 /* virtual */ uint32 CanalScopeResolver::GetVariable(byte variable, uint32 parameter, bool *available) const
  63 {
  64         switch (variable) {
  65                 /* Height of tile */
  66                 case 0x80: {
  67                         int z = GetTileZ(this->tile);
  68                         /* Return consistent height within locks */
  69                         if (IsTileType(this->tile, MP_WATER) && IsLock(this->tile) && GetLockPart(this->tile) == LOCK_PART_UPPER) z--;
  70                         return z;
  71                 }
  72
  73                 /* Terrain type */
  74                 case 0x81: return GetTerrainType(this->tile);
  75
  76                 /* Dike map: Connectivity info for river and canal tiles
  77                  *
  78                  * Assignment of bits to directions defined in agreement with
  79                  * http://projects.tt-forums.net/projects/ttdpatch/repository/revisions/2367/entry/trunk/patches/water.asm#L879
  80                  *         7
  81                  *      3     0
  82                  *   6     *     4
  83                  *      2     1
  84                  *         5
  85                  */
  86                 case 0x82: {
  87                         uint32 connectivity =
  88                                   (!IsWateredTile(TILE_ADDXY(tile, -1,  0), DIR_SW) << 0)  // NE
  89                                 + (!IsWateredTile(TILE_ADDXY(tile,  0,  1), DIR_NW) << 1)  // SE
  90                                 + (!IsWateredTile(TILE_ADDXY(tile,  1,  0), DIR_NE) << 2)  // SW
  91                                 + (!IsWateredTile(TILE_ADDXY(tile,  0, -1), DIR_SE) << 3)  // NW
  92                                 + (!IsWateredTile(TILE_ADDXY(tile, -1,  1), DIR_W)  << 4)  // E
  93                                 + (!IsWateredTile(TILE_ADDXY(tile,  1,  1), DIR_N)  << 5)  // S
  94                                 + (!IsWateredTile(TILE_ADDXY(tile,  1, -1), DIR_E)  << 6)  // W
  95                                 + (!IsWateredTile(TILE_ADDXY(tile, -1, -1), DIR_S)  << 7); // N
  96                         return connectivity;
  97                 }
  98
  99                 /* Random data for river or canal tiles, otherwise zero */
 100                 case 0x83: return IsTileType(this->tile, MP_WATER) ? GetWaterTileRandomBits(this->tile) : 0;
 101         }
 102
 103         Debug(grf, 1, "Unhandled canal variable 0x{:02X}", variable);
 104
 105         *available = false;
 106         return UINT_MAX;
 107 }
 108
 109 GrfSpecFeature CanalResolverObject::GetFeature() const
 110 {
 111         return GSF_CANALS;
 112 }
 113
 114 uint32 CanalResolverObject::GetDebugID() const
 115 {
 116         return this->feature;
 117 }
 118
 119 /**
 120  * Canal resolver constructor.
 121  * @param feature Which canal feature we want.
 122  * @param tile Tile index of canal.
 123  * @param callback Callback ID.
 124  * @param callback_param1 First parameter (var 10) of the callback.
 125  * @param callback_param2 Second parameter (var 18) of the callback.
 126  */
 127 CanalResolverObject::CanalResolverObject(CanalFeature feature, TileIndex tile,
 128                 CallbackID callback, uint32 callback_param1, uint32 callback_param2)
 129                 : ResolverObject(_water_feature[feature].grffile, callback, callback_param1, callback_param2), canal_scope(*this, tile), feature(feature)
 130 {
 131         this->root_spritegroup = _water_feature[feature].group;
 132 }
 133
 134 /**
 135  * Lookup the base sprite to use for a canal.
 136  * @param feature Which canal feature we want.
 137  * @param tile Tile index of canal, if appropriate.
 138  * @return Base sprite returned by GRF, or \c 0 if none.
 139  */
 140 SpriteID GetCanalSprite(CanalFeature feature, TileIndex tile)
 141 {
 142         CanalResolverObject object(feature, tile);
 143         const SpriteGroup *group = object.Resolve();
 144         if (group == nullptr) return 0;
 145
 146         return group->GetResult();
 147 }
 148
 149 /**
 150  * Run a specific callback for canals.
 151  * @param callback Callback ID.
 152  * @param param1   Callback parameter 1.
 153  * @param param2   Callback parameter 2.
 154  * @param feature  For which feature to run the callback.
 155  * @param tile     Tile index of canal.
 156  * @return Callback result or #CALLBACK_FAILED if the callback failed.
 157  */
 158 static uint16 GetCanalCallback(CallbackID callback, uint32 param1, uint32 param2, CanalFeature feature, TileIndex tile)
 159 {
 160         CanalResolverObject object(feature, tile, callback, param1, param2);
 161         return object.ResolveCallback();
 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 }