elrail.cpp

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/* $Id: elrail.cpp 14422 2008-09-30 20:51:04Z rubidium $ */

#include "stdafx.h"
#include "openttd.h"
#include "station_map.h"
#include "viewport_func.h"
#include "settings_type.h"
#include "landscape.h"
#include "rail_type.h"
#include "debug.h"
#include "tunnel_map.h"
#include "road_map.h"
#include "bridge_map.h"
#include "bridge.h"
#include "rail_map.h"
#include "train.h"
#include "rail_gui.h"
#include "transparency.h"
#include "tunnelbridge_map.h"
#include "vehicle_func.h"
#include "company_base.h"
#include "tunnelbridge.h"
#include "engine_func.h"
#include "elrail_func.h"
#include "engine_base.h"

#include "table/sprites.h"
#include "table/elrail_data.h"

static inline TLG GetTLG(TileIndex t)
{
  return (TLG)((HasBit(TileX(t), 0) << 1) + HasBit(TileY(t), 0));
}

static TrackBits GetRailTrackBitsUniversal(TileIndex t, byte *override)
{
  switch (GetTileType(t)) {
    case MP_RAILWAY:
      if (!HasCatenary(GetRailType(t))) return TRACK_BIT_NONE;
      switch (GetRailTileType(t)) {
        case RAIL_TILE_NORMAL: case RAIL_TILE_SIGNALS:
          return GetTrackBits(t);
        case RAIL_TILE_WAYPOINT:
          return GetRailWaypointBits(t);
        default:
          return TRACK_BIT_NONE;
      }
      break;

    case MP_TUNNELBRIDGE:
      if (!HasCatenary(GetRailType(t))) return TRACK_BIT_NONE;
      if (override != NULL && (IsTunnel(t) || GetTunnelBridgeLength(t, GetOtherBridgeEnd(t)) > 0)) {
        *override = 1 << GetTunnelBridgeDirection(t);
      }
      return DiagDirToDiagTrackBits(GetTunnelBridgeDirection(t));

    case MP_ROAD:
      if (!IsLevelCrossing(t)) return TRACK_BIT_NONE;
      if (!HasCatenary(GetRailType(t))) return TRACK_BIT_NONE;
      return GetCrossingRailBits(t);

    case MP_STATION:
      if (!IsRailwayStation(t)) return TRACK_BIT_NONE;
      if (!HasCatenary(GetRailType(t))) return TRACK_BIT_NONE;
      if (!IsStationTileElectrifiable(t)) return TRACK_BIT_NONE;
      return TrackToTrackBits(GetRailStationTrack(t));

    default:
      return TRACK_BIT_NONE;
  }
}

static void AdjustTileh(TileIndex tile, Slope *tileh)
{
  if (IsTileType(tile, MP_TUNNELBRIDGE)) {
    if (IsTunnel(tile)) {
      *tileh = SLOPE_STEEP; // XXX - Hack to make tunnel entrances to always have a pylon
    } else if (*tileh != SLOPE_FLAT) {
      *tileh = SLOPE_FLAT;
    } else {
      *tileh = InclinedSlope(GetTunnelBridgeDirection(tile));
    }
  }
}

static byte GetPCPElevation(TileIndex tile, DiagDirection PCPpos)
{
  /* The elevation of the "pylon"-sprite should be the elevation at the PCP.
   * PCPs are always on a tile edge.
   *
   * This position can be outside of the tile, i.e. ?_pcp_offset == TILE_SIZE > TILE_SIZE - 1.
   * So we have to move it inside the tile, because if the neighboured tile has a foundation,
   * that does not smoothly connect to the current tile, we will get a wrong elevation from GetSlopeZ().
   *
   * When we move the position inside the tile, we will get a wrong elevation if we have a slope.
   * To catch all cases we round the Z position to the next (TILE_HEIGHT / 2).
   * This will return the correct elevation for slopes and will also detect non-continuous elevation on edges.
   *
   * Also note that the result of GetSlopeZ() is very special on bridge-ramps.
   */

  byte z = GetSlopeZ(TileX(tile) * TILE_SIZE + min(x_pcp_offsets[PCPpos], TILE_SIZE - 1), TileY(tile) * TILE_SIZE + min(y_pcp_offsets[PCPpos], TILE_SIZE - 1));
  return (z + 2) & ~3; // this means z = (z + TILE_HEIGHT / 4) / (TILE_HEIGHT / 2) * (TILE_HEIGHT / 2);
}

void DrawCatenaryOnTunnel(const TileInfo *ti)
{
  /* xmin, ymin, xmax + 1, ymax + 1 of BB */
  static const int _tunnel_wire_BB[4][4] = {
    { 0, 1, 16, 15 }, // NE
    { 1, 0, 15, 16 }, // SE
    { 0, 1, 16, 15 }, // SW
    { 1, 0, 15, 16 }, // NW
  };

  DiagDirection dir = GetTunnelBridgeDirection(ti->tile);

  const SortableSpriteStruct *sss = &CatenarySpriteData_Tunnel[dir];
  const int *BB_data = _tunnel_wire_BB[dir];
  AddSortableSpriteToDraw(
    sss->image, PAL_NONE, ti->x + sss->x_offset, ti->y + sss->y_offset,
    BB_data[2] - sss->x_offset, BB_data[3] - sss->y_offset, BB_Z_SEPARATOR - sss->z_offset + 1,
    GetTileZ(ti->tile) + sss->z_offset,
    IsTransparencySet(TO_CATENARY),
    BB_data[0] - sss->x_offset, BB_data[1] - sss->y_offset, BB_Z_SEPARATOR - sss->z_offset
  );
}

static void DrawCatenaryRailway(const TileInfo *ti)
{
  /* Pylons are placed on a tile edge, so we need to take into account
   * the track configuration of 2 adjacent tiles. trackconfig[0] stores the
   * current tile (home tile) while [1] holds the neighbour */
  TrackBits trackconfig[TS_END];
  bool isflat[TS_END];
  /* Note that ti->tileh has already been adjusted for Foundations */
  Slope tileh[TS_END] = { ti->tileh, SLOPE_FLAT };

  /* Half tile slopes coincide only with horizontal/vertical track.
   * Faking a flat slope results in the correct sprites on positions. */
  if (IsHalftileSlope(tileh[TS_HOME])) tileh[TS_HOME] = SLOPE_FLAT;

  TLG tlg = GetTLG(ti->tile);
  byte PCPstatus = 0;
  byte OverridePCP = 0;
  byte PPPpreferred[DIAGDIR_END];
  byte PPPallowed[DIAGDIR_END];

  /* Find which rail bits are present, and select the override points.
   * We don't draw a pylon:
   * 1) INSIDE a tunnel (we wouldn't see it anyway)
   * 2) on the "far" end of a bridge head (the one that connects to bridge middle),
   *    because that one is drawn on the bridge. Exception is for length 0 bridges
   *    which have no middle tiles */
  trackconfig[TS_HOME] = GetRailTrackBitsUniversal(ti->tile, &OverridePCP);
  /* If a track bit is present that is not in the main direction, the track is level */
  isflat[TS_HOME] = ((trackconfig[TS_HOME] & (TRACK_BIT_HORZ | TRACK_BIT_VERT)) != 0);

  AdjustTileh(ti->tile, &tileh[TS_HOME]);

  for (DiagDirection i = DIAGDIR_NE; i < DIAGDIR_END; i++) {
    TileIndex neighbour = ti->tile + TileOffsByDiagDir(i);
    Foundation foundation = FOUNDATION_NONE;
    byte elevation = GetPCPElevation(ti->tile, i);

    /* Here's one of the main headaches. GetTileSlope does not correct for possibly
     * existing foundataions, so we do have to do that manually later on.*/
    tileh[TS_NEIGHBOUR] = GetTileSlope(neighbour, NULL);
    trackconfig[TS_NEIGHBOUR] = GetRailTrackBitsUniversal(neighbour, NULL);
    if (IsTunnelTile(neighbour) && i != GetTunnelBridgeDirection(neighbour)) trackconfig[TS_NEIGHBOUR] = TRACK_BIT_NONE;

    /* If the neighboured tile does not smoothly connect to the current tile (because of a foundation),
     * we have to draw all pillars on the current tile. */
    if (elevation != GetPCPElevation(neighbour, ReverseDiagDir(i))) trackconfig[TS_NEIGHBOUR] = TRACK_BIT_NONE;

    isflat[TS_NEIGHBOUR] = ((trackconfig[TS_NEIGHBOUR] & (TRACK_BIT_HORZ | TRACK_BIT_VERT)) != 0);

    PPPpreferred[i] = 0xFF; // We start with preferring everything (end-of-line in any direction)
    PPPallowed[i] = AllowedPPPonPCP[i];

    /* We cycle through all the existing tracks at a PCP and see what
     * PPPs we want to have, or may not have at all */
    for (uint k = 0; k < NUM_TRACKS_AT_PCP; k++) {
      /* Next to us, we have a bridge head, don't worry about that one, if it shows away from us */
      if (TrackSourceTile[i][k] == TS_NEIGHBOUR &&
          IsBridgeTile(neighbour) &&
          GetTunnelBridgeDirection(neighbour) == ReverseDiagDir(i)) {
        continue;
      }

      /* We check whether the track in question (k) is present in the tile
       * (TrackSourceTile) */
      if (HasBit(trackconfig[TrackSourceTile[i][k]], TracksAtPCP[i][k])) {
        /* track found, if track is in the neighbour tile, adjust the number
         * of the PCP for preferred/allowed determination*/
        DiagDirection PCPpos = (TrackSourceTile[i][k] == TS_HOME) ? i : ReverseDiagDir(i);
        SetBit(PCPstatus, i); // This PCP is in use

        PPPpreferred[i] &= PreferredPPPofTrackAtPCP[TracksAtPCP[i][k]][PCPpos];
        PPPallowed[i] &= ~DisallowedPPPofTrackAtPCP[TracksAtPCP[i][k]][PCPpos];
      }
    }

    /* Deactivate all PPPs if PCP is not used */
    if (!HasBit(PCPstatus, i)) {
      PPPpreferred[i] = 0;
      PPPallowed[i] = 0;
    }

    /* A station is always "flat", so adjust the tileh accordingly */
    if (IsTileType(neighbour, MP_STATION)) tileh[TS_NEIGHBOUR] = SLOPE_FLAT;

    /* Read the foundataions if they are present, and adjust the tileh */
    if (trackconfig[TS_NEIGHBOUR] != TRACK_BIT_NONE && IsTileType(neighbour, MP_RAILWAY) && HasCatenary(GetRailType(neighbour))) foundation = GetRailFoundation(tileh[TS_NEIGHBOUR], trackconfig[TS_NEIGHBOUR]);
    if (IsBridgeTile(neighbour)) {
      foundation = GetBridgeFoundation(tileh[TS_NEIGHBOUR], DiagDirToAxis(GetTunnelBridgeDirection(neighbour)));
    }

    ApplyFoundationToSlope(foundation, &tileh[TS_NEIGHBOUR]);

    /* Half tile slopes coincide only with horizontal/vertical track.
     * Faking a flat slope results in the correct sprites on positions. */
    if (IsHalftileSlope(tileh[TS_NEIGHBOUR])) tileh[TS_NEIGHBOUR] = SLOPE_FLAT;

    AdjustTileh(neighbour, &tileh[TS_NEIGHBOUR]);

    /* If we have a straight (and level) track, we want a pylon only every 2 tiles
     * Delete the PCP if this is the case. */
    /* Level means that the slope is the same, or the track is flat */
    if (tileh[TS_HOME] == tileh[TS_NEIGHBOUR] || (isflat[TS_HOME] && isflat[TS_NEIGHBOUR])) {
      for (uint k = 0; k < NUM_IGNORE_GROUPS; k++) {
        if (PPPpreferred[i] == IgnoredPCP[k][tlg][i]) ClrBit(PCPstatus, i);
      }
    }

    /* Now decide where we draw our pylons. First try the preferred PPPs, but they may not exist.
     * In that case, we try the any of the allowed ones. if they don't exist either, don't draw
     * anything. Note that the preferred PPPs still contain the end-of-line markers.
     * Remove those (simply by ANDing with allowed, since these markers are never allowed) */
    if ((PPPallowed[i] & PPPpreferred[i]) != 0) PPPallowed[i] &= PPPpreferred[i];

    if (MayHaveBridgeAbove(ti->tile) && IsBridgeAbove(ti->tile)) {
      Track bridgetrack = GetBridgeAxis(ti->tile) == AXIS_X ? TRACK_X : TRACK_Y;
      uint height = GetBridgeHeight(GetNorthernBridgeEnd(ti->tile));

      if ((height <= GetTileMaxZ(ti->tile) + TILE_HEIGHT) &&
          (i == PCPpositions[bridgetrack][0] || i == PCPpositions[bridgetrack][1])) {
        SetBit(OverridePCP, i);
      }
    }

    if (PPPallowed[i] != 0 && HasBit(PCPstatus, i) && !HasBit(OverridePCP, i)) {
      for (Direction k = DIR_BEGIN; k < DIR_END; k++) {
        byte temp = PPPorder[i][GetTLG(ti->tile)][k];

        if (HasBit(PPPallowed[i], temp)) {
          uint x  = ti->x + x_pcp_offsets[i] + x_ppp_offsets[temp];
          uint y  = ti->y + y_pcp_offsets[i] + y_ppp_offsets[temp];

          /* Don't build the pylon if it would be outside the tile */
          if (!HasBit(OwnedPPPonPCP[i], temp)) {
            /* We have a neighour that will draw it, bail out */
            if (trackconfig[TS_NEIGHBOUR] != 0) break;
            continue; /* No neighbour, go looking for a better position */
          }

          AddSortableSpriteToDraw(pylon_sprites[temp], PAL_NONE, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE,
            elevation, IsTransparencySet(TO_CATENARY), -1, -1);

          break; /* We already have drawn a pylon, bail out */
        }
      }
    }
  }

  /* The wire above the tunnel is drawn together with the tunnel-roof (see DrawCatenaryOnTunnel()) */
  if (IsTunnelTile(ti->tile)) return;

  /* Don't draw a wire under a low bridge */
  if (MayHaveBridgeAbove(ti->tile) && IsBridgeAbove(ti->tile) && !IsTransparencySet(TO_CATENARY)) {
    uint height = GetBridgeHeight(GetNorthernBridgeEnd(ti->tile));

    if (height <= GetTileMaxZ(ti->tile) + TILE_HEIGHT) return;
  }

  /* Drawing of pylons is finished, now draw the wires */
  for (Track t = TRACK_BEGIN; t < TRACK_END; t++) {
    if (HasBit(trackconfig[TS_HOME], t)) {
      byte PCPconfig = HasBit(PCPstatus, PCPpositions[t][0]) +
        (HasBit(PCPstatus, PCPpositions[t][1]) << 1);

      const SortableSpriteStruct *sss;
      int tileh_selector = !(tileh[TS_HOME] % 3) * tileh[TS_HOME] / 3; /* tileh for the slopes, 0 otherwise */

      assert(PCPconfig != 0); /* We have a pylon on neither end of the wire, that doesn't work (since we have no sprites for that) */
      assert(!IsSteepSlope(tileh[TS_HOME]));
      sss = &CatenarySpriteData[Wires[tileh_selector][t][PCPconfig]];

      /*
       * The "wire"-sprite position is inside the tile, i.e. 0 <= sss->?_offset < TILE_SIZE.
       * Therefore it is safe to use GetSlopeZ() for the elevation.
       * Also note, that the result of GetSlopeZ() is very special for bridge-ramps.
       */
      AddSortableSpriteToDraw(sss->image, PAL_NONE, ti->x + sss->x_offset, ti->y + sss->y_offset,
        sss->x_size, sss->y_size, sss->z_size, GetSlopeZ(ti->x + sss->x_offset, ti->y + sss->y_offset) + sss->z_offset,
        IsTransparencySet(TO_CATENARY));
    }
  }
}

void DrawCatenaryOnBridge(const TileInfo *ti)
{
  TileIndex end = GetSouthernBridgeEnd(ti->tile);
  TileIndex start = GetOtherBridgeEnd(end);

  uint length = GetTunnelBridgeLength(start, end);
  uint num = GetTunnelBridgeLength(ti->tile, start) + 1;
  uint height;

  const SortableSpriteStruct *sss;
  Axis axis = GetBridgeAxis(ti->tile);
  TLG tlg = GetTLG(ti->tile);

  CatenarySprite offset = (CatenarySprite)(axis == AXIS_X ? 0 : WIRE_Y_FLAT_BOTH - WIRE_X_FLAT_BOTH);

  if ((length % 2) && num == length) {
    /* Draw the "short" wire on the southern end of the bridge
     * only needed if the length of the bridge is odd */
    sss = &CatenarySpriteData[WIRE_X_FLAT_BOTH + offset];
  } else {
    /* Draw "long" wires on all other tiles of the bridge (one pylon every two tiles) */
    sss = &CatenarySpriteData[WIRE_X_FLAT_SW + (num % 2) + offset];
  }

  height = GetBridgeHeight(end);

  AddSortableSpriteToDraw(sss->image, PAL_NONE, ti->x + sss->x_offset, ti->y + sss->y_offset,
    sss->x_size, sss->y_size, sss->z_size, height + sss->z_offset,
    IsTransparencySet(TO_CATENARY)
  );

  /* Finished with wires, draw pylons */
  /* every other tile needs a pylon on the northern end */
  if (num % 2) {
    DiagDirection PCPpos = (axis == AXIS_X ? DIAGDIR_NE : DIAGDIR_NW);
    Direction PPPpos = (axis == AXIS_X ? DIR_NW : DIR_NE);
    if (HasBit(tlg, (axis == AXIS_X ? 0 : 1))) PPPpos = ReverseDir(PPPpos);
    uint x = ti->x + x_pcp_offsets[PCPpos] + x_ppp_offsets[PPPpos];
    uint y = ti->y + y_pcp_offsets[PCPpos] + y_ppp_offsets[PPPpos];
    AddSortableSpriteToDraw(pylon_sprites[PPPpos], PAL_NONE, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE, height, IsTransparencySet(TO_CATENARY), -1, -1);
  }

  /* need a pylon on the southern end of the bridge */
  if (GetTunnelBridgeLength(ti->tile, start) + 1 == length) {
    DiagDirection PCPpos = (axis == AXIS_X ? DIAGDIR_SW : DIAGDIR_SE);
    Direction PPPpos = (axis == AXIS_X ? DIR_NW : DIR_NE);
    if (HasBit(tlg, (axis == AXIS_X ? 0 : 1))) PPPpos = ReverseDir(PPPpos);
    uint x = ti->x + x_pcp_offsets[PCPpos] + x_ppp_offsets[PPPpos];
    uint y = ti->y + y_pcp_offsets[PCPpos] + y_ppp_offsets[PPPpos];
    AddSortableSpriteToDraw(pylon_sprites[PPPpos], PAL_NONE, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE, height, IsTransparencySet(TO_CATENARY), -1, -1);
  }
}

void DrawCatenary(const TileInfo *ti)
{
  switch (GetTileType(ti->tile)) {
    case MP_RAILWAY:
      if (IsRailDepot(ti->tile)) {
        const SortableSpriteStruct *sss = &CatenarySpriteData_Depot[GetRailDepotDirection(ti->tile)];

        /* This wire is not visible with the default depot sprites */
        AddSortableSpriteToDraw(
          sss->image, PAL_NONE, ti->x + sss->x_offset, ti->y + sss->y_offset,
          sss->x_size, sss->y_size, sss->z_size,
          GetTileMaxZ(ti->tile) + sss->z_offset,
          IsTransparencySet(TO_CATENARY)
        );
        return;
      }
      break;

    case MP_TUNNELBRIDGE:
    case MP_ROAD:
    case MP_STATION:
      break;

    default: return;
  }
  DrawCatenaryRailway(ti);
}

int32 SettingsDisableElrail(int32 p1)
{
  Vehicle *v;
  Company *c;
  bool disable = (p1 != 0);

  /* we will now walk through all electric train engines and change their railtypes if it is the wrong one*/
  const RailType old_railtype = disable ? RAILTYPE_ELECTRIC : RAILTYPE_RAIL;
  const RailType new_railtype = disable ? RAILTYPE_RAIL : RAILTYPE_ELECTRIC;

  /* walk through all train engines */
  Engine *e;
  FOR_ALL_ENGINES_OF_TYPE(e, VEH_TRAIN) {
    RailVehicleInfo *rv_info = &e->u.rail;
    /* if it is an electric rail engine and its railtype is the wrong one */
    if (rv_info->engclass == 2 && rv_info->railtype == old_railtype) {
      /* change it to the proper one */
      rv_info->railtype = new_railtype;
    }
  }

  /* when disabling elrails, make sure that all existing trains can run on
  *  normal rail too */
  if (disable) {
    FOR_ALL_VEHICLES(v) {
      if (v->type == VEH_TRAIN && v->u.rail.railtype == RAILTYPE_ELECTRIC) {
        /* this railroad vehicle is now compatible only with elrail,
        *  so add there also normal rail compatibility */
        v->u.rail.compatible_railtypes |= RAILTYPES_RAIL;
        v->u.rail.railtype = RAILTYPE_RAIL;
        SetBit(v->u.rail.flags, VRF_EL_ENGINE_ALLOWED_NORMAL_RAIL);
      }
    }
  }

  /* Fix the total power and acceleration for trains */
  FOR_ALL_VEHICLES(v) {
    /* power and acceleration is cached only for front engines */
    if (v->type == VEH_TRAIN && IsFrontEngine(v)) {
      TrainPowerChanged(v);
      UpdateTrainAcceleration(v);
    }
  }

  FOR_ALL_COMPANIES(c) c->avail_railtypes = GetCompanyRailtypes(c->index);

  /* This resets the _last_built_railtype, which will be invalid for electric
  * rails. It may have unintended consequences if that function is ever
  * extended, though. */
  ReinitGuiAfterToggleElrail(disable);
  return 0;
}