OpenTTD
Functions
elrail.cpp File Reference

This file deals with displaying wires and pylons for electric railways. More...

#include "stdafx.h"
#include "station_map.h"
#include "viewport_func.h"
#include "train.h"
#include "rail_gui.h"
#include "tunnelbridge_map.h"
#include "tunnelbridge.h"
#include "elrail_func.h"
#include "company_base.h"
#include "newgrf_railtype.h"
#include "table/elrail_data.h"
#include "safeguards.h"

Go to the source code of this file.

Functions

static TLG GetTLG (TileIndex t)
 Get the tile location group of a tile. More...
 
static TrackBits GetRailTrackBitsUniversal (TileIndex t, byte *override)
 Finds which Electrified Rail Bits are present on a given tile. More...
 
static TrackBits MaskWireBits (TileIndex t, TrackBits tracks)
 Masks out track bits when neighbouring tiles are unelectrified.
 
static SpriteID GetWireBase (TileIndex tile, TileContext context=TCX_NORMAL)
 Get the base wire sprite to use.
 
static SpriteID GetPylonBase (TileIndex tile, TileContext context=TCX_NORMAL)
 Get the base pylon sprite to use.
 
static void AdjustTileh (TileIndex tile, Slope *tileh)
 Corrects the tileh for certain tile types. More...
 
static int GetPCPElevation (TileIndex tile, DiagDirection PCPpos)
 Returns the Z position of a Pylon Control Point. More...
 
void DrawRailCatenaryOnTunnel (const TileInfo *ti)
 Draws wires on a tunnel tile. More...
 
static void DrawRailCatenaryRailway (const TileInfo *ti)
 Draws wires and, if required, pylons on a given tile. More...
 
void DrawRailCatenaryOnBridge (const TileInfo *ti)
 Draws wires on a tunnel tile. More...
 
void DrawRailCatenary (const TileInfo *ti)
 Draws overhead wires and pylons for electric railways. More...
 
bool SettingsDisableElrail (int32 p1)
 _settings_game.disable_elrail callback
 

Detailed Description

This file deals with displaying wires and pylons for electric railways.

Basics

Tile Types

We have two different types of tiles in the drawing code: Normal Railway Tiles (NRTs) which can have more than one track on it, and Special Railways tiles (SRTs) which have only one track (like crossings, depots stations, etc).

Location Categories

All tiles are categorized into three location groups (TLG): Group 0: Tiles with both an even X coordinate and an even Y coordinate Group 1: Tiles with an even X and an odd Y coordinate Group 2: Tiles with an odd X and an even Y coordinate Group 3: Tiles with both an odd X and Y coordinate.

Pylon Points

Control Points

A Pylon Control Point (PCP) is a position where a wire (or rather two) is mounted onto a pylon. Each NRT does contain 4 PCPs which are bitmapped to a byte variable and are represented by the DiagDirection enum

Each track ends on two PCPs and thus requires one pylon on each end. However, there is one exception: Straight-and-level tracks only have one pylon every other tile.

Now on each edge there are two PCPs: One from each adjacent tile. Both PCPs are merged using an OR operation (i. e. if one tile needs a PCP at the position in question, both tiles get it).

Position Points

A Pylon Position Point (PPP) is a position where a pylon is located on the ground. Each PCP owns 8 in (45 degree steps) PPPs that are located around it. PPPs are represented using the Direction enum. Each track bit has PPPs that are impossible (because the pylon would be situated on the track) and some that are preferred (because the pylon would be rectangular to the track).

elrail_tile.png
elrail_track.png

Definition in file elrail.cpp.

Function Documentation

◆ AdjustTileh()

static void AdjustTileh ( TileIndex  tile,
Slope tileh 
)
static

Corrects the tileh for certain tile types.

Returns an effective tileh for the track on the tile.

Parameters
tileThe tile to analyse
*tilehthe tileh

Definition at line 198 of file elrail.cpp.

References GetTunnelBridgeDirection(), InclinedSlope(), IsTileType(), IsTunnel(), MP_TUNNELBRIDGE, SLOPE_FLAT, and SLOPE_STEEP.

◆ DrawRailCatenary()

void DrawRailCatenary ( const TileInfo ti)

Draws overhead wires and pylons for electric railways.

Parameters
tiThe TileInfo struct of the tile being drawn
See also
DrawRailCatenaryRailway

Definition at line 564 of file elrail.cpp.

References GetTileType(), IsRailDepot(), MP_RAILWAY, and TileInfo::tile.

Referenced by HasRailCatenaryDrawn().

◆ DrawRailCatenaryOnBridge()

void DrawRailCatenaryOnBridge ( const TileInfo ti)

Draws wires on a tunnel tile.

DrawTile_TunnelBridge() calls this function to draw the wires on the bridge.

Parameters
tiThe Tileinfo to draw the tile for

Definition at line 502 of file elrail.cpp.

References GetOtherBridgeEnd(), GetSouthernBridgeEnd(), GetTunnelBridgeLength(), and TileInfo::tile.

Referenced by HasRailCatenaryDrawn().

◆ DrawRailCatenaryOnTunnel()

void DrawRailCatenaryOnTunnel ( const TileInfo ti)

Draws wires on a tunnel tile.

DrawTile_TunnelBridge() calls this function to draw the wires as SpriteCombine with the tunnel roof.

Parameters
tiThe Tileinfo to draw the tile for

Definition at line 245 of file elrail.cpp.

References GetTunnelBridgeDirection(), GetWireBase(), and TileInfo::tile.

Referenced by HasRailCatenaryDrawn().

◆ DrawRailCatenaryRailway()

static void DrawRailCatenaryRailway ( const TileInfo ti)
static

Draws wires and, if required, pylons on a given tile.

Parameters
tiThe Tileinfo to draw the tile for

Definition at line 274 of file elrail.cpp.

◆ GetPCPElevation()

static int GetPCPElevation ( TileIndex  tile,
DiagDirection  PCPpos 
)
static

Returns the Z position of a Pylon Control Point.

Parameters
tileThe tile the pylon should stand on.
PCPposThe PCP of the tile.
Returns
The Z position of the PCP.

Definition at line 218 of file elrail.cpp.

◆ GetRailTrackBitsUniversal()

static TrackBits GetRailTrackBitsUniversal ( TileIndex  t,
byte *  override 
)
static

◆ GetTLG()

static TLG GetTLG ( TileIndex  t)
inlinestatic

Get the tile location group of a tile.

Parameters
tThe tile to get the tile location group of.
Returns
The tile location group.

Definition at line 77 of file elrail.cpp.

References HasBit(), TileX(), and TileY().