--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/bridge_cmd.cpp Thu Jan 11 13:41:16 2007 +0000
@@ -0,0 +1,1085 @@
+/* $Id$ */
+
+/** @file bridge_cmd.c
+ * This file deals with tunnels and bridges (non-gui stuff)
+ * @todo seperate this file into two
+ */
+
+#include "stdafx.h"
+#include "openttd.h"
+#include "bridge_map.h"
+#include "rail_map.h"
+#include "road_map.h"
+#include "table/sprites.h"
+#include "table/strings.h"
+#include "functions.h"
+#include "map.h"
+#include "tile.h"
+#include "tunnel_map.h"
+#include "unmovable_map.h"
+#include "vehicle.h"
+#include "viewport.h"
+#include "command.h"
+#include "player.h"
+#include "town.h"
+#include "sound.h"
+#include "variables.h"
+#include "bridge.h"
+#include "train.h"
+#include "water_map.h"
+#include "yapf/yapf.h"
+#include "date.h"
+#include "newgrf_sound.h"
+
+#include "table/bridge_land.h"
+
+const Bridge orig_bridge[] = {
+/*
+ year of availablity
+ | minimum length
+ | | maximum length
+ | | | price
+ | | | | maximum speed
+ | | | | | sprite to use in GUI string with description
+ | | | | | | | */
+ { 0, 0, 16, 80, 32, 0xA24 , STR_5012_WOODEN , NULL, 0 },
+ { 0, 0, 2, 112, 48, 0xA26 | PALETTE_TO_STRUCT_RED , STR_5013_CONCRETE , NULL, 0 },
+ { 1930, 0, 5, 144, 64, 0xA25 , STR_500F_GIRDER_STEEL , NULL, 0 },
+ { 0, 2, 10, 168, 80, 0xA22 | PALETTE_TO_STRUCT_CONCRETE, STR_5011_SUSPENSION_CONCRETE, NULL, 0 },
+ { 1930, 3, 16, 185, 96, 0xA22 , STR_500E_SUSPENSION_STEEL , NULL, 0 },
+ { 1930, 3, 16, 192, 112, 0xA22 | PALETTE_TO_STRUCT_YELLOW , STR_500E_SUSPENSION_STEEL , NULL, 0 },
+ { 1930, 3, 7, 224, 160, 0xA23 , STR_5010_CANTILEVER_STEEL , NULL, 0 },
+ { 1930, 3, 8, 232, 208, 0xA23 | PALETTE_TO_STRUCT_BROWN , STR_5010_CANTILEVER_STEEL , NULL, 0 },
+ { 1930, 3, 9, 248, 240, 0xA23 | PALETTE_TO_STRUCT_RED , STR_5010_CANTILEVER_STEEL , NULL, 0 },
+ { 1930, 0, 2, 240, 256, 0xA27 , STR_500F_GIRDER_STEEL , NULL, 0 },
+ { 1995, 2, 16, 255, 320, 0xA28 , STR_5014_TUBULAR_STEEL , NULL, 0 },
+ { 2005, 2, 32, 380, 512, 0xA28 | PALETTE_TO_STRUCT_YELLOW , STR_5014_TUBULAR_STEEL , NULL, 0 },
+ { 2010, 2, 32, 510, 608, 0xA28 | PALETTE_TO_STRUCT_GREY , STR_BRIDGE_TUBULAR_SILICON , NULL, 0 }
+};
+
+Bridge _bridge[MAX_BRIDGES];
+
+
+// calculate the price factor for building a long bridge.
+// basically the cost delta is 1,1, 1, 2,2, 3,3,3, 4,4,4,4, 5,5,5,5,5, 6,6,6,6,6,6, 7,7,7,7,7,7,7, 8,8,8,8,8,8,8,8,
+int CalcBridgeLenCostFactor(int x)
+{
+ int n;
+ int r;
+
+ if (x < 2) return x;
+ x -= 2;
+ for (n = 0, r = 2;; n++) {
+ if (x <= n) return r + x * n;
+ r += n * n;
+ x -= n;
+ }
+}
+
+static inline const PalSpriteID *GetBridgeSpriteTable(int index, byte table)
+{
+ const Bridge *bridge = &_bridge[index];
+ assert(table < 7);
+ if (bridge->sprite_table == NULL || bridge->sprite_table[table] == NULL) {
+ return _bridge_sprite_table[index][table];
+ } else {
+ return bridge->sprite_table[table];
+ }
+}
+
+static inline byte GetBridgeFlags(int index) { return _bridge[index].flags;}
+
+
+/** Check the slope at the bridge ramps in three easy steps:
+ * - valid slopes without foundation
+ * - valid slopes with foundation
+ * - rest is invalid
+ */
+#define M(x) (1 << (x))
+static int32 CheckBridgeSlopeNorth(Axis axis, Slope tileh)
+{
+ uint32 valid;
+
+ valid = M(SLOPE_FLAT) | (axis == AXIS_X ? M(SLOPE_NE) : M(SLOPE_NW));
+ if (HASBIT(valid, tileh)) return 0;
+
+ valid =
+ BRIDGE_FULL_LEVELED_FOUNDATION | M(SLOPE_N) | M(SLOPE_STEEP_N) |
+ (axis == AXIS_X ? M(SLOPE_E) | M(SLOPE_STEEP_E) : M(SLOPE_W) | M(SLOPE_STEEP_W));
+ if (HASBIT(valid, tileh)) return _price.terraform;
+
+ return CMD_ERROR;
+}
+
+static int32 CheckBridgeSlopeSouth(Axis axis, Slope tileh)
+{
+ uint32 valid;
+
+ valid = M(SLOPE_FLAT) | (axis == AXIS_X ? M(SLOPE_SW) : M(SLOPE_SE));
+ if (HASBIT(valid, tileh)) return 0;
+
+ valid =
+ BRIDGE_FULL_LEVELED_FOUNDATION | M(SLOPE_S) | M(SLOPE_STEEP_S) |
+ (axis == AXIS_X ? M(SLOPE_W) | M(SLOPE_STEEP_W) : M(SLOPE_E) | M(SLOPE_STEEP_E));
+ if (HASBIT(valid, tileh)) return _price.terraform;
+
+ return CMD_ERROR;
+}
+#undef M
+
+
+uint32 GetBridgeLength(TileIndex begin, TileIndex end)
+{
+ int x1 = TileX(begin);
+ int y1 = TileY(begin);
+ int x2 = TileX(end);
+ int y2 = TileY(end);
+
+ return abs(x2 + y2 - x1 - y1) - 1;
+}
+
+bool CheckBridge_Stuff(byte bridge_type, uint bridge_len)
+{
+ const Bridge *b = &_bridge[bridge_type];
+ uint max; // max possible length of a bridge (with patch 100)
+
+ if (bridge_type >= MAX_BRIDGES) return false;
+ if (b->avail_year > _cur_year) return false;
+
+ max = b->max_length;
+ if (max >= 16 && _patches.longbridges) max = 100;
+
+ return b->min_length <= bridge_len && bridge_len <= max;
+}
+
+/** Build a Bridge
+ * @param end_tile end tile
+ * @param p1 packed start tile coords (~ dx)
+ * @param p2 various bitstuffed elements
+ * - p2 = (bit 0- 7) - bridge type (hi bh)
+ * - p2 = (bit 8-..) - rail type. bit15 ((x>>8)&0x80) means road bridge.
+ */
+int32 CmdBuildBridge(TileIndex end_tile, uint32 flags, uint32 p1, uint32 p2)
+{
+ int bridge_type;
+ TransportType transport;
+ RailType railtype;
+ uint x;
+ uint y;
+ uint sx;
+ uint sy;
+ TileIndex tile_start;
+ TileIndex tile_end;
+ Slope tileh_start;
+ Slope tileh_end;
+ uint z_start;
+ uint z_end;
+ TileIndex tile;
+ TileIndexDiff delta;
+ uint bridge_len;
+ Axis direction;
+ int32 cost, terraformcost, ret;
+ bool allow_on_slopes;
+
+ SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
+
+ /* unpack parameters */
+ bridge_type = GB(p2, 0, 8);
+
+ if (p1 >= MapSize()) return CMD_ERROR;
+
+ // type of bridge
+ if (HASBIT(p2, 15)) {
+ railtype = 0;
+ transport = TRANSPORT_ROAD;
+ } else {
+ if (!ValParamRailtype(GB(p2, 8, 8))) return CMD_ERROR;
+ railtype = GB(p2, 8, 8);
+ transport = TRANSPORT_RAIL;
+ }
+
+ x = TileX(end_tile);
+ y = TileY(end_tile);
+ sx = TileX(p1);
+ sy = TileY(p1);
+
+ /* check if valid, and make sure that (x,y) are smaller than (sx,sy) */
+ if (x == sx) {
+ if (y == sy) return_cmd_error(STR_5008_CANNOT_START_AND_END_ON);
+ direction = AXIS_Y;
+ if (y > sy) uintswap(y,sy);
+ } else if (y == sy) {
+ direction = AXIS_X;
+ if (x > sx) uintswap(x,sx);
+ } else {
+ return_cmd_error(STR_500A_START_AND_END_MUST_BE_IN);
+ }
+
+ /* set and test bridge length, availability */
+ bridge_len = sx + sy - x - y - 1;
+ if (!CheckBridge_Stuff(bridge_type, bridge_len)) return_cmd_error(STR_5015_CAN_T_BUILD_BRIDGE_HERE);
+
+ /* retrieve landscape height and ensure it's on land */
+ tile_start = TileXY(x, y);
+ tile_end = TileXY(sx, sy);
+ if (IsClearWaterTile(tile_start) || IsClearWaterTile(tile_end)) {
+ return_cmd_error(STR_02A0_ENDS_OF_BRIDGE_MUST_BOTH);
+ }
+
+ tileh_start = GetTileSlope(tile_start, &z_start);
+ tileh_end = GetTileSlope(tile_end, &z_end);
+
+ if (IsSteepSlope(tileh_start)) z_start += TILE_HEIGHT;
+ if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh_start)) {
+ z_start += TILE_HEIGHT;
+ tileh_start = SLOPE_FLAT;
+ }
+
+ if (IsSteepSlope(tileh_end)) z_end += TILE_HEIGHT;
+ if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh_end)) {
+ z_end += TILE_HEIGHT;
+ tileh_end = SLOPE_FLAT;
+ }
+
+ if (z_start != z_end) return_cmd_error(STR_5009_LEVEL_LAND_OR_WATER_REQUIRED);
+
+ // Towns are not allowed to use bridges on slopes.
+ allow_on_slopes = (!_is_old_ai_player
+ && _current_player != OWNER_TOWN && _patches.build_on_slopes);
+
+ /* Try and clear the start landscape */
+
+ ret = DoCommand(tile_start, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
+ if (CmdFailed(ret)) return ret;
+ cost = ret;
+
+ terraformcost = CheckBridgeSlopeNorth(direction, tileh_start);
+ if (CmdFailed(terraformcost) || (terraformcost != 0 && !allow_on_slopes))
+ return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
+ cost += terraformcost;
+
+ /* Try and clear the end landscape */
+
+ ret = DoCommand(tile_end, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
+ if (CmdFailed(ret)) return ret;
+ cost += ret;
+
+ // false - end tile slope check
+ terraformcost = CheckBridgeSlopeSouth(direction, tileh_end);
+ if (CmdFailed(terraformcost) || (terraformcost != 0 && !allow_on_slopes))
+ return_cmd_error(STR_1000_LAND_SLOPED_IN_WRONG_DIRECTION);
+ cost += terraformcost;
+
+ {
+ TileIndex Heads[] = {tile_start, tile_end};
+ int i;
+
+ for (i = 0; i < 2; i++) {
+ if (MayHaveBridgeAbove(Heads[i])) {
+ if (IsBridgeAbove(Heads[i])) {
+ TileIndex north_head = GetNorthernBridgeEnd(Heads[i]);
+
+ if (direction == GetBridgeAxis(Heads[i])) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
+
+ if (z_start + TILE_HEIGHT == GetBridgeHeight(north_head)) {
+ return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
+ }
+ }
+ }
+ }
+ }
+
+ /* do the drill? */
+ if (flags & DC_EXEC) {
+ DiagDirection dir = AxisToDiagDir(direction);
+
+ if (transport == TRANSPORT_RAIL) {
+ MakeRailBridgeRamp(tile_start, _current_player, bridge_type, dir, railtype);
+ MakeRailBridgeRamp(tile_end, _current_player, bridge_type, ReverseDiagDir(dir), railtype);
+ } else {
+ MakeRoadBridgeRamp(tile_start, _current_player, bridge_type, dir);
+ MakeRoadBridgeRamp(tile_end, _current_player, bridge_type, ReverseDiagDir(dir));
+ }
+ MarkTileDirtyByTile(tile_start);
+ MarkTileDirtyByTile(tile_end);
+ }
+
+ delta = (direction == AXIS_X ? TileDiffXY(1, 0) : TileDiffXY(0, 1));
+ for (tile = tile_start + delta; tile != tile_end; tile += delta) {
+ uint z;
+
+ if (GetTileSlope(tile, &z) != SLOPE_FLAT && z >= z_start) return_cmd_error(STR_5009_LEVEL_LAND_OR_WATER_REQUIRED);
+
+ if (MayHaveBridgeAbove(tile) && IsBridgeAbove(tile)) {
+ /* Disallow crossing bridges for the time being */
+ return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
+ }
+
+ switch (GetTileType(tile)) {
+ case MP_WATER:
+ if (!EnsureNoVehicle(tile)) return_cmd_error(STR_980E_SHIP_IN_THE_WAY);
+ if (!IsWater(tile) && !IsCoast(tile)) goto not_valid_below;
+ break;
+
+ case MP_RAILWAY:
+ if (!IsPlainRailTile(tile)) goto not_valid_below;
+ break;
+
+ case MP_STREET:
+ if (GetRoadTileType(tile) == ROAD_TILE_DEPOT) goto not_valid_below;
+ break;
+
+ case MP_TUNNEL:
+ break;
+
+ case MP_STREET_BRIDGE:
+ case MP_RAILWAY_BRIDGE:
+ if (direction == DiagDirToAxis(GetBridgeRampDirection(tile))) goto not_valid_below;
+ if (z_start < GetBridgeHeight(tile)) goto not_valid_below;
+ break;
+
+ case MP_UNMOVABLE:
+ if (!IsOwnedLand(tile)) goto not_valid_below;
+ break;
+
+ case MP_CLEAR:
+ if (IsBridgeAbove(tile)) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
+ break;
+
+ default:
+not_valid_below:;
+ /* try and clear the middle landscape */
+ ret = DoCommand(tile, 0, 0, flags, CMD_LANDSCAPE_CLEAR);
+ if (CmdFailed(ret)) return ret;
+ cost += ret;
+ break;
+ }
+
+ if (flags & DC_EXEC) {
+ SetBridgeMiddle(tile, direction);
+ MarkTileDirtyByTile(tile);
+ }
+ }
+
+ if (flags & DC_EXEC) {
+ Track track = AxisToTrack(direction);
+ SetSignalsOnBothDir(tile_start, track);
+ YapfNotifyTrackLayoutChange(tile_start, track);
+ }
+
+ /* for human player that builds the bridge he gets a selection to choose from bridges (DC_QUERY_COST)
+ * It's unnecessary to execute this command every time for every bridge. So it is done only
+ * and cost is computed in "bridge_gui.c". For AI, Towns this has to be of course calculated
+ */
+ if (!(flags & DC_QUERY_COST)) {
+ const Bridge *b = &_bridge[bridge_type];
+
+ bridge_len += 2; // begin and end tiles/ramps
+
+ if (IsValidPlayer(_current_player) && !_is_old_ai_player)
+ bridge_len = CalcBridgeLenCostFactor(bridge_len);
+
+ cost += (int64)bridge_len * _price.build_bridge * b->price >> 8;
+ }
+
+ return cost;
+}
+
+
+static inline bool CheckAllowRemoveBridge(TileIndex tile)
+{
+ /* Floods can remove anything as well as the scenario editor */
+ if (_current_player == OWNER_WATER || _game_mode == GM_EDITOR) return true;
+ /* Obviously if the bridge/tunnel belongs to us, or no-one, we can remove it */
+ if (CheckTileOwnership(tile) || IsTileOwner(tile, OWNER_NONE)) return true;
+ /* Otherwise we can only remove town-owned stuff with extra patch-settings, or cheat */
+ if (IsTileOwner(tile, OWNER_TOWN) && (_patches.extra_dynamite || _cheats.magic_bulldozer.value)) return true;
+ return false;
+}
+
+static bool IsVehicleOnBridge(TileIndex starttile, TileIndex endtile, uint z)
+{
+ const Vehicle *v;
+ FOR_ALL_VEHICLES(v) {
+ if ((v->tile == starttile || v->tile == endtile) && v->z_pos == z) {
+ _error_message = VehicleInTheWayErrMsg(v);
+ return true;
+ }
+ }
+ return false;
+}
+
+static int32 DoClearBridge(TileIndex tile, uint32 flags)
+{
+ DiagDirection direction;
+ TileIndexDiff delta;
+ TileIndex endtile;
+ Town *t = NULL;
+
+ SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
+
+ if (!CheckAllowRemoveBridge(tile)) return CMD_ERROR;
+
+ endtile = GetOtherBridgeEnd(tile);
+
+ if (!EnsureNoVehicle(tile) ||
+ !EnsureNoVehicle(endtile) ||
+ IsVehicleOnBridge(tile, endtile, GetBridgeHeight(tile))) {
+ return CMD_ERROR;
+ }
+
+ direction = GetBridgeRampDirection(tile);
+ delta = TileOffsByDiagDir(direction);
+
+ if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR) {
+ t = ClosestTownFromTile(tile, (uint)-1); // town penalty rating
+
+ /* Check if you are allowed to remove the bridge owned by a town
+ * Removal depends on difficulty settings */
+ if (!CheckforTownRating(flags, t, TUNNELBRIDGE_REMOVE)) {
+ SetDParam(0, t->index);
+ return_cmd_error(STR_2009_LOCAL_AUTHORITY_REFUSES);
+ }
+ }
+
+ if (flags & DC_EXEC) {
+ TileIndex c;
+ Track track;
+
+ //checks if the owner is town then decrease town rating by RATING_TUNNEL_BRIDGE_DOWN_STEP until
+ // you have a "Poor" (0) town rating
+ if (IsTileOwner(tile, OWNER_TOWN) && _game_mode != GM_EDITOR)
+ ChangeTownRating(t, RATING_TUNNEL_BRIDGE_DOWN_STEP, RATING_TUNNEL_BRIDGE_MINIMUM);
+
+ DoClearSquare(tile);
+ DoClearSquare(endtile);
+ for (c = tile + delta; c != endtile; c += delta) {
+ ClearBridgeMiddle(c);
+ MarkTileDirtyByTile(c);
+ }
+
+ UpdateSignalsOnSegment(tile, ReverseDiagDir(direction));
+ UpdateSignalsOnSegment(endtile, direction);
+ track = AxisToTrack(DiagDirToAxis(direction));
+ YapfNotifyTrackLayoutChange(tile, track);
+ YapfNotifyTrackLayoutChange(endtile, track);
+ }
+
+ return (DistanceManhattan(tile, endtile) + 1) * _price.clear_bridge;
+}
+
+
+static int32 ClearTile_Bridge(TileIndex tile, byte flags)
+{
+ assert(IsBridgeTile(tile));
+ if (flags & DC_AUTO) return_cmd_error(STR_5007_MUST_DEMOLISH_BRIDGE_FIRST);
+ return DoClearBridge(tile, flags);
+}
+
+int32 DoConvertBridgeRail(TileIndex tile, RailType totype, bool exec)
+{
+ TileIndex endtile;
+
+ if (GetBridgeTransportType(tile) == TRANSPORT_RAIL) {
+ if (!CheckTileOwnership(tile)) return CMD_ERROR;
+
+ endtile = GetOtherBridgeEnd(tile);
+
+ if (!EnsureNoVehicle(tile) ||
+ !EnsureNoVehicle(endtile) ||
+ IsVehicleOnBridge(tile, endtile, GetBridgeHeight(tile))) {
+ return CMD_ERROR;
+ }
+
+ if (GetRailType(tile) == totype) return CMD_ERROR;
+
+ if (exec) {
+ TileIndexDiff delta;
+ Track track;
+
+ SetRailType(tile, totype);
+ SetRailType(endtile, totype);
+ MarkTileDirtyByTile(tile);
+ MarkTileDirtyByTile(endtile);
+
+ track = AxisToTrack(DiagDirToAxis(GetBridgeRampDirection(tile)));
+ YapfNotifyTrackLayoutChange(tile, track);
+ YapfNotifyTrackLayoutChange(endtile, track);
+
+ delta = TileOffsByDiagDir(GetBridgeRampDirection(tile));
+ for (tile += delta; tile != endtile; tile += delta) {
+ MarkTileDirtyByTile(tile); // TODO encapsulate this into a function
+ }
+ }
+
+ return (DistanceManhattan(tile, endtile) + 1) * (_price.build_rail >> 1);
+ } else {
+ return CMD_ERROR;
+ }
+}
+
+
+static void DrawBridgePillars(PalSpriteID image, const TileInfo* ti, Axis axis, uint type, int x, int y, int z)
+{
+ if (image != 0) {
+ bool drawfarpillar = !HASBIT(GetBridgeFlags(type), 0);
+ int back_height, front_height;
+ int i = z;
+ const byte *p;
+
+ static const byte _tileh_bits[4][8] = {
+ { 2, 1, 8, 4, 16, 2, 0, 9 },
+ { 1, 8, 4, 2, 2, 16, 9, 0 },
+ { 4, 8, 1, 2, 16, 2, 0, 9 },
+ { 2, 4, 8, 1, 2, 16, 9, 0 }
+ };
+
+ if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
+
+ p = _tileh_bits[(image & 1) * 2 + (axis == AXIS_X ? 0 : 1)];
+ front_height = ti->z + (ti->tileh & p[0] ? TILE_HEIGHT : 0);
+ back_height = ti->z + (ti->tileh & p[1] ? TILE_HEIGHT : 0);
+
+ if (IsSteepSlope(ti->tileh)) {
+ if (!(ti->tileh & p[2])) front_height += TILE_HEIGHT;
+ if (!(ti->tileh & p[3])) back_height += TILE_HEIGHT;
+ }
+
+ for (; z >= front_height || z >= back_height; z -= TILE_HEIGHT) {
+ /* HACK set height of the BB of pillars to 1, because the origin of the
+ * sprites is at the top
+ */
+ if (z >= front_height) { // front facing pillar
+ AddSortableSpriteToDraw(image, x, y, p[4], p[5], 1, z);
+ }
+
+ if (drawfarpillar && z >= back_height && z < i - TILE_HEIGHT) { // back facing pillar
+ AddSortableSpriteToDraw(image, x - p[6], y - p[7], p[4], p[5], 1, z);
+ }
+ }
+ }
+}
+
+uint GetBridgeFoundation(Slope tileh, Axis axis)
+{
+ uint i;
+
+ if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh)) return tileh;
+
+ // inclined sloped building
+ switch (tileh) {
+ case SLOPE_W:
+ case SLOPE_STEEP_W: i = 0; break;
+ case SLOPE_S:
+ case SLOPE_STEEP_S: i = 2; break;
+ case SLOPE_E:
+ case SLOPE_STEEP_E: i = 4; break;
+ case SLOPE_N:
+ case SLOPE_STEEP_N: i = 6; break;
+ default: return 0;
+ }
+ if (axis != AXIS_X) ++i;
+ return i + 15;
+}
+
+
+/**
+ * Draws a bridge tile.
+ * base_offset is where the sprite selection comes into play
+ * and it works a bit like a bitmask.<p> For bridge heads:
+ * <ul><li>Bit 0: direction</li>
+ * <li>Bit 1: northern or southern heads</li>
+ * <li>Bit 2: Set if the bridge head is sloped</li>
+ * <li>Bit 3 and more: Railtype Specific subset</li>
+ * </ul>
+ * Please note that in this code, "roads" are treated as railtype 1, whilst the real railtypes are 0, 2 and 3
+ */
+static void DrawTile_Bridge(TileInfo *ti)
+{
+ uint32 image;
+
+ int base_offset;
+ bool ice = HasBridgeSnowOrDesert(ti->tile);
+
+ if (GetBridgeTransportType(ti->tile) == TRANSPORT_RAIL) {
+ if (GetTrackBits(ti->tile) != TRACK_BIT_X && GetTrackBits(ti->tile) != TRACK_BIT_Y) {
+ DrawTile_Track(ti);
+ return;
+ }
+ base_offset = GetRailTypeInfo(GetRailType(ti->tile))->bridge_offset;
+ assert(base_offset != 8); /* This one is used for roads */
+ } else {
+ base_offset = 8;
+ }
+
+ /* as the lower 3 bits are used for other stuff, make sure they are clear */
+ assert( (base_offset & 0x07) == 0x00);
+
+ if (!HASBIT(BRIDGE_NO_FOUNDATION, ti->tileh)) {
+ int f = GetBridgeFoundation(ti->tileh, DiagDirToAxis(GetBridgeRampDirection(ti->tile)));
+ if (f != 0) DrawFoundation(ti, f);
+ }
+
+ // HACK Wizardry to convert the bridge ramp direction into a sprite offset
+ base_offset += (6 - GetBridgeRampDirection(ti->tile)) % 4;
+
+ if (ti->tileh == SLOPE_FLAT) base_offset += 4; // sloped bridge head
+
+ /* Table number 6 always refers to the bridge heads for any bridge type */
+ image = GetBridgeSpriteTable(GetBridgeType(ti->tile), 6)[base_offset];
+
+ if (!ice) {
+ DrawClearLandTile(ti, 3);
+ } else {
+ DrawGroundSprite(SPR_FLAT_SNOWY_TILE + _tileh_to_sprite[ti->tileh]);
+ }
+
+ if (GetRailType(ti->tile) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
+
+ // draw ramp
+ if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
+ /* HACK set the height of the BB of a sloped ramp to 1 so a vehicle on
+ * it doesn't disappear behind it
+ */
+ AddSortableSpriteToDraw(
+ image, ti->x, ti->y, 16, 16, ti->tileh == SLOPE_FLAT ? 1 : 8, ti->z
+ );
+
+ if (IsTileType(ti->tile, MP_RAILWAY_BRIDGE) && HasSignals(ti->tile)) DrawSignals(ti->tile, GetTrackBits(ti->tile));
+
+ DrawBridgeMiddle(ti);
+}
+
+
+/** Compute bridge piece. Computes the bridge piece to display depending on the position inside the bridge.
+ * bridges pieces sequence (middle parts)
+ * bridge len 1: 0
+ * bridge len 2: 0 1
+ * bridge len 3: 0 4 1
+ * bridge len 4: 0 2 3 1
+ * bridge len 5: 0 2 5 3 1
+ * bridge len 6: 0 2 3 2 3 1
+ * bridge len 7: 0 2 3 4 2 3 1
+ * #0 - always as first, #1 - always as last (if len>1)
+ * #2,#3 are to pair in order
+ * for odd bridges: #5 is going in the bridge middle if on even position, #4 on odd (counting from 0)
+ * @param north Northernmost tile of bridge
+ * @param south Southernmost tile of bridge
+ * @return Index of bridge piece
+ */
+static uint CalcBridgePiece(uint north, uint south)
+{
+ if (north == 1) {
+ return 0;
+ } else if (south == 1) {
+ return 1;
+ } else if (north < south) {
+ return north & 1 ? 3 : 2;
+ } else if (north > south) {
+ return south & 1 ? 2 : 3;
+ } else {
+ return north & 1 ? 5 : 4;
+ }
+}
+
+
+void DrawBridgeMiddle(const TileInfo* ti)
+{
+ const PalSpriteID* b;
+ PalSpriteID image;
+ uint base_offset;
+ TileIndex rampnorth;
+ TileIndex rampsouth;
+ Axis axis;
+ uint piece;
+ uint type;
+ int x;
+ int y;
+ uint z;
+
+ if (!IsBridgeAbove(ti->tile)) return;
+
+ rampnorth = GetNorthernBridgeEnd(ti->tile);
+ rampsouth = GetSouthernBridgeEnd(ti->tile);
+
+ axis = GetBridgeAxis(ti->tile);
+ piece = CalcBridgePiece(
+ DistanceManhattan(ti->tile, rampnorth),
+ DistanceManhattan(ti->tile, rampsouth)
+ );
+ type = GetBridgeType(rampsouth);
+
+ if (GetBridgeTransportType(rampsouth) == TRANSPORT_RAIL) {
+ base_offset = GetRailTypeInfo(GetRailType(rampsouth))->bridge_offset;
+ } else {
+ base_offset = 8;
+ }
+
+ b = base_offset + GetBridgeSpriteTable(type, piece);
+ if (axis != AXIS_X) b += 4;
+
+ x = ti->x;
+ y = ti->y;
+ z = GetBridgeHeight(rampsouth) - 3;
+
+ image = b[0];
+ if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
+ if (axis == AXIS_X) {
+ AddSortableSpriteToDraw(image, x, y, 16, 11, 1, z);
+ } else {
+ AddSortableSpriteToDraw(image, x, y, 11, 16, 1, z);
+ }
+
+ image = b[1];
+ if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
+
+ // draw roof, the component of the bridge which is logically between the vehicle and the camera
+ if (axis == AXIS_X) {
+ y += 12;
+ if (image & SPRITE_MASK) AddSortableSpriteToDraw(image, x, y, 16, 1, 0x28, z);
+ } else {
+ x += 12;
+ if (image & SPRITE_MASK) AddSortableSpriteToDraw(image, x, y, 1, 16, 0x28, z);
+ }
+
+ if (GetRailType(rampsouth) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
+
+ if (ti->z + 5 == z) {
+ // draw poles below for small bridges
+ image = b[2];
+ if (image != 0) {
+ if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
+ DrawGroundSpriteAt(image, x, y, z);
+ }
+ } else if (_patches.bridge_pillars) {
+ // draw pillars below for high bridges
+ DrawBridgePillars(b[2], ti, axis, type, x, y, z);
+ }
+}
+
+
+uint SetSpeedLimitOnBridge(Vehicle *v)
+{
+ uint bridge_speed;
+ if (v->vehstatus & VS_HIDDEN) return v->max_speed; /* in tunnel */
+
+ bridge_speed = _bridge[GetBridgeType(v->tile)].speed;
+
+ if (v->type == VEH_Road) bridge_speed *= 2; /* XXX give vehicles proper speeds */
+
+ if (v->cur_speed > bridge_speed) v->cur_speed = bridge_speed;
+ return bridge_speed;
+}
+
+static bool IsCustomBridgeHead(TileIndex tile)
+{
+ assert(IsBridgeTile(tile));
+
+ if (IsTileType(tile, MP_RAILWAY_BRIDGE)) {
+ return !(GetTrackBits(tile) == TRACK_BIT_X || GetTrackBits(tile) == TRACK_BIT_Y);
+ }
+
+ return false; /* TODO - street bridges */
+}
+
+
+/** Gets the absolute z coordinate of a point inside a bridge tile
+ * When we're on the track (that means between position 5 and 10)
+ * on the coordinate perpendicular to the track it returns the base
+ * height of the ramp
+ * Outside this range (from 0 to 4 and from 11 to 15) it returns the
+ * "true" Z coordinate of the tile by taking the slope into account
+ * For custom bridge heads the entire bridge head is flat and has the
+ * same z coordinate
+ * @param tile The index of the tile we are talking about
+ * @param x Absolute or relative x coordinate
+ * @param y Absolute or relative y coordinate
+ * @return Absolute z coordinate
+ */
+static uint GetSlopeZ_Bridge(TileIndex tile, uint x, uint y)
+{
+ uint z, pos;
+ Slope tileh = GetTileSlope(tile, &z);
+ DiagDirection dir = GetBridgeRampDirection(tile);
+
+ x &= 0xF;
+ y &= 0xF;
+
+ pos = (DiagDirToAxis(dir) == AXIS_X ? y : x);
+
+ // On the bridge ramp or flat bridge head?
+ if ( (2 <= pos && pos <= 13) || IsCustomBridgeHead(tile)) {
+ uint delta;
+
+ if (IsSteepSlope(tileh)) return z + TILE_HEIGHT * 2;
+
+ if (HASBIT(BRIDGE_HORZ_RAMP, tileh)) return z + TILE_HEIGHT;
+
+ if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh)) z += TILE_HEIGHT;
+ switch (dir) {
+ default: NOT_REACHED();
+ case DIAGDIR_NE: delta = (TILE_SIZE - 1 - x) / 2; break;
+ case DIAGDIR_SE: delta = y / 2; break;
+ case DIAGDIR_SW: delta = x / 2; break;
+ case DIAGDIR_NW: delta = (TILE_SIZE - 1 - y) / 2; break;
+ }
+ return z + 1 + delta;
+ } else {
+ uint f = GetBridgeFoundation(tileh, DiagDirToAxis(dir));
+
+ if (f != 0) {
+ if (IsSteepSlope(tileh)) {
+ z += TILE_HEIGHT;
+ } else if (f < 15) {
+ return z + TILE_HEIGHT;
+ }
+ tileh = _inclined_tileh[f - 15];
+ }
+ }
+ return z + GetPartialZ(x, y, tileh);
+}
+
+static Slope GetSlopeTileh_Bridge(TileIndex tile, Slope tileh)
+{
+ if (HASBIT(BRIDGE_NO_FOUNDATION, tileh)) {
+ return tileh;
+ } else {
+ uint f = GetBridgeFoundation(tileh, DiagDirToAxis(GetBridgeRampDirection(tile)));
+
+ if (f == 0) return tileh;
+ if (f < 15) return SLOPE_FLAT;
+ return _inclined_tileh[f - 15];
+ }
+}
+
+static void GetAcceptedCargo_Bridge(TileIndex tile, AcceptedCargo ac)
+{
+ /* not used */
+}
+
+static const StringID _bridge_tile_str[(MAX_BRIDGES + 3) + (MAX_BRIDGES + 3)] = {
+ STR_501F_WOODEN_RAIL_BRIDGE,
+ STR_5020_CONCRETE_RAIL_BRIDGE,
+ STR_501C_STEEL_GIRDER_RAIL_BRIDGE,
+ STR_501E_REINFORCED_CONCRETE_SUSPENSION,
+ STR_501B_STEEL_SUSPENSION_RAIL_BRIDGE,
+ STR_501B_STEEL_SUSPENSION_RAIL_BRIDGE,
+ STR_501D_STEEL_CANTILEVER_RAIL_BRIDGE,
+ STR_501D_STEEL_CANTILEVER_RAIL_BRIDGE,
+ STR_501D_STEEL_CANTILEVER_RAIL_BRIDGE,
+ STR_501C_STEEL_GIRDER_RAIL_BRIDGE,
+ STR_5027_TUBULAR_RAIL_BRIDGE,
+ STR_5027_TUBULAR_RAIL_BRIDGE,
+ STR_5027_TUBULAR_RAIL_BRIDGE,
+ 0, 0, 0,
+
+ STR_5025_WOODEN_ROAD_BRIDGE,
+ STR_5026_CONCRETE_ROAD_BRIDGE,
+ STR_5022_STEEL_GIRDER_ROAD_BRIDGE,
+ STR_5024_REINFORCED_CONCRETE_SUSPENSION,
+ STR_5021_STEEL_SUSPENSION_ROAD_BRIDGE,
+ STR_5021_STEEL_SUSPENSION_ROAD_BRIDGE,
+ STR_5023_STEEL_CANTILEVER_ROAD_BRIDGE,
+ STR_5023_STEEL_CANTILEVER_ROAD_BRIDGE,
+ STR_5023_STEEL_CANTILEVER_ROAD_BRIDGE,
+ STR_5022_STEEL_GIRDER_ROAD_BRIDGE,
+ STR_5028_TUBULAR_ROAD_BRIDGE,
+ STR_5028_TUBULAR_ROAD_BRIDGE,
+ STR_5028_TUBULAR_ROAD_BRIDGE,
+ 0, 0, 0,
+};
+
+static void GetTileDesc_Bridge(TileIndex tile, TileDesc *td)
+{
+ td->str = _bridge_tile_str[GetBridgeTransportType(tile) << 4 | GetBridgeType(tile)];
+ td->owner = GetTileOwner(tile);
+}
+
+
+static void AnimateTile_Bridge(TileIndex tile)
+{
+ /* not used */
+}
+
+
+static void TileLoop_Bridge(TileIndex tile)
+{
+ bool snow_or_desert = HasBridgeSnowOrDesert(tile);
+ switch (_opt.landscape) {
+ case LT_HILLY:
+ if (snow_or_desert != (GetTileZ(tile) > _opt.snow_line)) {
+ SetBridgeSnowOrDesert(tile, !snow_or_desert);
+ MarkTileDirtyByTile(tile);
+ }
+ break;
+
+ case LT_DESERT:
+ if (GetTropicZone(tile) == TROPICZONE_DESERT && !snow_or_desert) {
+ SetBridgeSnowOrDesert(tile, true);
+ MarkTileDirtyByTile(tile);
+ }
+ break;
+ }
+}
+
+static void ClickTile_Bridge(TileIndex tile)
+{
+ /* not used */
+}
+
+
+static uint32 GetTileTrackStatus_Bridge(TileIndex tile, TransportType mode)
+{
+ if (GetBridgeTransportType(tile) != mode) return 0;
+
+ if (IsTileType(tile, MP_RAILWAY_BRIDGE)) return GetTileTrackStatus_Track(tile, mode);
+ return AxisToTrackBits(DiagDirToAxis(GetBridgeRampDirection(tile))) * 0x101;
+}
+
+
+static void ChangeTileOwner_Bridge(TileIndex tile, PlayerID old_player, PlayerID new_player)
+{
+ if (!IsTileOwner(tile, old_player)) return;
+
+ if (new_player != PLAYER_SPECTATOR) {
+ SetTileOwner(tile, new_player);
+ } else {
+ DoCommand(tile, 0, 0, DC_EXEC, CMD_LANDSCAPE_CLEAR);
+ }
+}
+
+
+static uint32 VehicleEnter_Street_Bridge(Vehicle *v, TileIndex tile, int x, int y)
+{
+ int z = GetSlopeZ(x, y) - v->z_pos;
+
+ DiagDirection dir;
+
+ if (myabs(z) > 2) return 8;
+
+ if (v->type == VEH_Road) {
+ /* modify speed of vehicle */
+ uint16 spd = _bridge[GetBridgeType(tile)].speed * 2;
+ if (v->cur_speed > spd) v->cur_speed = spd;
+ }
+
+ dir = GetBridgeRampDirection(tile);
+ if (DirToDiagDir(v->direction) == dir) {
+ switch (dir) {
+ default: NOT_REACHED();
+ case DIAGDIR_NE: if ((x & 0xF) != 0) return 0; break;
+ case DIAGDIR_SE: if ((y & 0xF) != TILE_SIZE - 1) return 0; break;
+ case DIAGDIR_SW: if ((x & 0xF) != TILE_SIZE - 1) return 0; break;
+ case DIAGDIR_NW: if ((y & 0xF) != 0) return 0; break;
+ }
+ v->u.road.state = 0xFF;
+ return 4;
+ } else if (DirToDiagDir(v->direction) == ReverseDiagDir(dir)) {
+ v->tile = tile;
+ if (v->u.road.state == 0xFF) {
+ static const byte road_exit_bridge_state[4] = {8, 9, 0, 1};
+ v->u.road.state = road_exit_bridge_state[dir];
+ v->u.road.frame = 0;
+ return 4;
+ }
+ return 0;
+ }
+ return 0;
+}
+
+/**
+ * @retval 0 The vehicle can proceed
+ * @retval 4 The vehicle changed onto of off the bridge (depending on the
+ * status before, check with v->u.rail.track == 0x40)
+ * @retval 8 The vehicle cannot enter the tile
+ */
+static uint32 VehicleEnter_Railway_Bridge(Vehicle *v, TileIndex tile, int x, int y)
+{
+ int z = GetSlopeZ(x, y) - v->z_pos;
+
+ DiagDirection dir;
+
+ if (IsCustomBridgeHead(tile)) {
+ uint h;
+ GetTileSlope(tile, &h);
+
+ z = h + TILE_HEIGHT - v->z_pos;
+ }
+
+ if (myabs(z) > 2) return 8;
+
+ if (IsFrontEngine(v)) {
+ /* modify speed of vehicle */
+ uint16 spd = _bridge[GetBridgeType(tile)].speed;
+ if (v->cur_speed > spd) v->cur_speed = spd;
+ }
+
+ dir = GetBridgeRampDirection(tile);
+
+ if (v->direction == DiagDirToDir(ReverseDiagDir(dir))) {
+ /* We are entering the bridge head from the bridge itself */
+ if (v->u.rail.track == 0x40) {
+ /* Get the vehicle out of the wormhole, the track will be chosen later
+ by the pathfinder */
+ v->tile = tile;
+ v->u.rail.track = TrackToTrackBits(TrackdirToTrack(DiagdirToDiagTrackdir(dir)));
+ return 4;
+ }
+ return 0;
+
+ } else {
+ TileIndex other_bridge_end_tile;
+ uint32 bridge_length;
+ /* We are on the bridge head itself, possibly entering the bridge */
+ /* Vehicle will enter the bridge wormhole when it reaches the tile edge in the
+ * direction of the bridge. */
+ TileIndexDiffC diff = TileIndexDiffCByDiagDir(dir);
+ /* If vehicle didn't reach the edge we can return and try it next time */
+ if (((diff.x != 0 ? x : y) & 0x0F) != (diff.x + diff.y > 0 ? TILE_SIZE - 1 : 0)) return 0;
+ /* We will enter the bridge wormhole. */
+
+ other_bridge_end_tile = GetOtherBridgeEnd(tile);
+ bridge_length = GetBridgeLength(tile, other_bridge_end_tile);
+ if (bridge_length > 0) {
+ /* Non-zero bridge length. Adjust the other coordinate to the middle of tile
+ * to allow train controller to select proper vehicle image */
+ if (diff.x != 0) v->y_pos = y; else v->x_pos = x;
+ v->direction = DiagDirToDir(dir);
+ /* We're about to enter the bridge body, clear all up/down flags just in case */
+ v->u.rail.track = 0x40;
+ v->direction = DiagDirToDir(dir);
+ CLRBIT(v->u.rail.flags, VRF_GOINGUP);
+ CLRBIT(v->u.rail.flags, VRF_GOINGDOWN);
+ return 4;
+ } else {
+ /* Zero bridge length. Pretend that nothing extra happened. Custom bridge heads should act as normal tracks. */
+ ;
+ }
+ }
+ return 0;
+}
+
+static uint32 VehicleEnter_Bridge(Vehicle *v, TileIndex tile, int x, int y)
+{
+ if (v->type == VEH_Train) return VehicleEnter_Railway_Bridge(v, tile, x, y);
+
+ if (v->type == VEH_Road) return VehicleEnter_Street_Bridge(v, tile, x, y);
+
+ NOT_REACHED();
+}
+
+const TileTypeProcs _tile_type_bridge_procs = {
+ DrawTile_Bridge, /* draw_tile_proc */
+ GetSlopeZ_Bridge, /* get_slope_z_proc */
+ ClearTile_Bridge, /* clear_tile_proc */
+ GetAcceptedCargo_Bridge, /* get_accepted_cargo_proc */
+ GetTileDesc_Bridge, /* get_tile_desc_proc */
+ GetTileTrackStatus_Bridge, /* get_tile_track_status_proc */
+ ClickTile_Bridge, /* click_tile_proc */
+ AnimateTile_Bridge, /* animate_tile_proc */
+ TileLoop_Bridge, /* tile_loop_clear */
+ ChangeTileOwner_Bridge, /* change_tile_owner_clear */
+ NULL, /* get_produced_cargo_proc */
+ VehicleEnter_Bridge, /* vehicle_enter_tile_proc */
+ GetSlopeTileh_Bridge, /* get_slope_tileh_proc */
+};