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https://github.com/OpenTTD/OpenTTD.git
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913 lines
25 KiB
C
913 lines
25 KiB
C
#include "stdafx.h"
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#include "openttd.h"
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#include "map.h"
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#include "tile.h"
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#include "pathfind.h"
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#include "rail.h"
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#include "debug.h"
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#include "variables.h"
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// remember which tiles we have already visited so we don't visit them again.
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static bool TPFSetTileBit(TrackPathFinder *tpf, TileIndex tile, int dir)
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{
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uint hash, val, offs;
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TrackPathFinderLink *link, *new_link;
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uint bits = 1 << dir;
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if (tpf->disable_tile_hash)
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return true;
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hash = PATHFIND_HASH_TILE(tile);
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val = tpf->hash_head[hash];
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if (val == 0) {
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/* unused hash entry, set the appropriate bit in it and return true
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* to indicate that a bit was set. */
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tpf->hash_head[hash] = bits;
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tpf->hash_tile[hash] = tile;
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return true;
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} else if (!(val & 0x8000)) {
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/* single tile */
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if (tile == tpf->hash_tile[hash]) {
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/* found another bit for the same tile,
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* check if this bit is already set, if so, return false */
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if (val & bits)
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return false;
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/* otherwise set the bit and return true to indicate that the bit
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* was set */
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tpf->hash_head[hash] = val | bits;
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return true;
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} else {
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/* two tiles with the same hash, need to make a link */
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/* allocate a link. if out of links, handle this by returning
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* that a tile was already visisted. */
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if (tpf->num_links_left == 0) {
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return false;
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}
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tpf->num_links_left--;
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link = tpf->new_link++;
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/* move the data that was previously in the hash_??? variables
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* to the link struct, and let the hash variables point to the link */
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link->tile = tpf->hash_tile[hash];
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tpf->hash_tile[hash] = PATHFIND_GET_LINK_OFFS(tpf, link);
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link->flags = tpf->hash_head[hash];
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tpf->hash_head[hash] = 0xFFFF; /* multi link */
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link->next = 0xFFFF;
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}
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} else {
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/* a linked list of many tiles,
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* find the one corresponding to the tile, if it exists.
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* otherwise make a new link */
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offs = tpf->hash_tile[hash];
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do {
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link = PATHFIND_GET_LINK_PTR(tpf, offs);
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if (tile == link->tile) {
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/* found the tile in the link list,
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* check if the bit was alrady set, if so return false to indicate that the
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* bit was already set */
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if (link->flags & bits)
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return false;
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link->flags |= bits;
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return true;
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}
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} while ((offs=link->next) != 0xFFFF);
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}
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/* get here if we need to add a new link to link,
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* first, allocate a new link, in the same way as before */
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if (tpf->num_links_left == 0) {
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return false;
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}
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tpf->num_links_left--;
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new_link = tpf->new_link++;
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/* then fill the link with the new info, and establish a ptr from the old
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* link to the new one */
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new_link->tile = tile;
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new_link->flags = bits;
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new_link->next = 0xFFFF;
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link->next = PATHFIND_GET_LINK_OFFS(tpf, new_link);
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return true;
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}
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static const byte _bits_mask[4] = {
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0x19,
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0x16,
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0x25,
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0x2A,
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};
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static const byte _tpf_new_direction[14] = {
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0,1,0,1,2,1, 0,0,
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2,3,3,2,3,0,
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};
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static const byte _tpf_prev_direction[14] = {
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0,1,1,0,1,2, 0,0,
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2,3,2,3,0,3,
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};
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static const byte _otherdir_mask[4] = {
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0x10,
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0,
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0x5,
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0x2A,
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};
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static void TPFMode2(TrackPathFinder *tpf, TileIndex tile, int direction)
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{
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uint bits;
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int i;
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RememberData rd;
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int owner = -1;
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/* XXX: Mode 2 is currently only used for ships, why is this code here? */
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if (tpf->tracktype == TRANSPORT_RAIL) {
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if (IsTileType(tile, MP_RAILWAY) || IsTileType(tile, MP_STATION) || IsTileType(tile, MP_TUNNELBRIDGE)) {
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owner = GetTileOwner(tile);
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/* Check if we are on the middle of a bridge (has no owner) */
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if (IsTileType(tile, MP_TUNNELBRIDGE) && (_m[tile].m5 & 0xC0) == 0xC0)
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owner = -1;
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}
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}
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// This addition will sometimes overflow by a single tile.
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// The use of TILE_MASK here makes sure that we still point at a valid
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// tile, and then this tile will be in the sentinel row/col, so GetTileTrackStatus will fail.
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tile = TILE_MASK(tile + TileOffsByDir(direction));
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/* Check in case of rail if the owner is the same */
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if (tpf->tracktype == TRANSPORT_RAIL) {
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if (IsTileType(tile, MP_RAILWAY) || IsTileType(tile, MP_STATION) || IsTileType(tile, MP_TUNNELBRIDGE))
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/* Check if we are on the middle of a bridge (has no owner) */
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if (!IsTileType(tile, MP_TUNNELBRIDGE) || (_m[tile].m5 & 0xC0) != 0xC0)
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if (owner != -1 && !IsTileOwner(tile, owner))
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return;
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}
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if (++tpf->rd.cur_length > 50)
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return;
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bits = GetTileTrackStatus(tile, tpf->tracktype);
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bits = (byte)((bits | (bits >> 8)) & _bits_mask[direction]);
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if (bits == 0)
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return;
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assert(TileX(tile) != MapMaxX() && TileY(tile) != MapMaxY());
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if ( (bits & (bits - 1)) == 0 ) {
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/* only one direction */
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i = 0;
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while (!(bits&1))
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i++, bits>>=1;
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rd = tpf->rd;
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goto continue_here;
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}
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/* several directions */
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i=0;
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do {
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if (!(bits & 1)) continue;
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rd = tpf->rd;
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// Change direction 4 times only
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if ((byte)i != tpf->rd.pft_var6) {
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if(++tpf->rd.depth > 4) {
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tpf->rd = rd;
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return;
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}
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tpf->rd.pft_var6 = (byte)i;
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}
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continue_here:;
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tpf->the_dir = HASBIT(_otherdir_mask[direction],i) ? (i+8) : i;
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if (!tpf->enum_proc(tile, tpf->userdata, tpf->the_dir, tpf->rd.cur_length, NULL)) {
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TPFMode2(tpf, tile, _tpf_new_direction[tpf->the_dir]);
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}
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tpf->rd = rd;
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} while (++i, bits>>=1);
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}
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static const int8 _get_tunlen_inc[5] = { -16, 0, 16, 0, -16 };
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/* Returns the end tile and the length of a tunnel. The length does not
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* include the starting tile (entry), it does include the end tile (exit).
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*/
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FindLengthOfTunnelResult FindLengthOfTunnel(TileIndex tile, int direction)
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{
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FindLengthOfTunnelResult flotr;
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int x,y;
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byte z;
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flotr.length = 0;
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x = TileX(tile) * 16;
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y = TileY(tile) * 16;
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z = GetSlopeZ(x+8, y+8);
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for(;;) {
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flotr.length++;
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x += _get_tunlen_inc[direction];
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y += _get_tunlen_inc[direction+1];
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tile = TileVirtXY(x, y);
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if (IsTileType(tile, MP_TUNNELBRIDGE) &&
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(_m[tile].m5 & 0xF0) == 0 && // tunnel entrance/exit
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//((_m[tile].m5>>2)&3) == type && // rail/road-tunnel <-- This is not necesary to check, right?
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((_m[tile].m5 & 3)^2) == direction && // entrance towards: 0 = NE, 1 = SE, 2 = SW, 3 = NW
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GetSlopeZ(x+8, y+8) == z)
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break;
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}
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flotr.tile = tile;
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return flotr;
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}
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static const uint16 _tpfmode1_and[4] = { 0x1009, 0x16, 0x520, 0x2A00 };
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static uint SkipToEndOfTunnel(TrackPathFinder *tpf, TileIndex tile, int direction)
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{
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FindLengthOfTunnelResult flotr;
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TPFSetTileBit(tpf, tile, 14);
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flotr = FindLengthOfTunnel(tile, direction);
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tpf->rd.cur_length += flotr.length;
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TPFSetTileBit(tpf, flotr.tile, 14);
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return flotr.tile;
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}
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const byte _ffb_64[128] = {
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0,0,1,0,2,0,1,0,
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3,0,1,0,2,0,1,0,
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4,0,1,0,2,0,1,0,
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3,0,1,0,2,0,1,0,
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5,0,1,0,2,0,1,0,
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3,0,1,0,2,0,1,0,
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4,0,1,0,2,0,1,0,
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3,0,1,0,2,0,1,0,
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0,0,0,2,0,4,4,6,
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0,8,8,10,8,12,12,14,
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0,16,16,18,16,20,20,22,
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16,24,24,26,24,28,28,30,
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0,32,32,34,32,36,36,38,
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32,40,40,42,40,44,44,46,
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32,48,48,50,48,52,52,54,
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48,56,56,58,56,60,60,62,
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};
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static void TPFMode1(TrackPathFinder *tpf, TileIndex tile, int direction)
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{
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uint bits;
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int i;
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RememberData rd;
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TileIndex tile_org = tile;
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if (IsTileType(tile, MP_TUNNELBRIDGE) && (_m[tile].m5 & 0xF0) == 0) {
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if ((_m[tile].m5 & 3) != direction || ((_m[tile].m5>>2)&3) != tpf->tracktype)
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return;
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tile = SkipToEndOfTunnel(tpf, tile, direction);
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}
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tile += TileOffsByDir(direction);
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/* Check in case of rail if the owner is the same */
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if (tpf->tracktype == TRANSPORT_RAIL) {
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if (IsTileType(tile_org, MP_RAILWAY) || IsTileType(tile_org, MP_STATION) || IsTileType(tile_org, MP_TUNNELBRIDGE))
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if (IsTileType(tile, MP_RAILWAY) || IsTileType(tile, MP_STATION) || IsTileType(tile, MP_TUNNELBRIDGE))
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/* Check if we are on a bridge (middle parts don't have an owner */
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if (!IsTileType(tile, MP_TUNNELBRIDGE) || (_m[tile].m5 & 0xC0) != 0xC0)
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if (!IsTileType(tile_org, MP_TUNNELBRIDGE) || (_m[tile_org].m5 & 0xC0) != 0xC0)
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if (GetTileOwner(tile_org) != GetTileOwner(tile))
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return;
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}
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tpf->rd.cur_length++;
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bits = GetTileTrackStatus(tile, tpf->tracktype);
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if ((byte)bits != tpf->var2) {
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bits &= _tpfmode1_and[direction];
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bits = bits | (bits>>8);
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}
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bits &= 0xBF;
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if (bits != 0) {
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if (!tpf->disable_tile_hash || (tpf->rd.cur_length <= 64 && (KILL_FIRST_BIT(bits) == 0 || ++tpf->rd.depth <= 7))) {
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do {
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i = FIND_FIRST_BIT(bits);
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bits = KILL_FIRST_BIT(bits);
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tpf->the_dir = (_otherdir_mask[direction] & (byte)(1 << i)) ? (i+8) : i;
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rd = tpf->rd;
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if (TPFSetTileBit(tpf, tile, tpf->the_dir) &&
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!tpf->enum_proc(tile, tpf->userdata, tpf->the_dir, tpf->rd.cur_length, &tpf->rd.pft_var6) ) {
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TPFMode1(tpf, tile, _tpf_new_direction[tpf->the_dir]);
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}
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tpf->rd = rd;
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} while (bits != 0);
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}
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}
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/* the next is only used when signals are checked.
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* seems to go in 2 directions simultaneously */
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/* if i can get rid of this, tail end recursion can be used to minimize
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* stack space dramatically. */
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/* If we are doing signal setting, we must reverse at evere tile, so we
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* iterate all the tracks in a signal block, even when a normal train would
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* not reach it (for example, when two lines merge */
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if (tpf->hasbit_13)
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return;
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tile = tile_org;
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direction ^= 2;
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bits = GetTileTrackStatus(tile, tpf->tracktype);
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bits |= (bits >> 8);
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if ( (byte)bits != tpf->var2) {
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bits &= _bits_mask[direction];
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}
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bits &= 0xBF;
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if (bits == 0)
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return;
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do {
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i = FIND_FIRST_BIT(bits);
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bits = KILL_FIRST_BIT(bits);
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tpf->the_dir = (_otherdir_mask[direction] & (byte)(1 << i)) ? (i+8) : i;
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rd = tpf->rd;
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if (TPFSetTileBit(tpf, tile, tpf->the_dir) &&
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!tpf->enum_proc(tile, tpf->userdata, tpf->the_dir, tpf->rd.cur_length, &tpf->rd.pft_var6) ) {
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TPFMode1(tpf, tile, _tpf_new_direction[tpf->the_dir]);
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}
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tpf->rd = rd;
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} while (bits != 0);
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}
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void FollowTrack(TileIndex tile, uint16 flags, byte direction, TPFEnumProc *enum_proc, TPFAfterProc *after_proc, void *data)
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{
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TrackPathFinder tpf;
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assert(direction < 4);
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/* initialize path finder variables */
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tpf.userdata = data;
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tpf.enum_proc = enum_proc;
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tpf.new_link = tpf.links;
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tpf.num_links_left = lengthof(tpf.links);
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tpf.rd.cur_length = 0;
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tpf.rd.depth = 0;
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tpf.rd.pft_var6 = 0;
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tpf.var2 = HASBIT(flags, 15) ? 0x43 : 0xFF; /* 0x8000 */
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tpf.disable_tile_hash = HASBIT(flags, 12) != 0; /* 0x1000 */
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tpf.hasbit_13 = HASBIT(flags, 13) != 0; /* 0x2000 */
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tpf.tracktype = (byte)flags;
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if (HASBIT(flags, 11)) {
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tpf.rd.pft_var6 = 0xFF;
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tpf.enum_proc(tile, data, 0, 0, 0);
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TPFMode2(&tpf, tile, direction);
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} else {
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/* clear the hash_heads */
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memset(tpf.hash_head, 0, sizeof(tpf.hash_head));
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TPFMode1(&tpf, tile, direction);
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}
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if (after_proc != NULL)
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after_proc(&tpf);
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}
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typedef struct {
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TileIndex tile;
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uint16 cur_length; // This is the current length to this tile.
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uint16 priority; // This is the current length + estimated length to the goal.
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byte track;
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byte depth;
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byte state;
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byte first_track;
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} StackedItem;
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static const byte _new_track[6][4] = {
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{0,0xff,8,0xff,},
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{0xff,1,0xff,9,},
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{0xff,2,10,0xff,},
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{3,0xff,0xff,11,},
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{12,4,0xff,0xff,},
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{0xff,0xff,5,13,},
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};
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typedef struct HashLink {
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TileIndex tile;
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uint16 typelength;
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uint16 next;
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} HashLink;
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typedef struct {
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NTPEnumProc *enum_proc;
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void *userdata;
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TileIndex dest;
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byte tracktype;
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uint maxlength;
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HashLink *new_link;
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uint num_links_left;
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uint nstack;
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StackedItem stack[256]; // priority queue of stacked items
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uint16 hash_head[0x400]; // hash heads. 0 means unused. 0xFFFC = length, 0x3 = dir
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TileIndex hash_tile[0x400]; // tiles. or links.
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HashLink links[0x400]; // hash links
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} NewTrackPathFinder;
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#define NTP_GET_LINK_OFFS(tpf, link) ((byte*)(link) - (byte*)tpf->links)
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#define NTP_GET_LINK_PTR(tpf, link_offs) (HashLink*)((byte*)tpf->links + (link_offs))
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#define ARR(i) tpf->stack[(i)-1]
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// called after a new element was added in the queue at the last index.
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// move it down to the proper position
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static inline void HeapifyUp(NewTrackPathFinder *tpf)
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{
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StackedItem si;
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int i = ++tpf->nstack;
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while (i != 1 && ARR(i).priority < ARR(i>>1).priority) {
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// the child element is larger than the parent item.
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// swap the child item and the parent item.
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si = ARR(i); ARR(i) = ARR(i>>1); ARR(i>>1) = si;
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i>>=1;
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}
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}
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// called after the element 0 was eaten. fill it with a new element
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static inline void HeapifyDown(NewTrackPathFinder *tpf)
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{
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StackedItem si;
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int i = 1, j;
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int n;
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assert(tpf->nstack > 0);
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n = --tpf->nstack;
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if (n == 0) return; // heap is empty so nothing to do?
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// copy the last item to index 0. we use it as base for heapify.
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ARR(1) = ARR(n+1);
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while ((j=i*2) <= n) {
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// figure out which is smaller of the children.
|
|
if (j != n && ARR(j).priority > ARR(j+1).priority)
|
|
j++; // right item is smaller
|
|
|
|
assert(i <= n && j <= n);
|
|
if (ARR(i).priority <= ARR(j).priority)
|
|
break; // base elem smaller than smallest, done!
|
|
|
|
// swap parent with the child
|
|
si = ARR(i); ARR(i) = ARR(j); ARR(j) = si;
|
|
i = j;
|
|
}
|
|
}
|
|
|
|
// mark a tile as visited and store the length of the path.
|
|
// if we already had a better path to this tile, return false.
|
|
// otherwise return true.
|
|
static bool NtpVisit(NewTrackPathFinder *tpf, TileIndex tile, uint dir, uint length)
|
|
{
|
|
uint hash,head;
|
|
HashLink *link, *new_link;
|
|
|
|
assert(length < 16384-1);
|
|
|
|
hash = PATHFIND_HASH_TILE(tile);
|
|
|
|
// never visited before?
|
|
if ((head=tpf->hash_head[hash]) == 0) {
|
|
tpf->hash_tile[hash] = tile;
|
|
tpf->hash_head[hash] = dir | (length << 2);
|
|
return true;
|
|
}
|
|
|
|
if (head != 0xffff) {
|
|
if (tile == tpf->hash_tile[hash] && (head & 0x3) == dir) {
|
|
|
|
// longer length
|
|
if (length >= (head >> 2)) return false;
|
|
|
|
tpf->hash_head[hash] = dir | (length << 2);
|
|
return true;
|
|
}
|
|
// two tiles with the same hash, need to make a link
|
|
// allocate a link. if out of links, handle this by returning
|
|
// that a tile was already visisted.
|
|
if (tpf->num_links_left == 0) {
|
|
DEBUG(ntp, 1) ("[NTP] no links left");
|
|
return false;
|
|
}
|
|
|
|
tpf->num_links_left--;
|
|
link = tpf->new_link++;
|
|
|
|
/* move the data that was previously in the hash_??? variables
|
|
* to the link struct, and let the hash variables point to the link */
|
|
link->tile = tpf->hash_tile[hash];
|
|
tpf->hash_tile[hash] = NTP_GET_LINK_OFFS(tpf, link);
|
|
|
|
link->typelength = tpf->hash_head[hash];
|
|
tpf->hash_head[hash] = 0xFFFF; /* multi link */
|
|
link->next = 0xFFFF;
|
|
} else {
|
|
// a linked list of many tiles,
|
|
// find the one corresponding to the tile, if it exists.
|
|
// otherwise make a new link
|
|
|
|
uint offs = tpf->hash_tile[hash];
|
|
do {
|
|
link = NTP_GET_LINK_PTR(tpf, offs);
|
|
if (tile == link->tile && (uint)(link->typelength & 0x3) == dir) {
|
|
if (length >= (uint)(link->typelength >> 2)) return false;
|
|
link->typelength = dir | (length << 2);
|
|
return true;
|
|
}
|
|
} while ((offs=link->next) != 0xFFFF);
|
|
}
|
|
|
|
/* get here if we need to add a new link to link,
|
|
* first, allocate a new link, in the same way as before */
|
|
if (tpf->num_links_left == 0) {
|
|
DEBUG(ntp, 1) ("[NTP] no links left");
|
|
return false;
|
|
}
|
|
tpf->num_links_left--;
|
|
new_link = tpf->new_link++;
|
|
|
|
/* then fill the link with the new info, and establish a ptr from the old
|
|
* link to the new one */
|
|
new_link->tile = tile;
|
|
new_link->typelength = dir | (length << 2);
|
|
new_link->next = 0xFFFF;
|
|
|
|
link->next = NTP_GET_LINK_OFFS(tpf, new_link);
|
|
return true;
|
|
}
|
|
|
|
static bool NtpCheck(NewTrackPathFinder *tpf, TileIndex tile, uint dir, uint length)
|
|
{
|
|
uint hash,head,offs;
|
|
HashLink *link;
|
|
|
|
hash = PATHFIND_HASH_TILE(tile);
|
|
head=tpf->hash_head[hash];
|
|
assert(head);
|
|
|
|
if (head != 0xffff) {
|
|
assert( tpf->hash_tile[hash] == tile && (head & 3) == dir);
|
|
assert( (head >> 2) <= length);
|
|
return length == (head >> 2);
|
|
}
|
|
|
|
// else it's a linked list of many tiles
|
|
offs = tpf->hash_tile[hash];
|
|
for(;;) {
|
|
link = NTP_GET_LINK_PTR(tpf, offs);
|
|
if (tile == link->tile && (uint)(link->typelength & 0x3) == dir) {
|
|
assert( (uint)(link->typelength >> 2) <= length);
|
|
return length == (uint)(link->typelength >> 2);
|
|
}
|
|
offs = link->next;
|
|
assert(offs != 0xffff);
|
|
}
|
|
}
|
|
|
|
|
|
static const uint16 _is_upwards_slope[15] = {
|
|
0, // no tileh
|
|
(1 << TRACKDIR_DIAG1_SW) | (1 << TRACKDIR_DIAG2_NW), // 1
|
|
(1 << TRACKDIR_DIAG1_SW) | (1 << TRACKDIR_DIAG2_SE), // 2
|
|
(1 << TRACKDIR_DIAG1_SW), // 3
|
|
(1 << TRACKDIR_DIAG1_NE) | (1 << TRACKDIR_DIAG2_SE), // 4
|
|
0, // 5
|
|
(1 << TRACKDIR_DIAG2_SE), // 6
|
|
0, // 7
|
|
(1 << TRACKDIR_DIAG1_NE) | (1 << TRACKDIR_DIAG2_NW), // 8,
|
|
(1 << TRACKDIR_DIAG2_NW), // 9
|
|
0, //10
|
|
0, //11,
|
|
(1 << TRACKDIR_DIAG1_NE), //12
|
|
0, //13
|
|
0, //14
|
|
};
|
|
|
|
|
|
#define DIAG_FACTOR 3
|
|
#define STR_FACTOR 2
|
|
|
|
|
|
static uint DistanceMoo(TileIndex t0, TileIndex t1)
|
|
{
|
|
const uint dx = abs(TileX(t0) - TileX(t1));
|
|
const uint dy = abs(TileY(t0) - TileY(t1));
|
|
|
|
const uint straightTracks = 2 * min(dx, dy); /* The number of straight (not full length) tracks */
|
|
/* OPTIMISATION:
|
|
* Original: diagTracks = max(dx, dy) - min(dx,dy);
|
|
* Proof:
|
|
* (dx-dy) - straightTracks == (min + max) - straightTracks = min + // max - 2 * min = max - min */
|
|
const uint diagTracks = dx + dy - straightTracks; /* The number of diagonal (full tile length) tracks. */
|
|
|
|
return diagTracks*DIAG_FACTOR + straightTracks*STR_FACTOR;
|
|
}
|
|
|
|
// These has to be small cause the max length of a track
|
|
// is currently limited to 16384
|
|
|
|
static const byte _length_of_track[16] = {
|
|
DIAG_FACTOR,DIAG_FACTOR,STR_FACTOR,STR_FACTOR,STR_FACTOR,STR_FACTOR,0,0,
|
|
DIAG_FACTOR,DIAG_FACTOR,STR_FACTOR,STR_FACTOR,STR_FACTOR,STR_FACTOR,0,0
|
|
};
|
|
|
|
// new more optimized pathfinder for trains...
|
|
// Tile is the tile the train is at.
|
|
// direction is the tile the train is moving towards.
|
|
|
|
static void NTPEnum(NewTrackPathFinder *tpf, TileIndex tile, uint direction)
|
|
{
|
|
uint bits, tile_org, track;
|
|
StackedItem si;
|
|
FindLengthOfTunnelResult flotr;
|
|
int estimation;
|
|
|
|
|
|
|
|
// Need to have a special case for the start.
|
|
// We shouldn't call the callback for the current tile.
|
|
si.cur_length = 1; // Need to start at 1 cause 0 is a reserved value.
|
|
si.depth = 0;
|
|
si.state = 0;
|
|
si.first_track = 0xFF;
|
|
goto start_at;
|
|
|
|
for(;;) {
|
|
// Get the next item to search from from the priority queue
|
|
do {
|
|
if (tpf->nstack == 0)
|
|
return; // nothing left? then we're done!
|
|
si = tpf->stack[0];
|
|
tile = si.tile;
|
|
|
|
HeapifyDown(tpf);
|
|
// Make sure we havn't already visited this tile.
|
|
} while (!NtpCheck(tpf, tile, _tpf_prev_direction[si.track], si.cur_length));
|
|
|
|
// Add the length of this track.
|
|
si.cur_length += _length_of_track[si.track];
|
|
|
|
callback_and_continue:
|
|
if (tpf->enum_proc(tile, tpf->userdata, si.first_track, si.cur_length))
|
|
return;
|
|
|
|
assert(si.track <= 13);
|
|
direction = _tpf_new_direction[si.track];
|
|
|
|
start_at:
|
|
// If the tile is the entry tile of a tunnel, and we're not going out of the tunnel,
|
|
// need to find the exit of the tunnel.
|
|
if (IsTileType(tile, MP_TUNNELBRIDGE)) {
|
|
if ((_m[tile].m5 & 0xF0) == 0 &&
|
|
(uint)(_m[tile].m5 & 3) != (direction ^ 2)) {
|
|
/* This is a tunnel tile */
|
|
/* We are not just driving out of the tunnel */
|
|
if ( (uint)(_m[tile].m5 & 3) != direction || ((_m[tile].m5>>1)&6) != tpf->tracktype)
|
|
/* We are not driving into the tunnel, or it
|
|
* is an invalid tunnel */
|
|
continue;
|
|
flotr = FindLengthOfTunnel(tile, direction);
|
|
si.cur_length += flotr.length * DIAG_FACTOR;
|
|
tile = flotr.tile;
|
|
// tile now points to the exit tile of the tunnel
|
|
}
|
|
}
|
|
|
|
// This is a special loop used to go through
|
|
// a rail net and find the first intersection
|
|
tile_org = tile;
|
|
for(;;) {
|
|
assert(direction <= 3);
|
|
tile += TileOffsByDir(direction);
|
|
|
|
// too long search length? bail out.
|
|
if (si.cur_length >= tpf->maxlength) {
|
|
DEBUG(ntp,1) ("[NTP] cur_length too big");
|
|
bits = 0;
|
|
break;
|
|
}
|
|
|
|
// Not a regular rail tile?
|
|
// Then we can't use the code below, but revert to more general code.
|
|
if (!IsTileType(tile, MP_RAILWAY) || !IsPlainRailTile(tile)) {
|
|
// We found a tile which is not a normal railway tile.
|
|
// Determine which tracks that exist on this tile.
|
|
bits = GetTileTrackStatus(tile, TRANSPORT_RAIL) & _tpfmode1_and[direction];
|
|
bits = (bits | (bits >> 8)) & 0x3F;
|
|
|
|
// Check that the tile contains exactly one track
|
|
if (bits == 0 || KILL_FIRST_BIT(bits) != 0)
|
|
break;
|
|
|
|
///////////////////
|
|
// If we reach here, the tile has exactly one track.
|
|
// tile - index to a tile that is not rail tile, but still straight (with optional signals)
|
|
// bits - bitmask of which track that exist on the tile (exactly one bit is set)
|
|
// direction - which direction are we moving in?
|
|
///////////////////
|
|
si.track = _new_track[FIND_FIRST_BIT(bits)][direction];
|
|
si.cur_length += _length_of_track[si.track];
|
|
goto callback_and_continue;
|
|
}
|
|
|
|
// Regular rail tile, determine which tracks exist.
|
|
bits = _m[tile].m5 & _bits_mask[direction];
|
|
|
|
// The tile has no reachable tracks, or
|
|
// does the tile contain more than one track?
|
|
if (bits == 0 || KILL_FIRST_BIT(_m[tile].m5 & 0x3F) != 0)
|
|
break;
|
|
|
|
// If we reach here, the tile has exactly one track, and this
|
|
// track is reachable.
|
|
|
|
track = _new_track[FIND_FIRST_BIT(bits)][direction];
|
|
assert(track != 0xff);
|
|
|
|
si.cur_length += _length_of_track[track];
|
|
|
|
// Check if this rail is an upwards slope. If it is, then add a penalty.
|
|
// Small optimization here.. if (track&7)>1 then it can't be a slope so we avoid calling GetTileSlope
|
|
if ((track & 7) <= 1 && (_is_upwards_slope[GetTileSlope(tile, NULL)] & (1 << track)) ) {
|
|
// upwards slope. add some penalty.
|
|
si.cur_length += 4*DIAG_FACTOR;
|
|
}
|
|
|
|
// railway tile with signals..?
|
|
if (HasSignals(tile)) {
|
|
byte m3;
|
|
|
|
m3 = _m[tile].m3;
|
|
if (!(m3 & SignalAlongTrackdir(track))) {
|
|
// if one way signal not pointing towards us, stop going in this direction.
|
|
if (m3 & SignalAgainstTrackdir(track)) {
|
|
bits = 0;
|
|
break;
|
|
}
|
|
} else if (_m[tile].m2 & SignalAlongTrackdir(track)) {
|
|
// green signal in our direction. either one way or two way.
|
|
si.state |= 3;
|
|
} else {
|
|
// reached a red signal.
|
|
if (m3 & SignalAgainstTrackdir(track)) {
|
|
// two way red signal. unless we passed another green signal on the way,
|
|
// stop going in this direction.
|
|
// this is to prevent us from going into a full platform.
|
|
if (!(si.state&1)) {
|
|
bits = 0;
|
|
break;
|
|
}
|
|
}
|
|
if (!(si.state & 2)) {
|
|
// Is this the first signal we see? And it's red... add penalty
|
|
si.cur_length += 10*DIAG_FACTOR;
|
|
si.state += 2; // remember that we added penalty.
|
|
// Because we added a penalty, we can't just continue as usual.
|
|
// Need to get out and let A* do it's job with
|
|
// possibly finding an even shorter path.
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (tpf->enum_proc(tile, tpf->userdata, si.first_track, si.cur_length))
|
|
return;
|
|
}
|
|
|
|
// continue with the next track
|
|
direction = _tpf_new_direction[track];
|
|
|
|
// safety check if we're running around chasing our tail... (infinite loop)
|
|
if (tile == tile_org) {
|
|
bits = 0;
|
|
break;
|
|
}
|
|
}
|
|
|
|
// There are no tracks to choose between.
|
|
// Stop searching in this direction
|
|
if (bits == 0)
|
|
continue;
|
|
|
|
////////////////
|
|
// We got multiple tracks to choose between (intersection).
|
|
// Branch the search space into several branches.
|
|
////////////////
|
|
|
|
// Check if we've already visited this intersection.
|
|
// If we've already visited it with a better length, then
|
|
// there's no point in visiting it again.
|
|
if (!NtpVisit(tpf, tile, direction, si.cur_length))
|
|
continue;
|
|
|
|
// Push all possible alternatives that we can reach from here
|
|
// onto the priority heap.
|
|
// 'bits' contains the tracks that we can choose between.
|
|
|
|
// First compute the estimated distance to the target.
|
|
// This is used to implement A*
|
|
estimation = 0;
|
|
if (tpf->dest != 0)
|
|
estimation = DistanceMoo(tile, tpf->dest);
|
|
|
|
si.depth++;
|
|
si.tile = tile;
|
|
do {
|
|
si.track = _new_track[FIND_FIRST_BIT(bits)][direction];
|
|
si.priority = si.cur_length + estimation;
|
|
|
|
// out of stack items, bail out?
|
|
if (tpf->nstack >= lengthof(tpf->stack)) {
|
|
DEBUG(ntp, 1) ("[NTP] out of stack");
|
|
break;
|
|
}
|
|
|
|
tpf->stack[tpf->nstack] = si;
|
|
HeapifyUp(tpf);
|
|
} while ((bits = KILL_FIRST_BIT(bits)) != 0);
|
|
|
|
// If this is the first intersection, we need to fill the first_track member.
|
|
// so the code outside knows which path is better.
|
|
// also randomize the order in which we search through them.
|
|
if (si.depth == 1) {
|
|
assert(tpf->nstack == 1 || tpf->nstack == 2 || tpf->nstack == 3);
|
|
if (tpf->nstack != 1) {
|
|
uint32 r = Random();
|
|
if (r&1) swap_byte(&tpf->stack[0].track, &tpf->stack[1].track);
|
|
if (tpf->nstack != 2) {
|
|
byte t = tpf->stack[2].track;
|
|
if (r&2) swap_byte(&tpf->stack[0].track, &t);
|
|
if (r&4) swap_byte(&tpf->stack[1].track, &t);
|
|
tpf->stack[2].first_track = tpf->stack[2].track = t;
|
|
}
|
|
tpf->stack[0].first_track = tpf->stack[0].track;
|
|
tpf->stack[1].first_track = tpf->stack[1].track;
|
|
}
|
|
}
|
|
|
|
// Continue with the next from the queue...
|
|
}
|
|
}
|
|
|
|
|
|
// new pathfinder for trains. better and faster.
|
|
void NewTrainPathfind(TileIndex tile, TileIndex dest, byte direction, NTPEnumProc *enum_proc, void *data)
|
|
{
|
|
NewTrackPathFinder tpf;
|
|
|
|
tpf.dest = dest;
|
|
tpf.userdata = data;
|
|
tpf.enum_proc = enum_proc;
|
|
tpf.tracktype = 0;
|
|
tpf.maxlength = min(_patches.pf_maxlength * 3, 10000);
|
|
tpf.nstack = 0;
|
|
tpf.new_link = tpf.links;
|
|
tpf.num_links_left = lengthof(tpf.links);
|
|
memset(tpf.hash_head, 0, sizeof(tpf.hash_head));
|
|
|
|
NTPEnum(&tpf, tile, direction);
|
|
}
|
|
|