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#include "stdafx.h"
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#include "ttd.h"
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#include "pathfind.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, uint 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] = (TileIndex)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 ( (TileIndex)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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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 ( (TileIndex)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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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 = (TileIndex)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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#ifdef DEBUG_TILE_PUSH
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extern void dbg_push_tile(uint tile, int track);
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extern void dbg_pop_tile();
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#endif
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void TPFMode2(TrackPathFinder *tpf, uint 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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// 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 + _tileoffs_by_dir[direction]);
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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(GET_TILE_X(tile) != 255 && GET_TILE_Y(tile) != 255);
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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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#ifdef DEBUG_TILE_PUSH
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dbg_push_tile(tile, tpf->the_dir);
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#endif
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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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#ifdef DEBUG_TILE_PUSH
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dbg_pop_tile();
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#endif
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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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FindLengthOfTunnelResult FindLengthOfTunnel(uint tile, int direction, byte type)
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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 = GET_TILE_X(tile) * 16;
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y = GET_TILE_Y(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 = TILE_FROM_XY(x,y);
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if (IS_TILETYPE(tile, MP_TUNNELBRIDGE) &&
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(_map5[tile] & 0xF0) == 0 &&
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((_map5[tile]>>1)&6) == type &&
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((_map5[tile] & 3)^2) == direction &&
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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, uint tile, int direction) {
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FindLengthOfTunnelResult flotr;
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TPFSetTileBit(tpf, tile, 14);
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flotr = FindLengthOfTunnel(tile, direction, tpf->tracktype);
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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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void TPFMode1(TrackPathFinder *tpf, uint 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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uint tile_org = tile;
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260 |
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if (IS_TILETYPE(tile, MP_TUNNELBRIDGE) && (_map5[tile] & 0xF0)==0) {
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if ((_map5[tile] & 3) != direction || ((_map5[tile]>>1)&6) != 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 += _tileoffs_by_dir[direction];
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tpf->rd.cur_length++;
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268 |
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bits = GetTileTrackStatus(tile, tpf->tracktype);
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270 |
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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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276 |
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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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282 |
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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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285 |
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#ifdef DEBUG_TILE_PUSH
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dbg_push_tile(tile, tpf->the_dir);
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288 |
#endif
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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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291 |
TPFMode1(tpf, tile, _tpf_new_direction[tpf->the_dir]);
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}
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293 |
#ifdef DEBUG_TILE_PUSH
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dbg_pop_tile();
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#endif
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tpf->rd = rd;
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297 |
} while (bits != 0);
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298 |
}
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}
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300 |
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301 |
/* the next is only used when signals are checked.
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302 |
* seems to go in 2 directions simultaneously */
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303 |
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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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306 |
if (tpf->hasbit_13)
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307 |
return;
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308 |
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309 |
tile = tile_org;
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310 |
direction ^= 2;
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311 |
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312 |
bits = GetTileTrackStatus(tile, tpf->tracktype);
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313 |
bits |= (bits >> 8);
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314 |
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315 |
if ( (byte)bits != tpf->var2) {
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316 |
bits &= _bits_mask[direction];
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317 |
}
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318 |
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319 |
bits &= 0xBF;
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320 |
if (bits == 0)
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321 |
return;
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322 |
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323 |
do {
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324 |
i = FIND_FIRST_BIT(bits);
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325 |
bits = KILL_FIRST_BIT(bits);
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326 |
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327 |
tpf->the_dir = (_otherdir_mask[direction] & (byte)(1 << i)) ? (i+8) : i;
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328 |
rd = tpf->rd;
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329 |
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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331 |
TPFMode1(tpf, tile, _tpf_new_direction[tpf->the_dir]);
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332 |
}
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333 |
tpf->rd = rd;
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334 |
} while (bits != 0);
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335 |
}
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336 |
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337 |
void FollowTrack(uint tile, uint16 flags, byte direction, TPFEnumProc *enum_proc, TPFAfterProc *after_proc, void *data)
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338 |
{
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339 |
TrackPathFinder *tpf = alloca(sizeof(TrackPathFinder));
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340 |
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341 |
assert(direction < 4);
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342 |
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343 |
/* initialize path finder variables */
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344 |
tpf->userdata = data;
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345 |
tpf->enum_proc = enum_proc;
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346 |
tpf->new_link = tpf->links;
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347 |
tpf->num_links_left = 0x400;
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348 |
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349 |
tpf->rd.cur_length = 0;
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350 |
tpf->rd.depth = 0;
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351 |
tpf->rd.pft_var6 = 0;
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352 |
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|
353 |
tpf->var2 = HASBIT(flags, 15) ? 0x43 : 0xFF; /* 0x8000 */
|
|
|
354 |
|
|
|
355 |
tpf->disable_tile_hash = HASBIT(flags, 12) != 0; /* 0x1000 */
|
|
|
356 |
tpf->hasbit_13 = HASBIT(flags, 13) != 0; /* 0x2000 */
|
|
|
357 |
|
|
|
358 |
|
|
|
359 |
tpf->tracktype = (byte)flags;
|
|
|
360 |
|
|
|
361 |
if (HASBIT(flags, 11)) {
|
|
|
362 |
tpf->rd.pft_var6 = 0xFF;
|
|
|
363 |
tpf->enum_proc(tile, data, 0, 0, 0);
|
|
|
364 |
TPFMode2(tpf, tile, direction);
|
|
|
365 |
} else {
|
|
|
366 |
/* clear the hash_heads */
|
|
|
367 |
memset(tpf->hash_head, 0, sizeof(tpf->hash_head));
|
|
|
368 |
TPFMode1(tpf, tile, direction);
|
|
|
369 |
}
|
|
|
370 |
|
|
|
371 |
if (after_proc != NULL)
|
|
|
372 |
after_proc(tpf);
|
|
|
373 |
}
|
|
|
374 |
|
|
|
375 |
typedef struct {
|
|
|
376 |
TileIndex tile;
|
|
|
377 |
uint16 cur_length;
|
|
|
378 |
byte track;
|
|
|
379 |
byte depth;
|
|
|
380 |
byte state;
|
|
|
381 |
byte first_track;
|
|
|
382 |
} StackedItem;
|
|
|
383 |
|
|
|
384 |
static const byte _new_dir[6][4] = {
|
|
|
385 |
{0,0xff,2,0xff,},
|
|
|
386 |
{0xff,1,0xff,3,},
|
|
|
387 |
{0xff,0,3,0xff,},
|
|
|
388 |
{1,0xff,0xff,2,},
|
|
|
389 |
{3,2,0xff,0xff,},
|
|
|
390 |
{0xff,0xff,1,0,},
|
|
|
391 |
};
|
|
|
392 |
|
|
|
393 |
static const byte _new_track[6][4] = {
|
|
|
394 |
{0,0xff,8,0xff,},
|
|
|
395 |
{0xff,1,0xff,9,},
|
|
|
396 |
{0xff,2,10,0xff,},
|
|
|
397 |
{3,0xff,0xff,11,},
|
|
|
398 |
{12,4,0xff,0xff,},
|
|
|
399 |
{0xff,0xff,5,13,},
|
|
|
400 |
};
|
|
|
401 |
|
|
|
402 |
typedef struct HashLink {
|
|
|
403 |
TileIndex tile;
|
|
|
404 |
uint16 typelength;
|
|
|
405 |
uint16 next;
|
|
|
406 |
} HashLink;
|
|
|
407 |
|
|
|
408 |
typedef struct {
|
|
|
409 |
TPFEnumProc *enum_proc;
|
|
|
410 |
void *userdata;
|
|
|
411 |
|
|
|
412 |
byte tracktype;
|
|
|
413 |
uint maxlength;
|
|
|
414 |
|
|
|
415 |
HashLink *new_link;
|
|
|
416 |
uint num_links_left;
|
|
|
417 |
|
|
|
418 |
int nstack;
|
|
|
419 |
StackedItem stack[256]; // priority queue of stacked items
|
|
|
420 |
|
|
|
421 |
uint16 hash_head[0x400]; // hash heads. 0 means unused. 0xFFC0 = length, 0x3F = type
|
|
|
422 |
TileIndex hash_tile[0x400]; // tiles. or links.
|
|
|
423 |
|
|
|
424 |
HashLink links[0x400]; // hash links
|
|
|
425 |
|
|
|
426 |
} NewTrackPathFinder;
|
|
|
427 |
#define NTP_GET_LINK_OFFS(tpf, link) ((byte*)(link) - (byte*)tpf->links)
|
|
|
428 |
#define NTP_GET_LINK_PTR(tpf, link_offs) (HashLink*)((byte*)tpf->links + (link_offs))
|
|
|
429 |
|
|
|
430 |
#define ARR(i) tpf->stack[(i)-1]
|
|
|
431 |
|
|
|
432 |
// called after a new element was added in the queue at the last index.
|
|
|
433 |
// move it down to the proper position
|
|
|
434 |
static void INLINE HeapifyUp(NewTrackPathFinder *tpf)
|
|
|
435 |
{
|
|
|
436 |
StackedItem si;
|
|
|
437 |
int i = ++tpf->nstack;
|
|
|
438 |
|
|
|
439 |
while (i != 1 && ARR(i).cur_length < ARR(i>>1).cur_length) {
|
|
|
440 |
// the child element is larger than the parent item.
|
|
|
441 |
// swap the child item and the parent item.
|
|
|
442 |
si = ARR(i); ARR(i) = ARR(i>>1); ARR(i>>1) = si;
|
|
|
443 |
i>>=1;
|
|
|
444 |
}
|
|
|
445 |
}
|
|
|
446 |
|
|
|
447 |
// called after the element 0 was eaten. fill it with a new element
|
|
|
448 |
static void INLINE HeapifyDown(NewTrackPathFinder *tpf)
|
|
|
449 |
{
|
|
|
450 |
StackedItem si;
|
|
|
451 |
int i = 1, j;
|
|
|
452 |
int n = --tpf->nstack;
|
|
|
453 |
|
|
|
454 |
if (n == 0) return; // heap is empty so nothing to do?
|
|
|
455 |
|
|
|
456 |
// copy the last item to index 0. we use it as base for heapify.
|
|
|
457 |
ARR(1) = ARR(n+1);
|
|
|
458 |
|
|
|
459 |
while ((j=i*2) <= n) {
|
|
|
460 |
// figure out which is smaller of the children.
|
|
|
461 |
if (j != n && ARR(j).cur_length > ARR(j+1).cur_length)
|
|
|
462 |
j++; // right item is smaller
|
|
|
463 |
|
|
|
464 |
assert(i <= n && j <= n);
|
|
|
465 |
if (ARR(i).cur_length <= ARR(j).cur_length)
|
|
|
466 |
break; // base elem smaller than smallest, done!
|
|
|
467 |
|
|
|
468 |
// swap parent with the child
|
|
|
469 |
si = ARR(i); ARR(i) = ARR(j); ARR(j) = si;
|
|
|
470 |
i = j;
|
|
|
471 |
}
|
|
|
472 |
}
|
|
|
473 |
|
|
|
474 |
// mark a tile as visited and store the length of the path.
|
|
|
475 |
// if we already had a better path to this tile, return false.
|
|
|
476 |
// otherwise return true.
|
|
|
477 |
static bool NtpVisit(NewTrackPathFinder *tpf, uint tile, uint dir, uint length)
|
|
|
478 |
{
|
|
|
479 |
uint hash,head;
|
|
|
480 |
HashLink *link, *new_link;
|
|
|
481 |
|
|
|
482 |
assert(length < 1024);
|
|
|
483 |
|
|
|
484 |
hash = PATHFIND_HASH_TILE(tile);
|
|
|
485 |
|
|
|
486 |
// never visited before?
|
|
|
487 |
if ((head=tpf->hash_head[hash]) == 0) {
|
|
|
488 |
tpf->hash_tile[hash] = tile;
|
|
|
489 |
tpf->hash_head[hash] = dir | (length << 2);
|
|
|
490 |
return true;
|
|
|
491 |
}
|
|
|
492 |
|
|
|
493 |
if (head != 0xffff) {
|
|
|
494 |
if ( (TileIndex)tile == tpf->hash_tile[hash] && (head & 0x3) == dir ) {
|
|
|
495 |
|
|
|
496 |
// longer length
|
|
|
497 |
if (length >= (head >> 2)) return false;
|
|
|
498 |
|
|
|
499 |
tpf->hash_head[hash] = dir | (length << 2);
|
|
|
500 |
return true;
|
|
|
501 |
}
|
|
|
502 |
// two tiles with the same hash, need to make a link
|
|
|
503 |
// allocate a link. if out of links, handle this by returning
|
|
|
504 |
// that a tile was already visisted.
|
|
|
505 |
if (tpf->num_links_left == 0)
|
|
|
506 |
return false;
|
|
|
507 |
tpf->num_links_left--;
|
|
|
508 |
link = tpf->new_link++;
|
|
|
509 |
|
|
|
510 |
/* move the data that was previously in the hash_??? variables
|
|
|
511 |
* to the link struct, and let the hash variables point to the link */
|
|
|
512 |
link->tile = tpf->hash_tile[hash];
|
|
|
513 |
tpf->hash_tile[hash] = NTP_GET_LINK_OFFS(tpf, link);
|
|
|
514 |
|
|
|
515 |
link->typelength = tpf->hash_head[hash];
|
|
|
516 |
tpf->hash_head[hash] = 0xFFFF; /* multi link */
|
|
|
517 |
link->next = 0xFFFF;
|
|
|
518 |
} else {
|
|
|
519 |
// a linked list of many tiles,
|
|
|
520 |
// find the one corresponding to the tile, if it exists.
|
|
|
521 |
// otherwise make a new link
|
|
|
522 |
|
|
|
523 |
uint offs = tpf->hash_tile[hash];
|
|
|
524 |
do {
|
|
|
525 |
link = NTP_GET_LINK_PTR(tpf, offs);
|
|
|
526 |
if ( (TileIndex)tile == link->tile && (uint)(link->typelength & 0x3) == dir) {
|
|
|
527 |
if (length >= (uint)(link->typelength >> 2)) return false;
|
|
|
528 |
link->typelength = dir | (length << 2);
|
|
|
529 |
return true;
|
|
|
530 |
}
|
|
|
531 |
} while ((offs=link->next) != 0xFFFF);
|
|
|
532 |
}
|
|
|
533 |
|
|
|
534 |
/* get here if we need to add a new link to link,
|
|
|
535 |
* first, allocate a new link, in the same way as before */
|
|
|
536 |
if (tpf->num_links_left == 0)
|
|
|
537 |
return false;
|
|
|
538 |
tpf->num_links_left--;
|
|
|
539 |
new_link = tpf->new_link++;
|
|
|
540 |
|
|
|
541 |
/* then fill the link with the new info, and establish a ptr from the old
|
|
|
542 |
* link to the new one */
|
|
|
543 |
new_link->tile = (TileIndex)tile;
|
|
|
544 |
new_link->typelength = dir | (length << 2);
|
|
|
545 |
new_link->next = 0xFFFF;
|
|
|
546 |
|
|
|
547 |
link->next = NTP_GET_LINK_OFFS(tpf, new_link);
|
|
|
548 |
return true;
|
|
|
549 |
}
|
|
|
550 |
|
|
|
551 |
static bool NtpCheck(NewTrackPathFinder *tpf, uint tile, uint dir, uint length)
|
|
|
552 |
{
|
|
|
553 |
uint hash,head,offs;
|
|
|
554 |
HashLink *link;
|
|
|
555 |
|
|
|
556 |
hash = PATHFIND_HASH_TILE(tile);
|
|
|
557 |
head=tpf->hash_head[hash];
|
|
|
558 |
assert(head);
|
|
|
559 |
|
|
|
560 |
if (head != 0xffff) {
|
|
|
561 |
assert( tpf->hash_tile[hash] == tile && (head & 3) == dir);
|
|
|
562 |
assert( (head >> 2) <= length);
|
|
|
563 |
return length == (head >> 2);
|
|
|
564 |
}
|
|
|
565 |
|
|
|
566 |
// else it's a linked list of many tiles
|
|
|
567 |
offs = tpf->hash_tile[hash];
|
|
|
568 |
for(;;) {
|
|
|
569 |
link = NTP_GET_LINK_PTR(tpf, offs);
|
|
|
570 |
if ( (TileIndex)tile == link->tile && (uint)(link->typelength & 0x3) == dir) {
|
|
|
571 |
assert( (uint)(link->typelength >> 2) <= length);
|
|
|
572 |
return length == (uint)(link->typelength >> 2);
|
|
|
573 |
}
|
|
|
574 |
offs = link->next;
|
|
|
575 |
assert(offs != 0xffff);
|
|
|
576 |
}
|
|
|
577 |
}
|
|
|
578 |
|
|
|
579 |
|
|
|
580 |
// new more optimized pathfinder for trains...
|
|
|
581 |
void NTPEnum(NewTrackPathFinder *tpf, uint tile, uint direction)
|
|
|
582 |
{
|
|
|
583 |
uint bits, tile_org;
|
|
|
584 |
int i;
|
|
|
585 |
StackedItem si;
|
|
|
586 |
FindLengthOfTunnelResult flotr;
|
|
|
587 |
|
|
|
588 |
si.cur_length = 0;
|
|
|
589 |
si.depth = 0;
|
|
|
590 |
si.state = 0;
|
|
|
591 |
|
|
|
592 |
restart:
|
|
|
593 |
if (IS_TILETYPE(tile, MP_TUNNELBRIDGE) && (_map5[tile] & 0xF0)==0) {
|
|
|
594 |
if ( (uint)(_map5[tile] & 3) != direction || ((_map5[tile]>>1)&6) != tpf->tracktype)
|
|
|
595 |
goto popnext;
|
|
|
596 |
flotr = FindLengthOfTunnel(tile, direction, tpf->tracktype);
|
|
|
597 |
si.cur_length += flotr.length;
|
|
|
598 |
tile = flotr.tile;
|
|
|
599 |
}
|
|
|
600 |
|
|
|
601 |
// remember the start tile so we know if we're in an inf loop.
|
|
|
602 |
tile_org = tile;
|
|
|
603 |
|
|
|
604 |
for(;;) {
|
|
|
605 |
tile += _tileoffs_by_dir[direction];
|
|
|
606 |
|
|
|
607 |
// too long search length? bail out.
|
|
|
608 |
if (++si.cur_length >= tpf->maxlength)
|
|
|
609 |
goto popnext;
|
|
|
610 |
|
|
|
611 |
// not a regular rail tile?
|
|
|
612 |
if (!IS_TILETYPE(tile, MP_RAILWAY) || (bits = _map5[tile]) & 0xC0) {
|
|
|
613 |
bits = GetTileTrackStatus(tile, 0) & _tpfmode1_and[direction];
|
|
|
614 |
bits = (bits | (bits >> 8)) & 0x3F;
|
|
|
615 |
break;
|
|
|
616 |
}
|
|
|
617 |
|
|
|
618 |
// regular rail tile, determine the tracks that are actually reachable.
|
|
|
619 |
bits &= _bits_mask[direction];
|
|
|
620 |
if (bits == 0) goto popnext; // no tracks there? stop searching.
|
|
|
621 |
|
|
|
622 |
// complex tile?, let the generic handler handle that..
|
|
|
623 |
if (KILL_FIRST_BIT(bits) != 0) break;
|
|
|
624 |
|
|
|
625 |
// don't bother calling the callback when we have regular tracks only.
|
|
|
626 |
// it's usually not needed anyway. that will speed up things.
|
|
|
627 |
direction = _new_dir[FIND_FIRST_BIT(bits)][direction];
|
|
|
628 |
assert(direction != 0xFF);
|
|
|
629 |
if (tile == tile_org) goto popnext; // detect infinite loop..
|
|
|
630 |
}
|
|
|
631 |
|
|
|
632 |
if (!bits) goto popnext;
|
|
|
633 |
|
|
|
634 |
// if only one reachable track, use tail recursion optimization.
|
|
|
635 |
if (KILL_FIRST_BIT(bits) == 0) {
|
|
|
636 |
i = _new_track[FIND_FIRST_BIT(bits)][direction];
|
|
|
637 |
// call the callback
|
|
|
638 |
if (tpf->enum_proc(tile, tpf->userdata, i, si.cur_length, &si.state))
|
|
|
639 |
goto popnext; // we should stop searching in this direction.
|
|
|
640 |
|
|
|
641 |
// we should continue searching. determine new direction.
|
|
|
642 |
direction = _tpf_new_direction[i];
|
|
|
643 |
goto restart; // use tail recursion optimization.
|
|
|
644 |
}
|
|
|
645 |
|
|
|
646 |
// too high recursion depth.. bail out..
|
|
|
647 |
if (si.depth >= _patches.pf_maxdepth)
|
|
|
648 |
goto popnext;
|
|
|
649 |
|
|
|
650 |
si.depth++; // increase recursion depth.
|
|
|
651 |
|
|
|
652 |
// see if this tile was already visited..?
|
|
|
653 |
if (NtpVisit(tpf, tile, direction, si.cur_length)) {
|
|
|
654 |
// push all possible alternatives
|
|
|
655 |
si.tile = tile;
|
|
|
656 |
do {
|
|
|
657 |
si.track = _new_track[FIND_FIRST_BIT(bits)][direction];
|
|
|
658 |
|
|
|
659 |
// out of stack items, bail out?
|
|
|
660 |
if (tpf->nstack >= lengthof(tpf->stack))
|
|
|
661 |
break;
|
|
|
662 |
tpf->stack[tpf->nstack] = si;
|
|
|
663 |
HeapifyUp(tpf);
|
|
|
664 |
} while ((bits = KILL_FIRST_BIT(bits)) != 0);
|
|
|
665 |
|
|
|
666 |
// if this is the first recursion step, we need to fill the first_track member.
|
|
|
667 |
// so the code outside knows which path is better.
|
|
|
668 |
// also randomize the order in which we search through them.
|
|
|
669 |
if (si.depth == 1) {
|
|
|
670 |
uint32 r = Random();
|
|
|
671 |
assert(tpf->nstack == 2 || tpf->nstack == 3);
|
|
|
672 |
if (r&1) swap_byte(&tpf->stack[0].track, &tpf->stack[1].track);
|
|
|
673 |
if (tpf->nstack != 2) {
|
|
|
674 |
byte t = tpf->stack[2].track;
|
|
|
675 |
if (r&2) swap_byte(&tpf->stack[0].track, &t);
|
|
|
676 |
if (r&4) swap_byte(&tpf->stack[1].track, &t);
|
|
|
677 |
tpf->stack[2].first_track = tpf->stack[2].track = t;
|
|
|
678 |
}
|
|
|
679 |
tpf->stack[0].first_track = tpf->stack[0].track;
|
|
|
680 |
tpf->stack[1].first_track = tpf->stack[1].track;
|
|
|
681 |
}
|
|
|
682 |
}
|
|
|
683 |
|
|
|
684 |
popnext:
|
|
|
685 |
// where to continue.
|
|
|
686 |
do {
|
|
|
687 |
if (tpf->nstack == 0) return; // nothing left?
|
|
|
688 |
si = tpf->stack[0];
|
|
|
689 |
tile = si.tile;
|
|
|
690 |
HeapifyDown(tpf);
|
|
|
691 |
} while (
|
|
|
692 |
!NtpCheck(tpf, tile, _tpf_prev_direction[si.track], si.cur_length) || // already have better path to that tile?
|
|
|
693 |
tpf->enum_proc(tile, tpf->userdata, si.track, si.cur_length, &si.state)
|
|
|
694 |
);
|
|
|
695 |
|
|
|
696 |
direction = _tpf_new_direction[si.track];
|
|
|
697 |
goto restart;
|
|
|
698 |
}
|
|
|
699 |
|
|
|
700 |
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|
701 |
// new pathfinder for trains. better and faster.
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|
702 |
void NewTrainPathfind(uint tile, byte direction, TPFEnumProc *enum_proc, void *data, byte *cache)
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|
703 |
{
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|
704 |
if (!_patches.new_pathfinding) {
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|
705 |
FollowTrack(tile, 0x3000, direction, enum_proc, NULL, data);
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|
706 |
} else {
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|
707 |
NewTrackPathFinder *tpf;
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|
708 |
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|
709 |
tpf = alloca(sizeof(NewTrackPathFinder));
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|
710 |
tpf->userdata = data;
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|
711 |
tpf->enum_proc = enum_proc;
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|
712 |
tpf->tracktype = 0;
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|
713 |
tpf->maxlength = _patches.pf_maxlength;
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|
714 |
tpf->nstack = 0;
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|
715 |
tpf->new_link = tpf->links;
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|
716 |
tpf->num_links_left = 0x400;
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|
717 |
memset(tpf->hash_head, 0, sizeof(tpf->hash_head));
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|
718 |
|
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|
719 |
NTPEnum(tpf, tile, direction);
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|
720 |
}
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|
721 |
}
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|
722 |
|