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Figuring out something weird about the Pathing::random_walk code.

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Zed A. Shaw 2025-03-13 23:03:14 -04:00
parent ee804581a8
commit 77f2e94515
3 changed files with 30 additions and 10 deletions
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28
pathing.cpp
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@ -74,12 +74,25 @@ void Pathing::clear_target(const Point &at) {
$input[at.y][at.x] = 1;
}
bool Pathing::random_walk(Point &out, bool random, int direction, size_t dir_count) {
/*
* This is a weird discovery, but if you randomly select a starting point on
* the 8 compass, but only check 4 directions from there, it does the best
* pathing so far. It will walk around items, navigate around enemies, find
* paths through corners, etc. If you change slice_count/dist_count to just
* 4 it fails more frequently.
*
* Look in the autowalker.cpp:path_player function for an example of what
* I'm doing. I start with 4/8 and it finds paths 99% of the time, but
* if that fails I do a full 8 direction search. This weirdly finds the
* best directions to go more often.
*/
bool Pathing::random_walk(Point &out, bool random,
int direction, size_t slice_count, size_t dist_size)
{
bool zero_found = false;
dbc::check(dir_count == 4 || dir_count == 8, "Only 8 or 4 directions allowed.");
// first 4 directions are n/s/e/w for most enemies
std::array<Point, 8> dirs{{
std::array<Point, DIRECTION_MAX> dirs{{
{out.x,out.y-1}, // north
{out.x+1,out.y}, // east
{out.x,out.y+1}, // south
@ -92,19 +105,22 @@ bool Pathing::random_walk(Point &out, bool random, int direction, size_t dir_cou
{out.x-1,out.y-1} // north west
}};
dbc::check(slice_count <= dirs.size(), "slize_count must be <= DIRECTION_MAX");
dbc::check(dist_size <= dirs.size(), "dist_size must be <= DIRECTION_MAX");
// get the current dijkstra number
int cur = $paths[out.y][out.x];
// pick a random start of directions
// BUG: is uniform inclusive of the dir.size()?
int rand_start = Random::uniform<int>(0, dir_count);
int rand_start = Random::uniform<int>(0, dist_size);
// go through all possible directions
for(size_t i = 0; i < dir_count; i++) {
for(size_t i = 0; i < slice_count; i++) {
// but start at the random start, effectively randomizing
// which valid direction to go
// BUG: this might be wrong given the above ranom from 0-size
Point dir = dirs[(i + rand_start) % dir_count];
Point dir = dirs[(i + rand_start) % dist_size];
if(!shiterator::inbounds($paths, dir.x, dir.y)) continue; //skip unpathable stuff
int weight = cur - $paths[dir.y][dir.x];