#include "constants.hpp" #include "pathing.hpp" #include "dbc.hpp" #include using std::vector; inline void add_neighbors(PointList &neighbors, Matrix &closed, size_t y, size_t x, size_t w, size_t h) { vector rows{y - 1, y, y + 1}; vector cols{x - 1, x, x + 1}; for(size_t row : rows) { for(size_t col : cols) { if((0 <= row && row < h) && (0 <= col && col < w) && closed[row][col] == 0) { closed[row][col] = 1; neighbors.push_back({.x=col, .y=row}); } } } } /* * Used https://github.com/HenrYxZ/dijkstra-map as a reference. */ void Pathing::compute_paths(Matrix &walls) { INVARIANT(); // Initialize the new array with every pixel at limit distance matrix::assign($paths, WALL_PATH_LIMIT); Matrix closed = walls; PointList starting_pixels; PointList open_pixels; // First pass: Add starting pixels and put them in closed for(size_t counter = 0; counter < $height * $width; counter++) { size_t x = counter % $width; size_t y = counter / $width; if($input[y][x] == 0) { $paths[y][x] = 0; closed[y][x] = 1; starting_pixels.push_back({x,y}); } } // Second pass: Add border to open for(auto sp : starting_pixels) { add_neighbors(open_pixels, closed, sp.y, sp.x, $width, $height); } // Third pass: Iterate filling in the open list int counter = 1; // leave this here so it's available below for(; counter < WALL_PATH_LIMIT && !open_pixels.empty(); ++counter) { PointList next_open; for(auto sp : open_pixels) { $paths[sp.y][sp.x] = counter; add_neighbors(next_open, closed, sp.y, sp.x, $width, $height); } open_pixels = next_open; } // Last pass: flood last pixels for(auto sp : open_pixels) { $paths[sp.y][sp.x] = counter; } } void Pathing::set_target(const Point &at, int value) { // FUTURE: I'll eventually allow setting this to negatives for priority $input[at.y][at.x] = value; } void Pathing::clear_target(const Point &at) { $input[at.y][at.x] = 1; } void Pathing::random_flood(const Point from, std::function cb) { // quick hack to try the idea matrix::each_cell it{$paths}; it.x = from.x; it.y = from.y; while(it.next()) { cb({it.x, it.y}, $paths[it.y][it.x]); } } bool Pathing::INVARIANT() { using dbc::check; check($paths.size() == $height, "paths wrong height"); check($paths[0].size() == $width, "paths wrong width"); check($input.size() == $height, "input wrong height"); check($input[0].size() == $width, "input wrong width"); return true; }