Brought over a bunch of code from the roguelike and now will use it to generate a random map.

pathing.cpp

@@ -0,0 +1,86 @@
+#include "constants.hpp"
+#include "pathing.hpp"
+#include "dbc.hpp"
+#include <vector>
+
+using std::vector;
+
+inline void add_neighbors(PointList &neighbors, Matrix &closed, size_t y, size_t x) {
+  for(matrix::box it{closed, x, y, 1}; it.next();) {
+    if(closed[it.y][it.x] == 0) {
+      closed[it.y][it.x] = 1;
+      neighbors.emplace_back(it.x, it.y);
+    }
+  }
+}
+
+/*
+ * Used https://github.com/HenrYxZ/dijkstra-map as a reference.
+ */
+void Pathing::compute_paths(Matrix &walls) {
+  INVARIANT();
+  dbc::check(walls[0].size() == $width,
+      fmt::format("Pathing::compute_paths called with walls.width={} but paths $width={}", walls[0].size(), $width));
+
+  dbc::check(walls.size() == $height,
+      fmt::format("Pathing::compute_paths called with walls.height={} but paths $height={}", walls[0].size(), $height));
+
+  // Initialize the new array with every pixel at limit distance
+  matrix::assign($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.emplace_back(x,y);
+    }
+  }
+
+  // Second pass: Add border to open
+  for(auto sp : starting_pixels) {
+    add_neighbors(open_pixels, closed, sp.y, sp.x);
+  }
+
+  // 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);
+    }
+    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) {
+  $input[at.y][at.x] = 1;
+}
+
+bool Pathing::INVARIANT() {
+  using dbc::check;
+
+  check($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;
+}