Mostly cleaned up world get to handle more rooms and paths, but rando_rect needs to be actually random.

matrix.hpp

@@ -3,8 +3,12 @@
 #include <queue>
 #include <string>
 #include <array>
+#include <numeric>
+#include <algorithm>
 #include <fmt/core.h>
 #include "point.hpp"
+#include "rand.hpp"
+#include "dbc.hpp"
 
 namespace matrix {
   using std::vector, std::queue, std::array;
@@ -324,4 +328,60 @@ namespace matrix {
   };
 
   using circle = circle_t<Matrix>;
+
+  template<typename MAT>
+  struct rectangle_t {
+    int x;
+    int y;
+    int left;
+    int right;
+    int width;
+    int height;
+    int bottom;
+
+    rectangle_t(MAT &mat, size_t start_x, size_t start_y, size_t width, size_t height) :
+      left(start_x),
+      width(width),
+      height(height)
+    {
+      size_t h = matrix::height(mat);
+      size_t w = matrix::width(mat);
+      y = start_y - 1;
+      x = left - 1;  // must be -1 for next()
+      right = min(start_x + width, w);
+
+      y = start_y;
+      bottom = min(start_y + height, h);
+    }
+
+    bool next() {
+      x = next_x(x, right);
+      y = next_y(x, y);
+      x = max(x, left);
+      return at_end(y, bottom);
+    }
+  };
+
+  using rectangle = rectangle_t<Matrix>;
+
+  template<typename MAT>
+  struct rando_rect_t {
+    int x;
+    int y;
+    rectangle_t<MAT> it;
+
+    rando_rect_t(MAT &mat, size_t start_x, size_t start_y, size_t width, size_t height) :
+      it{mat, start_x, start_y, width, height}
+    {
+    }
+
+    bool next() {
+      bool done = it.next();
+      x = it.x;
+      y = it.y;
+      return done;
+    }
+  };
+
+  using rando_rect = rando_rect_t<Matrix>;
 }