diff --git a/lights.hpp b/lights.hpp
index b69523e..7a4abe3 100644
--- a/lights.hpp
+++ b/lights.hpp
@@ -40,7 +40,7 @@ namespace lighting {
     LightRender(size_t width, size_t height) :
       $width(width),
       $height(height),
-      $lightmap(height, MatrixRow(width, 0)),
+      $lightmap(height, matrix::Row(width, 0)),
       $paths(width, height)
     {}
 
diff --git a/map.cpp b/map.cpp
index 0bb06c6..3b0959a 100644
--- a/map.cpp
+++ b/map.cpp
@@ -13,7 +13,7 @@ using namespace fmt;
 Map::Map(size_t width, size_t height) :
   $width(width),
   $height(height),
-  $walls(height, MatrixRow(width, INV_WALL)),
+  $walls(height, matrix::Row(width, INV_WALL)),
   $paths(height, width)
 {}
 
@@ -54,8 +54,8 @@ bool Map::iswall(size_t x, size_t y) {
 }
 
 void Map::dump(int show_x, int show_y) {
-  matrix_dump("WALLS", walls(), show_x, show_y);
-  matrix_dump("PATHS", paths(), show_x, show_y);
+  matrix::dump("WALLS", walls(), show_x, show_y);
+  matrix::dump("PATHS", paths(), show_x, show_y);
 }
 
 bool Map::can_move(Point move_to) {
diff --git a/matrix.cpp b/matrix.cpp
index 3c45046..75ab418 100644
--- a/matrix.cpp
+++ b/matrix.cpp
@@ -3,23 +3,54 @@
 #include <fmt/core.h>
 
 using namespace fmt;
+using matrix::Matrix;
 
-void matrix_dump(const std::string &msg, Matrix &map, int show_x, int show_y) {
-  println("----------------- {}", msg);
-  for(size_t y = 0; y < map.size(); y++) {
-    for(size_t x = 0; x < map[y].size(); x++) {
-      int col = map[y][x];
+namespace matrix {
 
-      if(int(x) == show_x && int(y) == show_y) {
-        print("{:x}<", col);
-      } else if(col == WALL_PATH_LIMIT) {
+  each_cell::each_cell(Matrix &mat)
+  {
+    height = mat.size();
+    width = mat[0].size();
+  }
+
+  bool each_cell::next() {
+    x++;
+    x *= (x < width);
+    y = y + (x == 0);
+    return y < height;
+  }
+
+  each_row::each_row(Matrix &mat) :
+    $mat(mat)
+  {
+    height = $mat.size();
+    width = $mat[0].size();
+  }
+
+  bool each_row::next() {
+    x++;
+    x *= (x < width);
+    y = y + (x == 0);
+    row = x == width - 1;
+    cell = y < height ? $mat[y][x] : -1;
+    return y < height;
+  }
+
+  void dump(const std::string &msg, Matrix &map, int show_x, int show_y) {
+    println("----------------- {}", msg);
+
+    for(each_row it{map}; it.next();) {
+      if(int(it.x) == show_x && int(it.y) == show_y) {
+        print("{:x}<", it.cell);
+      } else if(it.cell == WALL_PATH_LIMIT) {
         print("# ");
-      } else if(col > 15) {
+      } else if(it.cell > 15) {
         print("* ");
       } else {
-        print("{:x} ", col);
+        print("{:x} ", it.cell);
       }
+
+      if(it.row) print("\n");
     }
-    print("\n");
   }
 }
diff --git a/matrix.hpp b/matrix.hpp
index df39410..fb13b01 100644
--- a/matrix.hpp
+++ b/matrix.hpp
@@ -2,16 +2,43 @@
 #include <vector>
 #include <string>
 
-typedef std::vector<int> MatrixRow;
-typedef std::vector<MatrixRow> Matrix;
-
-/*
- * Just a quick thing to reset a matrix to a value.
- */
-inline void matrix_assign(Matrix &out, int new_value) {
-  for(auto &row : out) {
-    row.assign(row.size(), new_value);
+namespace matrix {
+
+  typedef std::vector<int> Row;
+  typedef std::vector<Row> Matrix;
+
+  struct each_cell {
+    size_t x = ~0;
+    size_t y = ~0;
+    size_t width = 0;
+    size_t height = 0;
+    int cell = 0;
+
+    each_cell(Matrix &mat);
+    bool next();
+  };
+
+  struct each_row {
+    Matrix &$mat;
+    size_t x = ~0;
+    size_t y = ~0;
+    size_t width = 0;
+    size_t height = 0;
+    int cell = 0;
+    bool row = false;
+
+    each_row(Matrix &mat);
+    bool next();
+  };
+
+  /*
+   * Just a quick thing to reset a matrix to a value.
+   */
+  inline void assign(Matrix &out, int new_value) {
+    for(auto &row : out) {
+      row.assign(row.size(), new_value);
+    }
   }
-}
 
-void matrix_dump(const std::string &msg, Matrix &map, int show_x=-1, int show_y=-1);
+  void dump(const std::string &msg, Matrix &map, int show_x=-1, int show_y=-1);
+}
diff --git a/pathing.cpp b/pathing.cpp
index 6de97b8..473f206 100644
--- a/pathing.cpp
+++ b/pathing.cpp
@@ -28,7 +28,7 @@ inline void add_neighbors(PointList &neighbors, Matrix &closed, size_t y, size_t
 void Pathing::compute_paths(Matrix &walls) {
   INVARIANT();
   // Initialize the new array with every pixel at limit distance
-  matrix_assign($paths, WALL_PATH_LIMIT);
+  matrix::assign($paths, WALL_PATH_LIMIT);
 
   Matrix closed = walls;
   PointList starting_pixels;
@@ -77,19 +77,13 @@ void Pathing::clear_target(const Point &at) {
 }
 
 void Pathing::random_flood(const Point from, std::function<void(Point at, int dnum)> cb) {
-  int from_x = from.x;
-  int from_y = from.y;
-  int dnum = $paths[from.y][from.x];
-  cb(from, dnum);
-
-  for(int y = from_y - 1; y <= from_y + 1; y++) {
-    if(y < 0 || y >= int($height)) continue;
-    for(int x = from_x - 1; x <= from_x + 1; x++) {
-      if(x >= 0 && x <= int($width)) {
-        dnum = $paths[y][x];
-        cb({size_t(x), size_t(y)}, dnum);
-      }
-    }
+  // quick hack to try the idea
+  matrix::each_cell it{$paths};
+  it.x = from.x;
+  it.y = from.y;
+
+  while(it.next()) {
+    cb({it.x, it.y}, $paths[it.y][it.x]);
   }
 }
 
diff --git a/pathing.hpp b/pathing.hpp
index 45162f3..2f58035 100644
--- a/pathing.hpp
+++ b/pathing.hpp
@@ -3,6 +3,7 @@
 #include "matrix.hpp"
 #include <functional>
 
+using matrix::Matrix;
 
 class Pathing {
 public:
@@ -14,8 +15,8 @@ public:
   Pathing(size_t width, size_t height) :
     $width(width),
     $height(height),
-    $paths(height, MatrixRow(width, 1)),
-    $input(height, MatrixRow(width, 1))
+    $paths(height, matrix::Row(width, 1)),
+    $input(height, matrix::Row(width, 1))
   {}
 
   void compute_paths(Matrix &walls);
diff --git a/tests/map.cpp b/tests/map.cpp
index 68cf2fd..2ac78d8 100644
--- a/tests/map.cpp
+++ b/tests/map.cpp
@@ -48,8 +48,8 @@ TEST_CASE("dijkstra algo test", "[map]") {
 
     if(paths != expected) {
       println("ERROR! ------");
-      matrix_dump("EXPECTED", expected);
-      matrix_dump("RESULT", paths);
+      matrix::dump("EXPECTED", expected);
+      matrix::dump("RESULT", paths);
     }
 
     REQUIRE(map.INVARIANT());
diff --git a/tests/matrix.cpp b/tests/matrix.cpp
index 3ee0ddc..bb07bc1 100644
--- a/tests/matrix.cpp
+++ b/tests/matrix.cpp
@@ -10,117 +10,7 @@
 using namespace nlohmann;
 using namespace fmt;
 using std::string;
-
-
-
-#include <algorithm>
-#include <iostream>
-
-struct ItStep {
-  int cell;
-  size_t x;
-  size_t y;
-  bool row;
-};
-
-class MatrixIterator1 {
-  public:
-    class iterator
-    {
-    public:
-      Matrix &mat;
-      size_t x = 0;
-      size_t y = 0;
-
-      using iterator_category = std::input_iterator_tag;
-      using value_type = ItStep;
-      using difference_type = ItStep;
-      using pointer = ItStep *;
-      using reference = ItStep;
-
-      explicit iterator(Matrix &_mat)
-        : mat(_mat) {}
-
-      iterator& operator++() {
-        x++;
-        if(x < mat[0].size()) {
-          return *this;
-        } else {
-          x = 0;
-          y++;
-          return *this;
-        }
-      }
-
-      iterator operator++(int) {
-        iterator retval = *this;
-        ++(*this);
-        return retval;
-      }
-
-      bool operator==(iterator other) const {
-        return x == other.x && y == other.y;
-      }
-
-      reference operator*() const {
-        return {
-          .cell = mat[y][x],
-          .x = x,
-          .y = y,
-          .row = x >= mat[0].size() - 1
-        };
-      }
-  };
-
-  Matrix &mat;
-
-  MatrixIterator1(Matrix &mat_) :
-    mat(mat_)
-  {
-  }
-
-  iterator begin() {
-    return iterator(mat);
-  }
-
-  iterator end() {
-    iterator it(mat);
-    it.y = mat.size();
-    it.x = 0;
-    return it;
-  }
-};
-
-struct MatrixIterator2 {
-  Matrix &$mat;
-  size_t x = ~0;
-  size_t y = ~0;
-  size_t width = 0;
-  size_t height = 0;
-  int cell = 0;
-  bool row = false;
-
-  MatrixIterator2(Matrix &mat) :
-    $mat(mat)
-  {
-    height = $mat.size();
-    width = $mat[0].size();
-  }
-
-  bool next() {
-    x++;
-    x *= (x < width);
-    y = y + (x == 0);
-    row = x == width - 1;
-
-    if(y < height) {
-      cell = $mat[y][x];
-      return true;
-    } else {
-      return false;
-    }
-  }
-};
+using matrix::Matrix;
 
 TEST_CASE("basic matrix iterator", "[matrix]") {
   std::ifstream infile("./tests/dijkstra.json");
@@ -129,89 +19,30 @@ TEST_CASE("basic matrix iterator", "[matrix]") {
 
   Matrix walls = test["walls"];
 
-  matrix_dump("ITERATOR DUMP", walls);
+  matrix::dump("ITERATOR DUMP", walls);
 
-  println("VS Matrix1 ------");
+  println("VS matrix::each_row ------");
 
-  for(auto [cell, x, y, row] : MatrixIterator1(walls)) {
-    REQUIRE(walls[y][x] == cell);
-    print("{} ", cell);
-    if(row) print("\n");
+  for(matrix::each_row it{walls}; it.next();) {
+    REQUIRE(walls[it.y][it.x] == it.cell);
+    print("{} ", it.cell);
+    if(it.row) print("\n");
   }
 
-  println("VS Matrix2------");
+  // tests going through straight cells but also
+  // using two iterators on one matrix (or two)
+  matrix::each_cell cells{walls};
+  cells.next(); // kick it off
 
-  for(MatrixIterator2 mit{walls}; mit.next();) {
-    REQUIRE(walls[mit.y][mit.x] == mit.cell);
-    print("{} ", mit.cell);
-    if(mit.row) print("\n");
+  for(matrix::each_row it{walls};
+      it.next(); cells.next())
+  {
+    REQUIRE(walls[cells.y][cells.x] == it.cell);
   }
 
   println("END TEST=============");
 }
 
-
-template<long FROM, long TO>
-class Range {
-  public:
-    class iterator
-    {
-      long num = FROM;
-
-    public:
-      using iterator_category = std::input_iterator_tag;
-      using value_type = long;
-      using difference_type = long;
-      using pointer = const long *;
-      using reference = long;
-
-      explicit iterator(long _num = 0) : num(_num) {}
-
-      iterator& operator++() {
-        num = TO >= FROM ? num + 1 : num - 1;
-        return *this;
-      }
-
-      iterator operator++(int) {
-        iterator retval = *this;
-        ++(*this);
-        return retval;
-      }
-
-      bool operator==(iterator other) const {
-        return num == other.num;
-      }
-
-      bool operator!=(iterator other) const {
-        return !(*this == other);
-      }
-
-      reference operator*() const {
-        return num;
-      }
-  };
-
-  iterator begin() {
-    return iterator(FROM);
-  }
-
-  iterator end() {
-    return iterator(TO >= FROM ? TO + 1 : TO - 1);
-  }
-};
-
-TEST_CASE("basic matrix example", "[matrix]") {
-  auto range = Range<15, 25>();
-  auto itr = std::find(range.begin(), range.end(), 18);
-  std::cout << *itr << '\n';
-
-  for(long l : Range<3, 5>()) {
-    std::cout << l << ' ';
-  }
-
-  std::cout << '\n';
-}
-
 TEST_CASE("matrix_assign works", "[matrix]") {
 
 }
diff --git a/tests/pathing.cpp b/tests/pathing.cpp
index 62989be..d29a7ec 100644
--- a/tests/pathing.cpp
+++ b/tests/pathing.cpp
@@ -30,8 +30,8 @@ TEST_CASE("dijkstra algo test", "[pathing]") {
 
     REQUIRE(pathing.INVARIANT());
 
-    matrix_dump("PATHING RESULT", pathing.$paths);
-    matrix_dump("PATHING EXPECTED", expected);
+    matrix::dump("PATHING RESULT", pathing.$paths);
+    matrix::dump("PATHING EXPECTED", expected);
     REQUIRE(pathing.$paths == expected);
   }
 }
diff --git a/tests/worldbuilder.cpp b/tests/worldbuilder.cpp
index 052c6ed..c96513e 100644
--- a/tests/worldbuilder.cpp
+++ b/tests/worldbuilder.cpp
@@ -20,7 +20,7 @@ TEST_CASE("dumping and debugging", "[builder]") {
   WorldBuilder builder(map);
   builder.generate();
 
-  matrix_dump("GENERATED", map.paths());
+  matrix::dump("GENERATED", map.paths());
   map.dump();
 }
 
diff --git a/worldbuilder.cpp b/worldbuilder.cpp
index b7cefc4..b926969 100644
--- a/worldbuilder.cpp
+++ b/worldbuilder.cpp
@@ -131,12 +131,8 @@ void WorldBuilder::generate() {
     $map.$walls[hole.y][hole.x] = INV_SPACE;
   }
 
-  // invert the whole map to finish it
-  for(size_t y = 0; y < $map.$height; ++y) {
-    for(size_t x = 0; x < $map.$width; ++x) {
-      // invert the map
-      $map.$walls[y][x] = !$map.$walls[y][x];
-    }
+  for(matrix::each_cell it{$map.$walls}; it.next();) {
+    $map.$walls[it.y][it.x] = !$map.$walls[it.y][it.x];
   }
 }