Final move of files to a better place. Only thing in the root is very common stuff.

src/algos/dinkyecs.hpp

@@ -0,0 +1,248 @@
+#pragma once
+
+#include "dbc.hpp"
+#include <any>
+#include <functional>
+#include <queue>
+#include <tuple>
+#include <typeindex>
+#include <typeinfo>
+#include <unordered_map>
+#include <optional>
+#include <memory>
+
+namespace DinkyECS
+{
+  using Entity = unsigned long;
+
+  const Entity NONE = 0;
+
+  template <typename T>
+    struct ComponentStorage {
+      std::vector<T> data;
+    };
+
+  struct Event {
+    int event = 0;
+    Entity entity = 0;
+    std::any data;
+  };
+
+  using EntityMap = std::unordered_map<Entity, size_t>;
+  using EventQueue = std::queue<Event>;
+  using TypeMap = std::unordered_map<std::type_index, std::any>;
+
+  struct World {
+    unsigned long entity_count = NONE+1;
+    std::unordered_map<std::type_index, EntityMap> $components;
+    std::shared_ptr<TypeMap> $facts = nullptr;
+    std::unordered_map<std::type_index, EventQueue> $events;
+    std::unordered_map<std::type_index, std::any> $component_storages;
+    std::unordered_map<std::type_index, std::queue<size_t>> $free_indices;
+    std::unordered_map<Entity, bool> $constants;
+
+    World() : $facts(std::make_shared<TypeMap>())
+    {}
+
+    Entity entity() { return ++entity_count; }
+
+    void destroy(DinkyECS::Entity entity) {
+      dbc::check(!$constants.contains(entity), "trying to destroy an entity in constants");
+
+      for(auto& [tid, map] : $components) {
+
+        if(map.contains(entity)) {
+          size_t index = map.at(entity);
+          auto& free_queue = $free_indices.at(tid);
+          free_queue.push(index);
+          map.erase(entity);
+        }
+      }
+    }
+
+    void clone_into(DinkyECS::World &to_world) {
+      to_world.$constants = $constants;
+      to_world.$facts = $facts;
+      // BUG*10: entity IDs should be a global counter, not per world
+      to_world.entity_count = entity_count;
+      to_world.$component_storages = $component_storages;
+
+      for(auto [eid, is_set] : $constants) {
+        dbc::check(is_set == true, "is_set was not true? WHAT?!");
+        dbc::check(eid <= entity_count, fmt::format(
+              "eid {} is not less than entity_count {}", eid, entity_count));
+
+        for(const auto &[tid, eid_map] : $components) {
+          auto &their_map = to_world.$components[tid];
+          if(eid_map.contains(eid)) {
+            their_map.insert_or_assign(eid, eid_map.at(eid));
+          }
+        }
+      }
+    }
+
+    void make_constant(DinkyECS::Entity entity) {
+      $constants.try_emplace(entity, true);
+    }
+
+    void not_constant(DinkyECS::Entity entity) {
+      $constants.erase(entity);
+    }
+
+    template <typename Comp>
+      size_t make_component() {
+        auto &storage = component_storage_for<Comp>();
+        auto &free_queue = $free_indices.at(std::type_index(typeid(Comp)));
+        size_t index;
+
+        if(!free_queue.empty()) {
+          index = free_queue.front();
+          free_queue.pop();
+        } else {
+          storage.data.emplace_back();
+          index = storage.data.size() - 1;
+        }
+
+        return index;
+      }
+
+    template <typename Comp>
+      ComponentStorage<Comp> &component_storage_for() {
+        auto type_index = std::type_index(typeid(Comp));
+        $component_storages.try_emplace(type_index, ComponentStorage<Comp>{});
+        $free_indices.try_emplace(type_index, std::queue<size_t>{});
+        return std::any_cast<ComponentStorage<Comp> &>(
+            $component_storages.at(type_index));
+      }
+
+    template <typename Comp>
+      EntityMap &entity_map_for() {
+        return $components[std::type_index(typeid(Comp))];
+      }
+
+    template <typename Comp>
+      EventQueue &queue_map_for() {
+        return $events[std::type_index(typeid(Comp))];
+      }
+
+    template <typename Comp>
+      void remove(Entity ent) {
+        EntityMap &map = entity_map_for<Comp>();
+
+        if(map.contains(ent)) {
+          size_t index = map.at(ent);
+          auto& free_queue = $free_indices.at(std::type_index(typeid(Comp)));
+          free_queue.push(index);
+          map.erase(ent);
+        }
+      }
+
+    template <typename Comp>
+      void set_the(Comp val) {
+        $facts->insert_or_assign(std::type_index(typeid(Comp)), val);
+      }
+
+    template <typename Comp>
+      Comp &get_the() {
+        auto comp_id = std::type_index(typeid(Comp));
+        dbc::check($facts->contains(comp_id),
+            fmt::format("!!!! ATTEMPT to access world fact that hasn't "
+              "been set yet: {}",
+              typeid(Comp).name()));
+
+        // use .at to get std::out_of_range if fact not set
+        std::any &res = $facts->at(comp_id);
+        return std::any_cast<Comp &>(res);
+      }
+
+    template <typename Comp>
+      bool has_the() {
+        auto comp_id = std::type_index(typeid(Comp));
+        return $facts->contains(comp_id);
+      }
+
+    template <typename Comp>
+      void set(Entity ent, Comp val) {
+        EntityMap &map = entity_map_for<Comp>();
+
+        if(has<Comp>(ent)) {
+          get<Comp>(ent) = val;
+          return;
+        }
+
+        map.insert_or_assign(ent, make_component<Comp>());
+        get<Comp>(ent) = val;
+      }
+
+    template <typename Comp>
+      Comp &get(Entity ent) {
+        EntityMap &map = entity_map_for<Comp>();
+        auto &storage = component_storage_for<Comp>();
+        auto index = map.at(ent);
+        return storage.data[index];
+      }
+
+    template <typename Comp>
+      bool has(Entity ent) {
+        EntityMap &map = entity_map_for<Comp>();
+        return map.contains(ent);
+      }
+
+    template <typename Comp>
+      void query(std::function<void(Entity, Comp &)> cb) {
+        EntityMap &map = entity_map_for<Comp>();
+
+        for(auto &[entity, index] : map) {
+          cb(entity, get<Comp>(entity));
+        }
+      }
+
+    template <typename CompA, typename CompB>
+      void query(std::function<void(Entity, CompA &, CompB &)> cb) {
+        EntityMap &map_a = entity_map_for<CompA>();
+        EntityMap &map_b = entity_map_for<CompB>();
+
+        for(auto &[entity, index_a] : map_a) {
+          if(map_b.contains(entity)) {
+            cb(entity, get<CompA>(entity), get<CompB>(entity));
+          }
+        }
+      }
+
+    template <typename Comp>
+      void send(Comp event, Entity entity, std::any data) {
+        EventQueue &queue = queue_map_for<Comp>();
+        queue.push({event, entity, data});
+      }
+
+    template <typename Comp>
+      Event recv() {
+        EventQueue &queue = queue_map_for<Comp>();
+        Event evt = queue.front();
+        queue.pop();
+        return evt;
+      }
+
+    template <typename Comp>
+      bool has_event() {
+        EventQueue &queue = queue_map_for<Comp>();
+        return !queue.empty();
+      }
+
+    /* std::optional can't do references. Don't try it!
+     * Actually, this sucks, either delete it or have it
+     * return pointers (assuming optional can handle pointers)
+     */
+    template <typename Comp>
+      Comp* get_if(DinkyECS::Entity entity) {
+        EntityMap &map = entity_map_for<Comp>();
+        auto &storage = component_storage_for<Comp>();
+        if(map.contains(entity)) {
+          auto index = map.at(entity);
+          return &storage.data[index];
+        } else {
+          return nullptr;
+        }
+      }
+  };
+} // namespace DinkyECS

src/algos/matrix.hpp

@@ -1,5 +1,5 @@
 #pragma once
-#include "shiterator.hpp"
+#include "algos/shiterator.hpp"
 
 namespace matrix {
   using Row = shiterator::BaseRow<int>;

src/algos/maze.hpp

@@ -1,6 +1,6 @@
 #pragma once
 #include "algos/matrix.hpp"
-#include "map.hpp"
+#include "game/map.hpp"
 
 namespace maze {
 

src/algos/pathing.hpp

@@ -1,5 +1,5 @@
 #pragma once
-#include "point.hpp"
+#include "algos/point.hpp"
 #include "algos/matrix.hpp"
 #include <functional>
 

src/algos/point.hpp

@@ -0,0 +1,20 @@
+#pragma once
+#include <vector>
+
+struct Point {
+  size_t x = 0;
+  size_t y = 0;
+
+  bool operator==(const Point& other) const {
+    return other.x == x && other.y == y;
+  }
+};
+
+typedef std::vector<Point> PointList;
+
+template<> struct std::hash<Point> {
+  size_t operator()(const Point& p) const {
+    auto hasher = std::hash<int>();
+    return hasher(p.x) ^ hasher(p.y);
+  }
+};

src/algos/shiterator.hpp

@@ -0,0 +1,634 @@
+#pragma once
+#include <vector>
+#include <queue>
+#include <string>
+#include <array>
+#include <numeric>
+#include <algorithm>
+#include <fmt/core.h>
+#include "algos/point.hpp"
+#include "algos/rand.hpp"
+#include "dbc.hpp"
+
+/*
+ * # What is This Shit?
+ *
+ * Announcing the Shape Iterators, or "shiterators" for short.  The best shite
+ * for C++ for-loops since that [one youtube
+ * video](https://www.youtube.com/watch?v=rX0ItVEVjHc) told everyone to
+ * recreate SQL databases with structs. You could also say these are Shaw's
+ * Iterators, but either way they are the _shite_. Or are they shit? You decide.
+ * Maybe they're "shite"?
+ *
+ * A shiterator is a simple generator that converts 2D shapes into a 1D stream
+ * of x/y coordinates.  You give it a matrix, some parameters like start, end,
+ * etc. and each time you call `next()` you get the next viable x/y coordinate to
+ * complete the shape. This makes them far superior to _any_ existing for-loop
+ * technology because shiterators operate _intelligently_ in shapes.  Other
+ * [programming pundits](https://www.youtube.com/watch?v=tD5NrevFtbU) will say
+ * their 7000 line "easy to maintain" switch statements are better at drawing
+ * shapes, but they're wrong.  My way of making a for-loop do stuff is vastly
+ * superior because it doesn't use a switch _or_ a virtual function _or_
+ * inheritance at all.  That means they have to be the _fastest_. Feel free to run
+ * them 1000 times and bask in the glory of 1 nanosecond difference performance.
+ *
+ * It's science and shite.
+ *
+ * More importantly, shiterators are simple and easy to use.  They're so easy to
+ * use you _don't even use the 3rd part of the for-loop_.  What? You read that right,
+ * not only have I managed to eliminate _both_ massive horrible to maintain switches,
+ * and also avoided virtual functions, but I've also _eliminated one entire part
+ * of the for-loop_. This obviously makes them way faster than other inferior
+ * three-clause-loop-trash.  Just look at this comparison:
+ *
+ * ```cpp
+ * for(it = trash.begin(); it != trash.end(); it++) {
+ *     std::cout << it << std::endl;
+ * }
+ * ```
+ *
+ * ```cpp
+ * for(each_cell it{mat}; it.next();) {
+ *    std::cout << mat[it.y][it.x] << std::endl;
+ * }
+ * ```
+ *
+ * Obviously this will outperform _any_ iterator invented in the last 30 years, but the best
+ * thing about shiterators is their composability and ability to work simultaneously across
+ * multiple matrices in one loop:
+ *
+ * ```cpp
+ * for(line it{start, end}; it.next();) {
+ *    for(compass neighbor{walls, it.x, it.y}; neighbor.next();) {
+ *        if(walls[neighbor.y][neighbor.x] == 1) {
+ *          wall_update[it.y][it.x] = walls[it.y][it.x] + 10;
+ *        }
+ *    }
+ * }
+ * ```
+ *
+ * This code sample (maybe, because I didn't run it) draws a line from
+ * `start` to `end` then looks at each neighbor on a compass (north, south, east, west)
+ * at each point to see if it's set to 1.  If it is then it copies that cell over to
+ * another matrix with +10.  Why would you need this?  Your Wizard just shot a fireball
+ * down a corridor and you need to see if anything in the path is within 1 square of it.
+ *
+ * You _also_ don't even need to use a for-loop.  Yes, you can harken back to the old
+ * days when we did everything RAW inside a Duff's Device between a while-loop for
+ * that PERFORMANCE because who cares about maintenance? You're a game developer! Tests?
+ * Don't need a test if it runs fine on Sony Playstation only.  Maintenance? You're moving
+ * on to the next project in two weeks anyway right?!  Use that while-loop and a shiterator
+ * to really help that next guy:
+ *
+ * ```cpp
+ * box it{walls, center_x, center_y, 20};
+ * while(it.next()) {
+ *     walls[it.y][it.x] = 1;
+ * }
+ * ```
+ *
+ * ## Shiterator "Guarantees"
+ *
+ * Just like Rust [guarantees no memory leaks](https://github.com/pop-os/cosmic-comp/issues/1133),
+ * a shiterator tries to ensure a few things, if it can:
+ *
+ * 1. All x/y values will be within the Matrix you give it. The `line` shiterator doesn't though.
+ * 2. They try to not store anything and only calculate the math necessary to linearlize the shape.
+ * 3. You can store them and incrementally call next to get the next value.
+ * 4. You should be able to compose them together on the same Matrix or different matrices of the same dimensions.
+ * 5. Most of them will only require 1 for-loop, the few that require 2 only do this so you can draw the inside of a shape.  `circle` is like this.
+ * 6. They don't assume any particular classes or require subclassing.  As long as the type given enables `mat[y][x]` (row major) access then it'll work.
+ * 7. The matrix given to a shiterator isn't actually attached to it, so you can use one matrix to setup an iterator, then apply the x/y values to any other matrix of the same dimensions. Great for smart copying and transforming.
+ * 8. More importantly, shiterators _do not return any values from the matrix_. They only do the math for coordinates and leave it to you to work your matrix.
+ *
+ * These shiterators are used all over the game to do map rendering, randomization, drawing, nearly everything that involves a shape.
+ *
+ * ## Algorithms I Need
+ *
+ * I'm currently looking for a few algorithms, so if you know how to do these let me know:
+ *
+ * 1. _Flood fill_  This turns out to be really hard because most algorithms require keeping track of visited cells with a queue, recursion, etc.
+ * 2. _Random rectangle fill_  I have something that mostly works but it's really only random across each y-axis, then separate y-axes are randomized.
+ * 3. _Dijkstra Map_ I have a Dijkstra algorithm but it's not in this style yet.  Look in `worldbuilder.cpp` for my current implementation.
+ * 4. _Viewport_ Currently working on this but I need to have a rectangle I can move around as a viewport.
+ *
+ *
+ * ## Usage
+ *
+ * Check the `algos/matrix.hpp` for an example if you want to make it more conventient for your own type.
+ *
+ * ## Thanks
+ *
+ * Special thanks to Amit and hirdrac for their help with the math and for
+ * giving me the initial idea. hirdrac doesn't want to be held responsible for
+ * this travesty but he showed me that you can do iteration and _not_ use the
+ * weird C++ iterators.  Amit did a lot to show me how to do these calculations
+ * without branching.  Thanks to you both--and to everyone else--for helping me while I
+ * stream my development.
+ *
+ * ### SERIOUS DISCLAIMER
+ *
+ * I am horribly bad at trigonometry and graphics algorithms, so if you've got an idea to improve them
+ * or find a bug shoot me an email at help@learncodethehardway.com.
+ */
+namespace shiterator {
+  using std::vector, std::queue, std::array;
+  using std::min, std::max, std::floor;
+
+  template<typename T>
+  using BaseRow = vector<T>;
+
+  template<typename T>
+  using Base = vector<BaseRow<T>>;
+
+  template<typename T>
+  inline Base<T> make(size_t width, size_t height) {
+    Base<T> result(height, BaseRow<T>(width));
+    return result;
+  }
+
+  /*
+   * Just a quick thing to reset a matrix to a value.
+   */
+  template<typename MAT, typename VAL>
+  inline void assign(MAT &out, VAL new_value) {
+    for(auto &row : out) {
+      row.assign(row.size(), new_value);
+    }
+  }
+
+
+  /*
+   * Tells you if a coordinate is in bounds of the matrix
+   * and therefore safe to use.
+   */
+  template<typename MAT>
+  inline bool inbounds(MAT &mat, size_t x, size_t y) {
+    // since Point.x and Point.y are size_t any negatives are massive
+    return (y < mat.size()) && (x < mat[0].size());
+  }
+
+  /*
+   * Gives the width of a matrix. Assumes row major (y/x)
+   * and vector API .size().
+   */
+  template<typename MAT>
+  inline size_t width(MAT &mat) {
+    return mat[0].size();
+  }
+
+  /*
+   * Same as shiterator::width but just the height.
+   */
+  template<typename MAT>
+  inline size_t height(MAT &mat) {
+    return mat.size();
+  }
+
+  /*
+   * These are internal calculations that help
+   * with keeping track of the next x coordinate.
+   */
+  inline size_t next_x(size_t x, size_t width) {
+    return (x + 1) * ((x + 1) < width);
+  }
+
+  /*
+   * Same as next_x but updates the next y coordinate.
+   * It uses the fact that when x==0 you have a new
+   * line so increment y.
+   */
+  inline size_t next_y(size_t x, size_t y) {
+    return y + (x == 0);
+  }
+
+  /*
+   * Figures out if you're at the end of the shape,
+   * which is usually when y > height.
+   */
+  inline bool at_end(size_t y, size_t height) {
+    return y < height;
+  }
+
+  /*
+   * Determines if you're at the end of a row.
+   */
+  inline bool end_row(size_t x, size_t width) {
+    return x == width - 1;
+  }
+
+  /*
+   * Most basic shiterator. It just goes through
+   * every cell in the matrix in linear order
+   * with not tracking of anything else.
+   */
+  template<typename MAT>
+  struct each_cell_t {
+    size_t x = ~0;
+    size_t y = ~0;
+    size_t width = 0;
+    size_t height = 0;
+
+    each_cell_t(MAT &mat)
+    {
+      height = shiterator::height(mat);
+      width = shiterator::width(mat);
+    }
+
+    bool next() {
+      x = next_x(x, width);
+      y = next_y(x, y);
+      return at_end(y, height);
+    }
+  };
+
+  /*
+   * This is just each_cell_t but it sets
+   * a boolean value `bool row` so you can
+   * tell when you've reached the end of a
+   * row.  This is mostly used for printing
+   * out a matrix and similar just drawing the
+   * whole thing with its boundaries.
+   */
+  template<typename MAT>
+  struct each_row_t {
+    size_t x = ~0;
+    size_t y = ~0;
+    size_t width = 0;
+    size_t height = 0;
+    bool row = false;
+
+    each_row_t(MAT &mat) {
+      height = shiterator::height(mat);
+      width = shiterator::width(mat);
+    }
+
+    bool next() {
+      x = next_x(x, width);
+      y = next_y(x, y);
+      row = end_row(x, width);
+      return at_end(y, height);
+    }
+  };
+
+  /*
+   * This is a CENTERED box, that will create
+   * a centered rectangle around a point of a
+   * certain dimension. This kind of needs a
+   * rewrite but if you want a rectangle from
+   * a upper corner then use rectangle_t type.
+   *
+   * Passing 1 parameter for the size will make
+   * a square.
+   */
+  template<typename MAT>
+  struct box_t {
+    size_t from_x;
+    size_t from_y;
+    size_t x = 0; // these are set in constructor
+    size_t y = 0; // again, no fancy ~ trick needed
+    size_t left = 0;
+    size_t top = 0;
+    size_t right = 0;
+    size_t bottom = 0;
+
+    box_t(MAT &mat, size_t at_x, size_t at_y, size_t size) :
+      box_t(mat, at_x, at_y, size, size) {
+      }
+
+    box_t(MAT &mat, size_t at_x, size_t at_y, size_t width, size_t height) :
+      from_x(at_x), from_y(at_y)
+    {
+      size_t h = shiterator::height(mat);
+      size_t w = shiterator::width(mat);
+
+      // keeps it from going below zero
+      // need extra -1 to compensate for the first next()
+      left = max(from_x, width) - width;
+      x = left - 1;  // must be -1 for next()
+      // keeps it from going above width
+      right = min(from_x + width + 1, w);
+
+      // same for these two
+      top = max(from_y, height) - height;
+      y = top - (left == 0);
+      bottom = min(from_y + height + 1, h);
+    }
+
+    bool next() {
+      // calc next but allow to go to 0 for next
+      x = next_x(x, right);
+      // x will go to 0, which signals new line
+      y = next_y(x, y);  // this must go here
+      // if x==0 then this moves it to min_x
+      x = max(x, left);
+      // and done
+
+      return at_end(y, bottom);
+    }
+
+    /*
+     * This was useful for doing quick lighting
+     * calculations, and I might need to implement
+     * it in other shiterators. It gives the distance
+     * to the center from the current x/y.
+     */
+    float distance() {
+      int dx = from_x - x;
+      int dy = from_y - y;
+
+      return sqrt((dx * dx) + (dy * dy));
+    }
+  };
+
+  /*
+   * Stupid simple compass shape North/South/East/West.
+   * This comes up a _ton_ when doing searching, flood
+   * algorithms, collision, etc.  Probably not the
+   * fastest way to do it but good enough.
+   */
+  template<typename MAT>
+  struct compass_t {
+    size_t x = 0; // these are set in constructor
+    size_t y = 0; // again, no fancy ~ trick needed
+    array<int, 4> x_dirs{0, 1, 0, -1};
+    array<int, 4> y_dirs{-1, 0, 1, 0};
+    size_t max_dirs=0;
+    size_t dir = ~0;
+
+    compass_t(MAT &mat, size_t x, size_t y) :
+      x(x), y(y)
+    {
+      array<int, 4> x_in{0, 1, 0, -1};
+      array<int, 4> y_in{-1, 0, 1, 0};
+
+      for(size_t i = 0; i < 4; i++) {
+        int nx = x + x_in[i];
+        int ny = y + y_in[i];
+        if(shiterator::inbounds(mat, nx, ny)) {
+          x_dirs[max_dirs] = nx;
+          y_dirs[max_dirs] = ny;
+          max_dirs++;
+        }
+      }
+    }
+
+    bool next() {
+      dir++;
+      if(dir < max_dirs) {
+        x = x_dirs[dir];
+        y = y_dirs[dir];
+        return true;
+      } else {
+        return false;
+      }
+    }
+  };
+
+  /*
+   * Draws a line from start to end using a algorithm from
+   * https://en.wikipedia.org/wiki/Bresenham%27s_line_algorithm
+   * No idea if the one I picked is best but it's the one
+   * that works in the shiterator requirements and produced
+   * good results.
+   *
+   * _WARNING_: This one doesn't check if the start/end are
+   * within your Matrix, as it's assumed _you_ did that
+   * already.
+   */
+  struct line {
+    int x;
+    int y;
+    int x1;
+    int y1;
+    int sx;
+    int sy;
+    int dx;
+    int dy;
+    int error;
+
+    line(Point start, Point end) :
+        x(start.x), y(start.y),
+        x1(end.x), y1(end.y)
+    {
+      dx = std::abs(x1 - x);
+      sx = x < x1 ? 1 : -1;
+      dy = std::abs(y1 - y) * -1;
+      sy = y < y1 ? 1 : -1;
+      error = dx + dy;
+    }
+
+    bool next() {
+      if(x != x1 || y != y1) {
+        int e2 = 2 * error;
+
+        if(e2 >= dy) {
+          error = error + dy;
+          x = x + sx;
+        }
+
+        if(e2 <= dx) {
+          error = error + dx;
+          y = y + sy;
+        }
+        return true;
+      } else {
+        return false;
+      }
+    }
+  };
+
+  /*
+   * Draws a simple circle using a fairly naive algorithm
+   * but one that actually worked.  So, so, so, so many
+   * circle drawing algorithms described online don't work
+   * or are flat wrong.  Even the very best I could find
+   * did overdrawing of multiple lines or simply got the
+   * math wrong.  Keep in mind, _I_ am bad at this trig math
+   * so if I'm finding errors in your circle drawing then
+   * you got problems.
+   *
+   * This one is real simple, and works. If you got better
+   * then take the challenge but be ready to get it wrong.
+   */
+  template<typename MAT>
+  struct circle_t {
+    float center_x;
+    float center_y;
+    float radius = 0.0f;
+    int y = 0;
+    int dx = 0;
+    int dy = 0;
+    int left = 0;
+    int right = 0;
+    int top = 0;
+    int bottom = 0;
+    int width = 0;
+    int height = 0;
+
+    circle_t(MAT &mat, Point center, float radius) :
+      center_x(center.x), center_y(center.y), radius(radius)
+    {
+      width = shiterator::width(mat);
+      height = shiterator::height(mat);
+      top = max(int(floor(center_y - radius)), 0);
+      bottom = min(int(floor(center_y + radius)), height - 1);
+
+      y = top;
+    }
+
+    bool next() {
+      y++;
+      if(y <= bottom) {
+        dy = y - center_y;
+        dx = floor(sqrt(radius * radius - dy * dy));
+        left = max(0, int(center_x) - dx);
+        right = min(width, int(center_x) + dx + 1);
+        return true;
+      } else {
+        return false;
+      }
+    }
+  };
+
+  /*
+   * Basic rectangle shiterator, and like box and rando_rect_t you can
+   * pass only 1 parameter for size to do a square.
+   */
+  template<typename MAT>
+  struct rectangle_t {
+    int x;
+    int y;
+    int top;
+    int left;
+    int width;
+    int height;
+    int right;
+    int bottom;
+
+    rectangle_t(MAT &mat, size_t start_x, size_t start_y, size_t size) :
+      rectangle_t(mat, start_x, start_y, size, size) {
+      }
+
+    rectangle_t(MAT &mat, size_t start_x, size_t start_y, size_t width, size_t height) :
+      top(start_y),
+      left(start_x),
+      width(width),
+      height(height)
+    {
+      size_t h = shiterator::height(mat);
+      size_t w = shiterator::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);
+    }
+  };
+
+  /*
+   * Same as rando_rect_t but it uses a centered box.
+   */
+  template<typename MAT>
+  struct rando_box_t {
+    size_t x;
+    size_t y;
+    size_t x_offset;
+    size_t y_offset;
+    box_t<MAT> it;
+
+    rando_box_t(MAT &mat, size_t start_x, size_t start_y, size_t size) :
+      it{mat, start_x, start_y, size}
+    {
+      x_offset = Random::uniform(size_t(0), it.right);
+      y_offset = Random::uniform(size_t(0), it.bottom);
+    }
+
+    bool next() {
+      bool done = it.next();
+      x = it.left + ((it.x + x_offset) % it.right);
+      y = it.top + ((it.y + y_offset) % it.bottom);
+      return done;
+    }
+  };
+
+  /*
+   * WIP:  This one is used to place entities randomly but
+   * could be used for effects like random destruction of floors.
+   * It simply "wraps" the rectangle_t but randomizes the x/y values
+   * using a random starting point.  This makes it random across the
+   * x-axis but only partially random across the y.
+   */
+  template<typename MAT>
+  struct rando_rect_t {
+    int x;
+    int y;
+    int x_offset;
+    int y_offset;
+    rectangle_t<MAT> it;
+
+    rando_rect_t(MAT &mat, size_t start_x, size_t start_y, size_t size) :
+      rando_rect_t(mat, start_x, start_y, size, size) {
+      }
+
+    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}
+    {
+      x_offset = Random::uniform(0, int(width));
+      y_offset = Random::uniform(0, int(height));
+    }
+
+    bool next() {
+      bool done = it.next();
+      x = it.left + ((it.x + x_offset) % it.width);
+      y = it.top + ((it.y + y_offset) % it.height);
+      return done;
+    }
+  };
+
+  /*
+   * BROKEN: I'm actually not sure what I'm trying to
+   * do here yet.
+   */
+  template<typename MAT>
+  struct viewport_t {
+    Point start;
+    // this is the point in the map
+    size_t x;
+    size_t y;
+    // this is the point inside the box, start at 0
+    size_t view_x = ~0;
+    size_t view_y = ~0;
+    // viewport width/height
+    size_t width;
+    size_t height;
+
+    viewport_t(MAT &mat, Point start, int max_x, int max_y) :
+      start(start),
+      x(start.x-1),
+      y(start.y-1)
+    {
+      width = std::min(size_t(max_x), shiterator::width(mat) - start.x);
+      height = std::min(size_t(max_y), shiterator::height(mat) - start.y);
+      fmt::println("viewport_t max_x, max_y {},{} vs matrix {},{}, x={}, y={}",
+          max_x, max_y, shiterator::width(mat), shiterator::height(mat), x, y);
+    }
+
+    bool next() {
+      y = next_y(x, y);
+      x = next_x(x, width);
+      view_x = next_x(view_x, width);
+      view_y = next_y(view_x, view_y);
+      return at_end(y, height);
+    }
+  };
+
+}

src/algos/simplefsm.hpp

@@ -0,0 +1,32 @@
+#pragma once
+
+#include <fmt/core.h>
+
+#ifndef FSM_DEBUG
+#define FSM_STATE(C, S, E, ...) case C::S: S(E, ##__VA_ARGS__); break
+#else
+static int last_event=-1;
+#define FSM_STATE(C, S, E, ...) case C::S: if(last_event != int(E)) { last_event = int(E); fmt::println(">> " #C " " #S " event={}, state={}", int(E), int($state));}; S(E, ##__VA_ARGS__); break
+#endif
+
+template<typename S, typename E>
+class DeadSimpleFSM {
+protected:
+  // BUG: don't put this in your class because state() won't work
+ S $state = S::START;
+
+public:
+  template<typename... Types>
+  void event(E event, Types... args);
+
+  void state(S next_state) {
+#ifdef FSM_DEBUG
+    fmt::println("<< STATE: {} -> {}", int($state), int(next_state));
+#endif
+    $state = next_state;
+  }
+
+  bool in_state(S state) {
+    return $state == state;
+  }
+};

src/algos/spatialmap.hpp

@@ -1,9 +1,9 @@
 #pragma once
 #include <vector>
 #include <unordered_map>
-#include "map.hpp"
-#include "dinkyecs.hpp"
-#include "point.hpp"
+#include "game/map.hpp"
+#include "algos/dinkyecs.hpp"
+#include "algos/point.hpp"
 
 struct CollisionData {
   DinkyECS::Entity entity = DinkyECS::NONE;