9 files changed, 82 insertions, 5 deletions
diff --git a/src/behaviour_system.cpp b/src/behaviour_system.cpp
new file mode 100644
index 0000000..8f17329
--- /dev/null
+++ b/src/behaviour_system.cpp

@@ -0,0 +1,32 @@
+#include "behaviour_system.h"
+#include <random>
+#include "game.h"
+#include "character_system.h"
+#include "direction.h"
+void BehaviourSystem::tick(double dt) {
+  timer_.accumulate(dt);
+  while (timer_.step()) {
+    for (int spriteId : game_.getSprites()) {
+      Sprite& sprite = game_.getSprite(spriteId);
+      if (sprite.wander) {
+        // 75% chance of changing what's happening
+        if (std::bernoulli_distribution(0.75)(game_.getRng())) {
+          // 50% chance of choosing a direction or stopping
+          if (std::bernoulli_distribution(0.5)(game_.getRng())) {
+            Direction dir;
+            switch (std::uniform_int_distribution(0,3)(game_.getRng())) {
+              case 0: dir = Direction::left; break;
+              case 1: dir = Direction::up; break;
+              case 2: dir = Direction::right; break;
+              default: dir = Direction::down; break;
+            }
+            game_.getSystem<CharacterSystem>().moveInDirection(spriteId, dir);
+          } else {
+            game_.getSystem<CharacterSystem>().stopDirecting(spriteId);
+          }
+        }
+      }
+    }
+  }
+}
diff --git a/src/behaviour_system.h b/src/behaviour_system.h
new file mode 100644
index 0000000..0eb4772
--- /dev/null
+++ b/src/behaviour_system.h

@@ -0,0 +1,24 @@
+#ifndef BEHAVIOUR_SYSTEM_H_FC908ABE
+#define BEHAVIOUR_SYSTEM_H_FC908ABE
+#include "system.h"
+#include "timer.h"
+class Game;
+class BehaviourSystem : public System {
+public:
+  static constexpr SystemKey Key = SystemKey::Behaviour;
+  explicit BehaviourSystem(Game& game) : game_(game) {}
+  void tick(double dt) override;
+private:
+  Game& game_;
+  Timer timer_ { 500 };
+};
+#endif /* end of include guard: BEHAVIOUR_SYSTEM_H_FC908ABE */
diff --git a/src/game.cpp b/src/game.cpp
index dbd314a..729e665 100644
--- a/src/game.cpp
+++ b/src/game.cpp

@@ -62,6 +62,10 @@ void Game::loadMap(std::string filename) {
      getSprite(spriteId).hasShadow = p.shadow;
    }
    getSprite(spriteId).interactionScript = p.interactionScript;
+    if (p.wander) {
+      getSystem<CharacterSystem>().initSprite(spriteId);
+      getSprite(spriteId).wander = true;
+    }
  }
  for (const Trigger& t : map_->getTriggers()) {
diff --git a/src/game.h b/src/game.h
index 9340c65..72dd337 100644
--- a/src/game.h
+++ b/src/game.h

@@ -8,6 +8,7 @@
 #include <memory>
 #include <map>
 #include <set>
+#include <random>
 #include "sprite.h"
 #include "map.h"
 #include "consts.h"
@@ -20,7 +21,7 @@ class Renderer;
 class Game {
 public:
-  explicit Game(Renderer& renderer) : font_("../res/font.txt", renderer) {}
+  Game(Renderer& renderer, std::mt19937& rng) : font_("../res/font.txt", renderer), rng_(&rng) {}
  Mixer& getMixer() { return mixer_; }
@@ -83,6 +84,8 @@ public:
  const Font& getFont() const { return font_; }
+  std::mt19937& getRng() { return *rng_; }
 private:
  Mixer mixer_;
@@ -97,6 +100,7 @@ private:
  std::map<std::string, int> spritesByAlias_;
  std::unique_ptr<Map> map_;
  Font font_;
+  std::mt19937* rng_;
 };
 #endif /* end of include guard: GAME_H_E6F1396E */
diff --git a/src/main.cpp b/src/main.cpp
index f220dc0..9f503e1 100644
--- a/src/main.cpp
+++ b/src/main.cpp

@@ -1,5 +1,6 @@
 #include <iostream>
 #include <memory>
+#include <random>
 #include "renderer.h"
 #include "game.h"
 #include "timer.h"
@@ -12,12 +13,14 @@
 #include "message_system.h"
 #include "script_system.h"
 #include "effect_system.h"
+#include "behaviour_system.h"
-void loop(Renderer& renderer) {
+void loop(Renderer& renderer, std::mt19937& rng) {
-  Game game(renderer);
+  Game game(renderer, rng);
  game.emplaceSystem<ScriptSystem>();
  game.emplaceSystem<TransformSystem>();
  game.emplaceSystem<InputSystem>();
+  game.emplaceSystem<BehaviourSystem>();
  game.emplaceSystem<CharacterSystem>();
  game.emplaceSystem<AnimationSystem>();
  game.emplaceSystem<CameraSystem>();
@@ -26,7 +29,7 @@ void loop(Renderer& renderer) {
  game.loadMap("map2");
-  vec2i warpLoc = game.getMap().getWarpPoint("debugWarp_mailboxes");
+  vec2i warpLoc = game.getMap().getWarpPoint("debugWarp_rightside");
  int lucasSprite = game.emplaceSprite("lucas");
  game.getSystem<TransformSystem>().initSprite(lucasSprite, warpLoc);
@@ -83,11 +86,14 @@ void loop(Renderer& renderer) {
 }
 int main(int, char**) {
+  std::random_device randomEngine;
+  std::mt19937 rng(randomEngine());
  try
  {
    Renderer renderer;
-    loop(renderer);
+    loop(renderer, rng);
  } catch (const sdl_error& ex)
  {
    std::cout << "SDL error (" << ex.what() << ")" << std::endl;
diff --git a/src/map.cpp b/src/map.cpp
index 3686bbd..7bff071 100644
--- a/src/map.cpp
+++ b/src/map.cpp

@@ -76,6 +76,8 @@ Map::Map(std::string_view name) : name_(name) {
              p.interactionScript = property.getStringValue();
            } else if (property.getName() == "shadow") {
              p.shadow = property.getBoolValue();
+            } else if (property.getName() == "wander") {
+              p.wander = property.getBoolValue();
            }
          }
diff --git a/src/map.h b/src/map.h
index 7dbe613..c5ecc64 100644
--- a/src/map.h
+++ b/src/map.h

@@ -24,6 +24,7 @@ struct Prototype {
  std::string animationFilename;
  std::string interactionScript;
  bool shadow = false;
+  bool wander = false;
 };
 struct Trigger {
diff --git a/src/sprite.h b/src/sprite.h
index 19dbf92..82849fa 100644
--- a/src/sprite.h
+++ b/src/sprite.h

@@ -78,6 +78,9 @@ public:
  // Input
  bool controllable = false;
  bool player = false;
+  // Behaviour
+  bool wander = false;
 };
 #endif /* end of include guard: SPRITE_H_70503825 */
diff --git a/src/system.h b/src/system.h
index 01d6cec..c0b0637 100644
--- a/src/system.h
+++ b/src/system.h

@@ -5,6 +5,7 @@ enum class SystemKey {
  Script,
  Transform,
  Input,
+  Behaviour,
  Character,
  Animation,
  Camera,