8 files changed, 81 insertions, 26 deletions
diff --git a/src/game.cpp b/src/game.cpp
index ebb792e..42dbd64 100644
--- a/src/game.cpp
+++ b/src/game.cpp

@@ -3,22 +3,10 @@
 int Game::addSprite(Sprite sprite) {
  int id = sprites_.size();
  sprites_.push_back(std::move(sprite));
-  spritesByY_.emplace(sprite.loc().y(), id);
+  spriteIds_.push_back(id);
  return id;
 }
-void Game::moveSprite(int id, vec2i newLoc) {
-  Sprite& sprite = sprites_.at(id);
-  bool changedY = (sprite.loc().y() != newLoc.y());
-  if (changedY) {
-    spritesByY_.erase(std::make_tuple(sprite.loc().y(), id));
-  }
-  sprite.loc() = newLoc;
-  if (changedY) {
-    spritesByY_.emplace(newLoc.y(), id);
-  }
-}
 void Game::tick() {
  if (!cameraLocked_) {
    const Sprite& follow = getSprite(followingSprite_);
diff --git a/src/game.h b/src/game.h
index a717d53..189cabb 100644
--- a/src/game.h
+++ b/src/game.h

@@ -8,6 +8,7 @@
 #include "sprite.h"
 #include "map.h"
 #include "consts.h"
+#include "transform_system.h"
 struct Input {
  bool left = false;
@@ -19,14 +20,20 @@ struct Input {
 class Game {
 public:
+  Game() : transform_(*this) {}
  int addSprite(Sprite sprite);
  const Sprite& getSprite(int id) const {
    return sprites_.at(id);
  }
-  const std::vector<Sprite>& getSprites() {
+  Sprite& getSprite(int id) {
-    return sprites_;
+    return sprites_.at(id);
+  }
+  const std::vector<int>& getSprites() {
+    return spriteIds_;
  }
  auto spriteView() const {
@@ -35,13 +42,8 @@ public:
    });
  }
-  auto getSpritesByY() const {
+  TransformSystem& getTransformSystem() { return transform_; }
-    return spritesByY_ | ranges::views::transform([] (const std::tuple<int, int>& val) {
-      return std::get<1>(val);
-    });
-  }
-  void moveSprite(int id, vec2i newLoc);
  void setSpriteState(int id, std::string state) {
    sprites_[id].setState(std::move(state));
@@ -77,8 +79,10 @@ public:
 private:
+  TransformSystem transform_;
+  std::vector<int> spriteIds_;
  std::vector<Sprite> sprites_;
-  std::set<std::tuple<int, int>> spritesByY_;
  std::unique_ptr<Map> map_;
  // Camera
diff --git a/src/main.cpp b/src/main.cpp
index 1d1583f..d182290 100644
--- a/src/main.cpp
+++ b/src/main.cpp

@@ -19,7 +19,10 @@ void loop(Renderer& renderer, Mixer& mixer) {
  int dusterSprite = game.addSprite(Sprite("../res/duster_anim.txt", renderer));
  int boneySprite = game.addSprite(Sprite("../res/boney_anim.txt", renderer));
-  game.moveSprite(lucasSprite, {32,32});
+  game.getTransformSystem().initSprite(lucasSprite, {32, 32});
+  game.getTransformSystem().initSprite(kumaSprite, {32, 32});
+  game.getTransformSystem().initSprite(dusterSprite, {32, 32});
+  game.getTransformSystem().initSprite(boneySprite, {32, 32});
  Party party;
  party.addMember(game, lucasSprite);
diff --git a/src/party.cpp b/src/party.cpp
index b7284c7..863a5d2 100644
--- a/src/party.cpp
+++ b/src/party.cpp

@@ -156,12 +156,12 @@ void Party::move(Game& game, Mixer& mixer, const Input& keystate) {
  // Move everything
  if (pLoc != p1.loc()) {
-    game.moveSprite(members_[0].spriteId, pLoc);
+    game.getTransformSystem().moveSprite(members_[0].spriteId, pLoc);
    for (int i = 1; i < members_.size(); i++) {
      const Sprite& pNext = game.getSprite(members_[i].spriteId);
      const Movement& posdir = members_[i].movement.front();
-      game.moveSprite(members_[i].spriteId, posdir.pos);
+      game.getTransformSystem().moveSprite(members_[i].spriteId, posdir.pos);
      game.setSpriteDirection(members_[i].spriteId, posdir.dir);
      members_[i].movement.pop_front();
diff --git a/src/renderer.cpp b/src/renderer.cpp
index 03d5173..b705310 100644
--- a/src/renderer.cpp
+++ b/src/renderer.cpp

@@ -109,7 +109,7 @@ void Renderer::render(Game& game) {
  SDL_RenderCopy(ren_.get(), renLay1_.get(), nullptr, nullptr);
-  for (const Sprite& sprite : game.getSpritesByY() | game.spriteView()) {
+  for (const Sprite& sprite : game.getTransformSystem().getSpritesByY() | game.spriteView()) {
    const SpriteFrame& frame = sprite.getFrame();
    const SDL_Rect& src = frame.srcRect;
    SDL_Rect dest { sprite.loc().x() - frame.center.x(), sprite.loc().y() - frame.center.y(), frame.size.w(), frame.size.h() };
diff --git a/src/system.h b/src/system.h
new file mode 100644
index 0000000..684aca9
--- /dev/null
+++ b/src/system.h

@@ -0,0 +1,7 @@
+#ifndef SYSTEM_H_6B40E1B9
+#define SYSTEM_H_6B40E1B9
+class System {
+};
+#endif /* end of include guard: SYSTEM_H_6B40E1B9 */
diff --git a/src/transform_system.cpp b/src/transform_system.cpp
new file mode 100644
index 0000000..e53fb7d
--- /dev/null
+++ b/src/transform_system.cpp

@@ -0,0 +1,20 @@
+#include "transform_system.h"
+#include "game.h"
+void TransformSystem::initSprite(int spriteId, vec2i loc) {
+  Sprite& sprite = game_.getSprite(spriteId);
+  sprite.loc() = loc;
+  spritesByY_.emplace(loc.y(), spriteId);
+}
+void TransformSystem::moveSprite(int spriteId, vec2i newLoc) {
+  Sprite& sprite = game_.getSprite(spriteId);
+  bool changedY = (sprite.loc().y() != newLoc.y());
+  if (changedY) {
+    spritesByY_.erase(std::make_tuple(sprite.loc().y(), spriteId));
+  }
+  sprite.loc() = newLoc;
+  if (changedY) {
+    spritesByY_.emplace(newLoc.y(), spriteId);
+  }
+}
diff --git a/src/transform_system.h b/src/transform_system.h
new file mode 100644
index 0000000..4616fc0
--- /dev/null
+++ b/src/transform_system.h

@@ -0,0 +1,33 @@
+#ifndef TRANSFORM_SYSTEM_H_BA2633BC
+#define TRANSFORM_SYSTEM_H_BA2633BC
+#include <range/v3/all.hpp>
+#include <set>
+#include <tuple>
+#include "system.h"
+#include "vector.h"
+class Game;
+class TransformSystem : public System {
+public:
+  TransformSystem(Game& game) : game_(game) {}
+  void initSprite(int spriteId, vec2i loc);
+  void moveSprite(int spriteId, vec2i newLoc);
+  auto getSpritesByY() const {
+    return spritesByY_ | ranges::views::transform([] (const std::tuple<int, int>& val) {
+      return std::get<1>(val);
+    });
+  }
+private:
+  Game& game_;
+  std::set<std::tuple<int, int>> spritesByY_;
+};
+#endif /* end of include guard: TRANSFORM_SYSTEM_H_BA2633BC */