4 files changed, 46 insertions, 13 deletions

@@ -0,0 +1,20 @@
+#include "game.h"
+
+int Game::addSprite(Sprite sprite) {
+  int id = sprites_.size();
+  sprites_.push_back(std::move(sprite));
+  spritesByY_.emplace(sprite.loc().y(), 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);
+  }
+}
\ No newline at end of file
@@ -1,6 +1,8 @@
 #ifndef GAME_H_E6F1396E
 #define GAME_H_E6F1396E
 
+#include <set>
+#include <range/v3/all.hpp>
 #include <vector>
 #include "sprite.h"
 
@@ -14,23 +16,34 @@ struct Input {
 class Game {
 public:
 
-  int addSprite(Sprite sprite) {
-    int id = sprites_.size();
-    sprites_.push_back(std::move(sprite));
-    return id;
-  }
+  int addSprite(Sprite sprite);
 
-  Sprite& getSprite(int id) {
+  const Sprite& getSprite(int id) const {
     return sprites_.at(id);
   }
 
-  std::vector<Sprite>& getSprites() {
+  const std::vector<Sprite>& getSprites() {
     return sprites_;
   }
 
+  auto spriteView() const {
+    return ranges::views::transform([&] (int id) -> const Sprite& {
+      return sprites_.at(id);
+    });
+  }
+
+  auto getSpritesByY() const {
+    return spritesByY_ | ranges::views::transform([] (const std::tuple<int, int>& val) {
+      return std::get<1>(val);
+    });
+  }
+
+  void moveSprite(int id, vec2i newLoc);
+
 private:
 
   std::vector<Sprite> sprites_;
+  std::set<std::tuple<int, int>> spritesByY_;
 };
 
 #endif /* end of include guard: GAME_H_E6F1396E */
@@ -8,7 +8,7 @@ void Party::addMember(Game& game, int spriteId) {
   newMember.spriteId = spriteId;
 
   if (index > 0) {
-    Sprite& sprite = game.getSprite(spriteId);
+    const Sprite& sprite = game.getSprite(spriteId);
 
     for (int i = 0; i < PARTY_FRAME_DELAY * index; i++) {
       newMember.nextPosition.push_back(sprite.loc());
@@ -23,7 +23,7 @@ void Party::move(Game& game, const Input& keystate) {
     return;
   }
 
-  Sprite& p1 = game.getSprite(members_[0].spriteId);
+  const Sprite& p1 = game.getSprite(members_[0].spriteId);
   vec2i pLoc = p1.loc();
 
   if (keystate.up)
@@ -47,12 +47,12 @@ void Party::move(Game& game, const Input& keystate) {
   }
 
   if (keystate.up || keystate.down || keystate.left || keystate.right) {
-    p1.loc() = pLoc;
+    game.moveSprite(members_[0].spriteId, pLoc);
 
     for (int i = 1; i < members_.size(); i++) {
-      Sprite& pNext = game.getSprite(members_[i].spriteId);
+      const Sprite& pNext = game.getSprite(members_[i].spriteId);
       members_[i].nextPosition.push_back(pLoc);
-      pNext.loc() = members_[i].nextPosition.front();
+      game.moveSprite(members_[i].spriteId, members_[i].nextPosition.front());
       members_[i].nextPosition.pop_front();
     }
   }
@@ -48,7 +48,7 @@ void Renderer::render(Game& game) {
   SDL_SetRenderDrawColor(ren_.get(), 255, 255, 255, 255);
   SDL_RenderClear(ren_.get());
 
-  for (Sprite& sprite : game.getSprites()) {
+  for (const Sprite& sprite : game.getSpritesByY() | game.spriteView()) {
     SDL_Rect dest { sprite.loc().x(), sprite.loc().y(), sprite.size().w(), sprite.size().h() };
     SDL_RenderCopy(ren_.get(), textures_.at(sprite.getTextureId()).get(), nullptr, &dest);
   }