write shit

BasaltPresenter/Shared/basalt/anime_loader.cpp

@@ -1,13 +1,70 @@
 #include "anime_loader.hpp"
 
+using ::basalt::shared::math::FloatPoint;
+
 namespace basalt::shared::anime_loader {
 
-    IAnimeLoader::IAnimeLoader() {
+#pragma region Anime Loader
 
+    IAnimeLoader::IAnimeLoader() : status(AnimeLoaderStatus::Ready), time(0), last_index(0) {}
+
+    IAnimeLoader::~IAnimeLoader() {}
+
+    void IAnimeLoader::load() {
+        if (this->status != AnimeLoaderStatus::Ready) throw std::runtime_error("unexpected anime loader status");
+
+        // load by user
+        internal_load();
+
+        // check empty
+        if (this->frames.empty()) throw std::runtime_error("no anime key frames.");
+        // Get last frame index
+        auto last_pair = this->frames.end();
+        --last_pair;
+        this->last_index = last_pair->first;
+
+        // change status
+        this->status = AnimeLoaderStatus::Loaded;
     }
 
-    IAnimeLoader::~IAnimeLoader() {
+    KeyFrameSpan IAnimeLoader::tick() {
+        if (this->status != AnimeLoaderStatus::Loaded) throw std::runtime_error("unexpected anime loader status");
 
+        // Accumulate time
+        ++this->time;
+        if (this->time > this->last_index) {
+            this->time = 0;
+        }
+
+        // 首先用lower_bound获取到不小于自身的项目（肯定能获取到）
+        auto lower_bound = this->frames.lower_bound(this->time);
+        // 获取下一帧，如果没有下一帧，就转换为自身
+        auto upper_bound = lower_bound;
+        ++upper_bound;
+        if (upper_bound == this->frames.end()) {
+            upper_bound = lower_bound;
+        }
+
+        // 计算归一化时间
+        FloatPoint next_time = static_cast<FloatPoint>(this->time - lower_bound->first)
+                               / static_cast<FloatPoint>(upper_bound->first - lower_bound->first + 1);
+        FloatPoint prev_time = static_cast<FloatPoint>(1) - next_time;
+
+        // 返回结构
+        return KeyFrameSpan{
+            .prev_time = prev_time,
+            .next_time = next_time,
+            .prev_position = lower_bound->second.position,
+            .next_position = upper_bound->second.position,
+            .prev_rotation = lower_bound->second.rotation,
+            .next_rotation = upper_bound->second.rotation,
+        };
     }
 
-}
+    void IAnimeLoader::internal_load() {
+        throw std::logic_error("unimplemented function");
+    }
+
+#pragma endregion
+
+} // namespace basalt::shared::anime_loader