refactor: move Weather instance to WorldInfo

src/world/Weather.hpp

@@ -0,0 +1,63 @@
+#pragma once
+
+#include <string>
+
+#include "presets/WeatherPreset.hpp"
+
+struct Weather : Serializable {
+    WeatherPreset a {};
+    WeatherPreset b {};
+    std::string nameA;
+    std::string nameB;
+    float t = 1.0f;
+    float speed = 0.0f;
+
+    void update(float delta) {
+        t += delta * speed;
+        t = std::min(t, 1.0f);
+        b.intensity = t;
+        a.intensity = 1.0f - t;
+    }
+
+    void change(WeatherPreset preset, float time, std::string name="") {
+        std::swap(a, b);
+        std::swap(nameA, nameB);
+        b = std::move(preset);
+        t = 0.0f;
+        speed = 1.0f / std::max(time, 1.e-5f);
+        nameB = std::move(name);
+        update(0.0f);
+    }
+
+    float fogOpacity() const {
+        return b.fogOpacity * t + a.fogOpacity * (1.0f - t);
+    }
+
+    float fogDencity() const {
+        return b.fogDencity * t + a.fogDencity * (1.0f - t);
+    }
+
+    float fogCurve() const {
+        return b.fogCurve * t + a.fogCurve * (1.0f - t);
+    }
+
+    dv::value serialize() const override {
+        return dv::object({
+            {"a", a.serialize()},
+            {"b", b.serialize()},
+            {"name-a", nameA},
+            {"name-b", nameB},
+            {"t", t},
+            {"speed", speed},
+        });
+    }
+
+    void deserialize(const dv::value& src) override {
+        a.deserializeOpt(src.at("a"));
+        b.deserializeOpt(src.at("b"));
+        src.at("name-a").get(nameA);
+        src.at("name-b").get(nameB);
+        src.at("t").get(t);
+        src.at("speed").get(speed);
+    }
+};