scenes: infraestructura de la capa scenes:: (scene, timeline, sprite mover, frame animator, palette fade, surface handle, registry)

source/scenes/timeline.cpp

@@ -0,0 +1,85 @@
+#include "scenes/timeline.hpp"
+
+#include <algorithm>
+
+namespace scenes {
+
+Timeline& Timeline::step(int duration_ms, StepFn fn) {
+    Step s;
+    s.duration_ms = duration_ms;
+    s.continuous = std::move(fn);
+    steps_.push_back(std::move(s));
+    return *this;
+}
+
+Timeline& Timeline::once(OnceFn fn) {
+    Step s;
+    s.duration_ms = 0;
+    s.oneshot = std::move(fn);
+    steps_.push_back(std::move(s));
+    return *this;
+}
+
+void Timeline::flushOneShots() {
+    while (current_ < steps_.size() && steps_[current_].duration_ms == 0) {
+        auto& s = steps_[current_];
+        if (!s.entered) {
+            s.entered = true;
+            if (s.oneshot) s.oneshot();
+        }
+        ++current_;
+        elapsed_in_step_ = 0;
+    }
+}
+
+void Timeline::tick(int delta_ms) {
+    if (skipped_) return;
+    flushOneShots();
+    if (current_ >= steps_.size()) return;
+
+    auto& s = steps_[current_];
+    if (!s.entered) {
+        s.entered = true;
+        // Primer tick dins del pas: cridem amb progress=0 si hi ha callback.
+        if (s.continuous) s.continuous(0.0f);
+    }
+
+    elapsed_in_step_ += delta_ms;
+    if (elapsed_in_step_ >= s.duration_ms) {
+        // Tancament del pas: una crida final amb progress=1.
+        if (s.continuous) s.continuous(1.0f);
+        ++current_;
+        elapsed_in_step_ = 0;
+        // Pot ser que el següent pas siga una cadena de one-shots.
+        flushOneShots();
+    } else if (s.continuous) {
+        const float p = static_cast<float>(elapsed_in_step_) /
+                        static_cast<float>(std::max(1, s.duration_ms));
+        s.continuous(p);
+    }
+}
+
+void Timeline::skip() {
+    skipped_ = true;
+    current_ = steps_.size();
+}
+
+void Timeline::reset() {
+    for (auto& s : steps_) s.entered = false;
+    current_ = 0;
+    elapsed_in_step_ = 0;
+    skipped_ = false;
+}
+
+bool Timeline::done() const {
+    return skipped_ || current_ >= steps_.size();
+}
+
+float Timeline::currentProgress() const {
+    if (current_ >= steps_.size()) return 1.0f;
+    const auto& s = steps_[current_];
+    if (s.duration_ms <= 0) return 0.0f;
+    return static_cast<float>(elapsed_in_step_) / static_cast<float>(s.duration_ms);
+}
+
+}  // namespace scenes