migrat Logo a time based

source/utils/delta_timer.cpp

@@ -0,0 +1,39 @@
+#include "utils/delta_timer.hpp"
+
+DeltaTimer::DeltaTimer() noexcept
+    : last_counter_(SDL_GetPerformanceCounter()),
+      perf_freq_(static_cast<double>(SDL_GetPerformanceFrequency())),
+      time_scale_(1.0f) {
+}
+
+float DeltaTimer::tick() noexcept {
+    const Uint64 now = SDL_GetPerformanceCounter();
+    const Uint64 diff = (now > last_counter_) ? (now - last_counter_) : 0;
+    last_counter_ = now;
+    const double seconds = static_cast<double>(diff) / perf_freq_;
+    return static_cast<float>(seconds * static_cast<double>(time_scale_));
+}
+
+float DeltaTimer::peek() const noexcept {
+    const Uint64 now = SDL_GetPerformanceCounter();
+    const Uint64 diff = (now > last_counter_) ? (now - last_counter_) : 0;
+    const double seconds = static_cast<double>(diff) / perf_freq_;
+    return static_cast<float>(seconds * static_cast<double>(time_scale_));
+}
+
+void DeltaTimer::reset(Uint64 counter) noexcept {
+    if (counter == 0) {
+        last_counter_ = SDL_GetPerformanceCounter();
+    } else {
+        last_counter_ = counter;
+    }
+}
+
+void DeltaTimer::setTimeScale(float scale) noexcept {
+    time_scale_ = std::max(scale, 0.0f);
+}
+
+float DeltaTimer::getTimeScale() const noexcept {
+    return time_scale_;
+}
+