move class Clock to a separate unit

src/util/Clock.cpp

@@ -0,0 +1,41 @@
+#include "Clock.hpp"
+
+#include <cmath>
+
+using namespace util;
+
+Clock::Clock(int tickRate, int tickParts)
+    : tickRate(tickRate),
+      tickParts(tickParts) {
+}
+
+bool Clock::update(float delta) {
+    tickTimer += delta;
+    float delay = 1.0f / float(tickRate);    
+    if (tickTimer > delay || tickPartsUndone) {
+        if (tickPartsUndone) {
+            tickPartsUndone--;
+        } else {
+            tickTimer = std::fmod(tickTimer, delay);
+            tickPartsUndone = tickParts-1;
+        }
+        return true;
+    }
+    return false;
+}
+
+int Clock::getParts() const {
+    return tickParts;
+}
+
+int Clock::getPart() const {
+    return tickParts-tickPartsUndone-1;
+}
+
+int Clock::getTickRate() const {
+    return tickRate;
+}
+
+int Clock::getTickId() const {
+    return tickId;
+}