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;
+}

src/util/Clock.hpp

@@ -0,0 +1,24 @@
+#ifndef UTIL_CLOCK_HPP_
+#define UTIL_CLOCK_HPP_
+
+namespace util {
+    class Clock {
+        int tickRate;
+        int tickParts;
+
+        float tickTimer = 0.0f;
+        int tickId = 0;
+        int tickPartsUndone = 0;
+    public:
+        Clock(int tickRate, int tickParts);
+
+        bool update(float delta);
+
+        int getParts() const;
+        int getPart() const;
+        int getTickRate() const;
+        int getTickId() const;
+    };
+}
+
+#endif // UTIL_CLOCK_HPP_