Done

stopwatch.c

@@ -1,9 +1,9 @@
 /*-----------------------------------------------------------------------------
- *				HTBLA-Leonding / Class: <your class name here>
+ *				HTBLA-Leonding / Class: 2IHIF
  *-----------------------------------------------------------------------------
- * Exercise Number: S07
+ * Exercise Number: S05
  * Title:			Stopwatch
- * Author:			*/<your name>;/*
+ * Author:			Marc Tismonar
  *-----------------------------------------------------------------------------
  * Description:
  * Implementation of a simple stopwatch
@@ -25,3 +25,71 @@
  *     -> seconds = ticks / CLOCK_PER_SEC
  *   microseconds are s * 10^-6
  */
+
+static clock_t start_time = 0;
+static clock_t passed_time = 0;
+static bool is_active = false;
+
+/**
+ * Starts taking the time. This function always starts at 0.
+ */
+void stopwatch_start()
+{
+    start_time = clock();
+    passed_time = 0;
+    is_active = true;
+}
+
+/**
+ * Stops or pauses taking the time. Time measurement can be resumed 
+ * via `stopwatch_resume`.
+ */
+void stopwatch_stop()
+{
+    if (!is_active) {
+        return;
+    }
+
+    passed_time += clock() - start_time;
+    is_active = false;
+}
+
+/**
+ * Resumes taking the time. The previously measured time value is
+ * used as start value.
+ */
+void stopwatch_resume()
+{
+    if (is_active) {
+        return;
+    }
+
+    start_time = clock();
+    is_active = true;
+}
+
+/**
+ * Determines whether or not the stopwatch takes the time.
+ * @return True if the stopwatch is measuring, false otherwise.
+ */
+bool stopwatch_is_active()
+{
+    return is_active;
+}
+
+/**
+ * The measured time in microseconds.
+ * 
+ * @return Either the processor time elapsed since start_stopwatch() has been called or
+ * the processor time elapsed between the calls of start_stopwatch() and stop_stopwatch().
+ */
+double stopwatch_get_elapsed_time()
+{
+    clock_t total_time = passed_time;
+    
+    if (is_active) {
+        total_time += clock() - start_time;
+    }
+    
+    return ((double)total_time / CLOCKS_PER_SEC) * 1000000.0;
+}