Change: Use GUITimer class instead of bare int/uints.

1 files changed, 65 insertions, 0 deletions

diff --git a/src/guitimer_func.h b/src/guitimer_func.h
new file mode 100644
index 000000000..44ce04228
--- /dev/null
+++ b/src/guitimer_func.h
@@ -0,0 +1,65 @@
+/* $Id$ */
+
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
+ * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** @file guitimer_func.h GUI Timers. */
+
+#ifndef GUITIMER_FUNC_H
+#define GUITIMER_FUNC_H
+
+class GUITimer
+{
+protected:
+	uint timer;
+	uint interval;
+
+public:
+	GUITimer() : timer(0), interval(0) { }
+	explicit GUITimer(uint interval) : timer(0), interval(interval) { }
+
+	inline bool HasElapsed() const
+	{
+		return this->interval == 0;
+	}
+
+	inline void SetInterval(uint interval)
+	{
+		this->timer = 0;
+		this->interval = interval;
+	}
+
+	/**
+	 * Count how many times the interval has elapsed.
+	 * Use to ensure a specific amount of events happen within a timeframe, e.g. for animation.
+	 * @param delta Time since last test.
+	 * @return Number of times the interval has elapsed.
+	 */
+	inline uint CountElapsed(uint delta)
+	{
+		if (this->interval == 0) return 0;
+		uint count = delta / this->interval;
+		if (this->timer + (delta % this->interval) >= this->interval) count++;
+		this->timer = (this->timer + delta) % this->interval;
+		return count;
+	}
+
+	/**
+	 * Test if a timer has elapsed.
+	 * Use to ensure an event happens only once within a timeframe, e.g. for window updates.
+	 * @param delta Time since last test.
+	 * @return True iff the timer has elapsed.
+	 */
+	inline bool Elapsed(uint delta)
+	{
+		if (this->CountElapsed(delta) == 0) return false;
+		this->SetInterval(0);
+		return true;
+	}
+};
+
+#endif /* GUITIMER_FUNC_H */