Feature: Framerate display window (#6822)

Frame rate and various game loop/graphics timing measurements and graphs. Accessible via the Help menu, and can print some stats in the console via the fps command.

src/framerate_type.h

@@ -0,0 +1,67 @@
+/* $Id$ */
+
+/*
+* 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/>.
+*/
+
+#ifndef FRAMERATE_GUI_H
+#define FRAMERATE_GUI_H
+
+#include "stdafx.h"
+#include "core/enum_type.hpp"
+
+enum PerformanceElement {
+	PFE_FIRST = 0,
+	PFE_GAMELOOP = 0,  ///< Speed of gameloop processing.
+	PFE_GL_ECONOMY,    ///< Time spent processing cargo movement
+	PFE_GL_TRAINS,     ///< Time spent processing trains
+	PFE_GL_ROADVEHS,   ///< Time spend processing road vehicles
+	PFE_GL_SHIPS,      ///< Time spent processing ships
+	PFE_GL_AIRCRAFT,   ///< Time spent processing aircraft
+	PFE_GL_LANDSCAPE,  ///< Time spent processing other world features
+	PFE_GL_LINKGRAPH,  ///< Time spent waiting for link graph background jobs
+	PFE_DRAWING,       ///< Speed of drawing world and GUI.
+	PFE_DRAWWORLD,     ///< Time spent drawing world viewports in GUI
+	PFE_VIDEO,         ///< Speed of painting drawn video buffer.
+	PFE_SOUND,         ///< Speed of mixing audio samples
+	PFE_MAX,           ///< End of enum, must be last.
+};
+DECLARE_POSTFIX_INCREMENT(PerformanceElement)
+
+typedef uint64 TimingMeasurement;
+
+/**
+ * RAII class for measuring simple elements of performance.
+ * Construct an object with the appropriate element parameter when processing begins,
+ * time is automatically taken when the object goes out of scope again.
+ */
+class PerformanceMeasurer {
+	PerformanceElement elem;
+	TimingMeasurement start_time;
+public:
+	PerformanceMeasurer(PerformanceElement elem);
+	~PerformanceMeasurer();
+	void SetExpectedRate(double rate);
+	static void Paused(PerformanceElement elem);
+};
+
+/**
+ * RAII class for measuring multi-step elements of performance.
+ * At the beginning of a frame, call Reset on the element, then construct an object in the scope where
+ * each processing cycle happens. The measurements are summed between resets.
+ */
+class PerformanceAccumulator {
+	PerformanceElement elem;
+	TimingMeasurement start_time;
+public:
+	PerformanceAccumulator(PerformanceElement elem);
+	~PerformanceAccumulator();
+	static void Reset(PerformanceElement elem);
+};
+
+void ShowFramerateWindow();
+
+#endif /* FRAMERATE_GUI_H */