Timeline class.

src/CMakeLists.txt

@@ -31,6 +31,7 @@ set(Magnum_SRCS
     Renderbuffer.cpp
     Shader.cpp
     SizeTraits.cpp
+    Timeline.cpp
     TypeTraits.cpp
 
     Trade/AbstractImporter.cpp
@@ -60,6 +61,7 @@ set(Magnum_HEADERS
     SizeTraits.h
     Swizzle.h
     Texture.h
+    Timeline.h
     TypeTraits.h
 
     magnumVisibility.h)

src/Timeline.cpp

@@ -0,0 +1,53 @@
+#include "Timeline.h"
+/*
+    Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz>
+
+    This file is part of Magnum.
+
+    Magnum is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License version 3
+    only, as published by the Free Software Foundation.
+
+    Magnum 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 Lesser General Public License version 3 for more details.
+*/
+
+#include <Utility/Debug.h>
+#include <Utility/utilities.h>
+
+using namespace std::chrono;
+using namespace Corrade::Utility;
+
+namespace Magnum {
+
+void Timeline::start() {
+    running = true;
+    previousFrameTime = high_resolution_clock::now();
+    _previousFrameDuration = 0;
+}
+
+void Timeline::stop() {
+    running = false;
+    previousFrameTime = high_resolution_clock::time_point();
+    _previousFrameDuration = 0;
+}
+
+void Timeline::nextFrame() {
+    if(!running) return;
+
+    auto now = high_resolution_clock::now();
+    unsigned int duration = duration_cast<microseconds>(now-previousFrameTime).count();
+    _previousFrameDuration = duration/1e6f;
+
+    if(_previousFrameDuration < _minimalFrameTime) {
+        sleep(duration/1000);
+        now = high_resolution_clock::now();
+        _previousFrameDuration = duration_cast<microseconds>(now-previousFrameTime).count()/1e6f;
+    }
+
+    previousFrameTime = now;
+}
+
+}

src/Timeline.h

@@ -0,0 +1,91 @@
+#ifndef Magnum_Timeline_h
+#define Magnum_Timeline_h
+/*
+    Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz>
+
+    This file is part of Magnum.
+
+    Magnum is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License version 3
+    only, as published by the Free Software Foundation.
+
+    Magnum 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 Lesser General Public License version 3 for more details.
+*/
+
+#include <chrono>
+
+#include "Magnum.h"
+
+#include "magnumVisibility.h"
+
+/** @file
+ * @brief Class Magnum::Timeline
+ */
+
+namespace Magnum {
+
+/** @brief %Timeline */
+class MAGNUM_EXPORT Timeline {
+    public:
+        /**
+         * @brief Constructor
+         *
+         * Constructs stopped timeline.
+         * @see start()
+         */
+        inline constexpr Timeline(): _minimalFrameTime(0), _previousFrameDuration(0), running(false) {}
+
+        /** @brief Minimal frame time (in seconds) */
+        GLfloat minimalFrameTime() const { return _minimalFrameTime; }
+
+        /**
+         * @brief Set minimal frame time
+         *
+         * @see nextFrame()
+         */
+        void setMinimalFrameTime(GLfloat seconds) {
+            _minimalFrameTime = seconds;
+        }
+
+        /**
+         * @brief Start timeline
+         *
+         * Sets previous frame duration to `0`.
+         * @see stop(), previousFrameDuration()
+         */
+        void start();
+
+        /**
+         * @brief Stop timeline
+         */
+        void stop();
+
+        /**
+         * @brief Advance to next frame
+         *
+         * If current frame time is smaller than minimal frame time, pauses
+         * the execution for remaining time.
+         * @note This function does nothing if the timeline is stopped.
+         * @see setMinimalFrameTime()
+         */
+        void nextFrame();
+
+        /** @brief Duration of previous frame */
+        inline constexpr GLfloat previousFrameDuration() const {
+            return _previousFrameDuration;
+        }
+
+    private:
+        std::chrono::high_resolution_clock::time_point previousFrameTime;
+        GLfloat _minimalFrameTime;
+        GLfloat _previousFrameDuration;
+
+        bool running;
+};
+
+}
+
+#endif