68 lines
2.1 KiB
Plaintext
68 lines
2.1 KiB
Plaintext
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/* -*-c++-*- */
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/* osgEarth - Geospatial SDK for OpenSceneGraph
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* Copyright 2008-2014 Pelican Mapping
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* http://osgearth.org
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*
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* osgEarth is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>
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*/
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#ifndef OSGEARTH_FRAME_CLOCK
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#define OSGEARTH_FRAME_CLOCK 1
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#include "Common"
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#include <chrono>
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#include <atomic>
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namespace osgEarth
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{
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/**
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* Frame clock to keep track of time/frames independently of OSG
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*/
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class OSGEARTH_EXPORT FrameClock
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{
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public:
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//! New frame clock
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FrameClock();
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//! Seconds since creation of this object
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double getTime() const;
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//! Current frame number. This will increment each time a
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//! cull() and update() pair are called in succession.
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unsigned getFrame() const;
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//! Register a cull traversal.
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void cull();
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//! Register an update traversal. If cull() was called before
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//! the last call to update(), this will increment the frame
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//! number and return true. Otherwise it returns false, which
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//! means that update() was already called for this frame and
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//! the frame number was not incremented.
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//! (i.e., multiple calls to update in one frame will only
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//! result in the frame number incrementing once.)
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bool update();
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private:
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using Time = std::chrono::time_point<std::chrono::steady_clock>;
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Time _zero;
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Time _tick;
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unsigned _frame;
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std::atomic_bool _newframe;
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};
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} // namespace osgEarth
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#endif // OSGEARTH_FRAME_CLOCK
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