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- /*
- * Copyright (C) 2020 Christopher J. Howard
- *
- * This file is part of Antkeeper source code.
- *
- * Antkeeper source code 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, either version 3 of the License, or
- * (at your option) any later version.
- *
- * Antkeeper source code 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 Antkeeper source code. If not, see <http://www.gnu.org/licenses/>.
- */
-
- #include "frame-scheduler.hpp"
- #include <algorithm>
-
- frame_scheduler::frame_scheduler():
- update_callback(nullptr),
- render_callback(nullptr),
- update_rate(60.0),
- update_timestep(1.0 / update_rate),
- max_frame_duration(update_timestep)
- {
- reset();
- }
-
- void frame_scheduler::set_update_callback(std::function<void(double, double)> callback)
- {
- update_callback = callback;
- }
-
- void frame_scheduler::set_render_callback(std::function<void(double)> callback)
- {
- render_callback = callback;
- }
-
- void frame_scheduler::set_update_rate(double frequency)
- {
- update_rate = frequency;
- update_timestep = 1.0 / frequency;
- }
-
- void frame_scheduler::set_max_frame_duration(double duration)
- {
- max_frame_duration = duration;
- }
-
- double frame_scheduler::get_frame_duration() const
- {
- return frame_duration;
- }
-
- void frame_scheduler::reset()
- {
- elapsed_time = 0.0;
- accumulator = 0.0;
- frame_start = std::chrono::high_resolution_clock::now();
- frame_end = frame_start;
- frame_duration = 0.0;
- }
-
- void frame_scheduler::tick()
- {
- accumulator += std::min<double>(max_frame_duration, frame_duration);
-
- while (accumulator >= update_timestep)
- {
- update_callback(elapsed_time, update_timestep);
- elapsed_time += update_timestep;
- accumulator -= update_timestep;
- }
-
- render_callback(accumulator * update_rate);
-
- frame_end = std::chrono::high_resolution_clock::now();
- frame_duration = static_cast<double>(std::chrono::duration_cast<std::chrono::microseconds>(frame_end - frame_start).count()) / 1000000.0;
- frame_start = frame_end;
- }
-
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