Implicit surface rendering via ray tracing
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 

171 lines
5.3 KiB

/*
* Copyright (c) 2022, NVIDIA CORPORATION. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* SPDX-FileCopyrightText: Copyright (c) 2014-2021 NVIDIA CORPORATION
* SPDX-License-Identifier: Apache-2.0
*/
#pragma once
#include <thread>
#include <condition_variable>
#include <mutex>
namespace nvh {
using DefaultDelayClock = std::chrono::steady_clock;
using DefaultDelayDuration = std::chrono::nanoseconds;
/**
* \class nvh::delayed_call class returned by delay_noreturn_for to track the thread created and possibly reset the
* delay timer.
*/
template <class Clock = DefaultDelayClock, class Duration = std::chrono::duration<double>>
class delayed_call
{
template <class ClockT, class DurationT, class Function, class... Args>
friend delayed_call<ClockT, DurationT> delay_noreturn_for(const DurationT& sleep_duration, Function&& f, Args&&... args);
public:
/** Update the thread to make the call sleep_duration from now
*
* \return True if the delay was updated before the callback was called. False otherwise.
*/
bool delay_for(const Duration& sleep_duration)
{
bool result = false;
if(m_delay)
{
std::lock_guard<std::mutex> lock(m_delay->mutex);
if(!m_delay->started)
{
auto prevUntil = m_delay->until;
m_delay->until = Clock::now() + sleep_duration;
// No need to wake up the other thread if the delay is longer. It'll keep looping while dirty is set.
if(prevUntil < m_delay->until)
m_delay->dirty = true;
else
m_delay->cv.notify_all();
}
result = !m_delay->started;
}
return result;
}
/** Cancel a delayed call
*
* \return True if the call was cancelled before running. False otherwise.
*/
bool cancel()
{
bool result = false;
if(m_delay)
{
std::lock_guard<std::mutex> lock(m_delay->mutex);
if(!m_delay->started)
{
m_delay->cancelled = true;
m_delay->cv.notify_all();
}
result = !m_delay->started;
}
return result;
}
delayed_call() = default;
delayed_call(delayed_call&& other) { *this = std::move(other); }
~delayed_call() = default;
delayed_call& operator=(delayed_call&& other)
{
m_delay = std::move(other.m_delay);
return *this;
}
// This class is movable only
delayed_call(const delayed_call& other) = delete;
delayed_call& operator=(const delayed_call& other) = delete;
private:
struct DelayData
{
std::chrono::time_point<Clock, Duration> until;
std::thread thread;
std::mutex mutex;
std::condition_variable cv;
bool dirty = true;
bool cancelled = false;
bool started = false;
~DelayData()
{
if(thread.joinable())
thread.join();
}
};
template <class Function, class... Args>
static void delayEntry(DelayData* delay, Function&& f, Args&&... args)
{
{
std::unique_lock<std::mutex> lock(delay->mutex);
std::cv_status status = std::cv_status::no_timeout;
while(!delay->cancelled && (delay->dirty || status == std::cv_status::no_timeout))
{
delay->dirty = false;
status = delay->cv.wait_until(lock, delay->until);
}
if(delay->cancelled)
return;
delay->started = true;
}
// Ignore the return value. Need to keep a std::future object if not.
(void)f(std::forward<Args>(args)...);
}
std::unique_ptr<DelayData> m_delay;
template <class Function, class... Args>
delayed_call(const Duration& sleep_duration, Function&& f, Args&&... args)
: m_delay(std::make_unique<DelayData>())
{
m_delay->until = Clock::now() + sleep_duration;
m_delay->thread =
std::thread(delayed_call::delayEntry<std::remove_reference_t<Function>&&, std::remove_reference_t<Args>&&...>,
m_delay.get(), std::forward<Function>(f), std::forward<Args>(args)...);
}
};
/**
* Delay a call to a void function for sleep_duration.
*
* \return A delayed_call object that holds the running thread.
*
* Example:
* \code
* // Create or update a delayed call to callback. Useful to consolidate multiple events into one call.
* if(!m_delayedCall.delay_for(delay))
* m_delayedCall = nvh::delay_noreturn_for(delay, callback);
* \endcode
*/
template <class Clock = DefaultDelayClock, class Duration = DefaultDelayDuration, class Function, class... Args>
delayed_call<Clock, Duration> delay_noreturn_for(const Duration& sleep_duration, Function&& f, Args&&... args)
{
return delayed_call<Clock, Duration>(sleep_duration, std::forward<Function>(f), std::forward<Args>(args)...);
}
} // namespace nvh