File diff r25013:4c02a1340d93 → r25014:e1f1bf3a062e
src/video/video_driver.cpp
Show inline comments
 
@@ -8,9 +8,9 @@
 
/** @file video_driver.cpp Common code between video driver implementations. */
 

	
 
#include "../stdafx.h"
 
#include "../debug.h"
 
#include "../core/random_func.hpp"
 
#include "../network/network.h"
 
#include "../debug.h"
 
#include "../gfx_func.h"
 
#include "../progress.h"
 
#include "../thread.h"
 
@@ -19,40 +19,84 @@
 

	
 
bool _video_hw_accel; ///< Whether to consider hardware accelerated video drivers.
 

	
 
void VideoDriver::GameLoop()
 
{
 
	this->next_game_tick += this->GetGameInterval();
 

	
 
	/* Avoid next_game_tick getting behind more and more if it cannot keep up. */
 
	auto now = std::chrono::steady_clock::now();
 
	if (this->next_game_tick < now - ALLOWED_DRIFT * this->GetGameInterval()) this->next_game_tick = now;
 

	
 
	{
 
		std::lock_guard<std::mutex> lock(this->game_state_mutex);
 

	
 
		::GameLoop();
 
	}
 
}
 

	
 
void VideoDriver::GameThread()
 
{
 
	while (!_exit_game) {
 
		this->GameLoop();
 

	
 
		auto now = std::chrono::steady_clock::now();
 
		if (this->next_game_tick > now) {
 
			std::this_thread::sleep_for(this->next_game_tick - now);
 
		} else {
 
			/* Ensure we yield this thread if drawings wants to take a lock on
 
			 * the game state. This is mainly because most OSes have an
 
			 * optimization that if you unlock/lock a mutex in the same thread
 
			 * quickly, it will never context switch even if there is another
 
			 * thread waiting to take the lock on the same mutex. */
 
			std::lock_guard<std::mutex> lock(this->game_thread_wait_mutex);
 
		}
 
	}
 
}
 

	
 
/* static */ void VideoDriver::GameThreadThunk(VideoDriver *drv)
 
{
 
	drv->GameThread();
 
}
 

	
 
void VideoDriver::StartGameThread()
 
{
 
	if (this->is_game_threaded) {
 
		this->is_game_threaded = StartNewThread(&this->game_thread, "ottd:game", &VideoDriver::GameThreadThunk, this);
 
	}
 

	
 
	DEBUG(driver, 1, "using %sthread for game-loop", this->is_game_threaded ? "" : "no ");
 
}
 

	
 
void VideoDriver::StopGameThread()
 
{
 
	if (!this->is_game_threaded) return;
 

	
 
	this->game_thread.join();
 
}
 

	
 
void VideoDriver::Tick()
 
{
 
	auto cur_ticks = std::chrono::steady_clock::now();
 

	
 
	if (cur_ticks >= this->next_game_tick) {
 
		this->next_game_tick += this->GetGameInterval();
 
		/* Avoid next_game_tick getting behind more and more if it cannot keep up. */
 
		if (this->next_game_tick < cur_ticks - ALLOWED_DRIFT * this->GetGameInterval()) this->next_game_tick = cur_ticks;
 

	
 
		/* The game loop is the part that can run asynchronously.
 
		 * The rest except sleeping can't. */
 
		this->UnlockVideoBuffer();
 
		::GameLoop();
 
		this->LockVideoBuffer();
 
	if (!this->is_game_threaded && std::chrono::steady_clock::now() >= this->next_game_tick) {
 
		this->GameLoop();
 

	
 
		/* For things like dedicated server, don't run a separate draw-tick. */
 
		if (!this->HasGUI()) {
 
			::InputLoop();
 
			UpdateWindows();
 
			::UpdateWindows();
 
			this->next_draw_tick = this->next_game_tick;
 
		}
 
	}
 

	
 
	/* Prevent drawing when switching mode, as windows can be removed when they should still appear. */
 
	if (this->HasGUI() && cur_ticks >= this->next_draw_tick && (_switch_mode == SM_NONE || _game_mode == GM_BOOTSTRAP || HasModalProgress())) {
 
	auto now = std::chrono::steady_clock::now();
 
	if (this->HasGUI() && now >= this->next_draw_tick) {
 
		this->next_draw_tick += this->GetDrawInterval();
 
		/* Avoid next_draw_tick getting behind more and more if it cannot keep up. */
 
		if (this->next_draw_tick < cur_ticks - ALLOWED_DRIFT * this->GetDrawInterval()) this->next_draw_tick = cur_ticks;
 
		if (this->next_draw_tick < now - ALLOWED_DRIFT * this->GetDrawInterval()) this->next_draw_tick = now;
 

	
 
		/* Keep the interactive randomizer a bit more random by requesting
 
		 * new values when-ever we can. */
 
		InteractiveRandom();
 

	
 
		while (this->PollEvent()) {}
 
		this->InputLoop();
 

	
 
		/* Check if the fast-forward button is still pressed. */
 
@@ -64,23 +108,41 @@ void VideoDriver::Tick()
 
			this->fast_forward_via_key = false;
 
		}
 

	
 
		::InputLoop();
 
		UpdateWindows();
 
		{
 
			/* Tell the game-thread to stop so we can have a go. */
 
			std::lock_guard<std::mutex> lock_wait(this->game_thread_wait_mutex);
 
			std::lock_guard<std::mutex> lock_state(this->game_state_mutex);
 

	
 
			this->LockVideoBuffer();
 

	
 
			while (this->PollEvent()) {}
 
			::InputLoop();
 

	
 
			/* Prevent drawing when switching mode, as windows can be removed when they should still appear. */
 
			if (_game_mode == GM_BOOTSTRAP || _switch_mode == SM_NONE || HasModalProgress()) {
 
				::UpdateWindows();
 
			}
 

	
 
			this->PopulateSystemSprites();
 
		}
 

	
 
		this->CheckPaletteAnim();
 
		this->Paint();
 

	
 
		this->UnlockVideoBuffer();
 
	}
 
}
 

	
 
void VideoDriver::SleepTillNextTick()
 
{
 
	/* See how much time there is till we have to process the next event, and try to hit that as close as possible. */
 
	auto next_tick = std::min(this->next_draw_tick, this->next_game_tick);
 
	auto next_tick = this->next_draw_tick;
 
	auto now = std::chrono::steady_clock::now();
 

	
 
	if (!this->is_game_threaded) {
 
		next_tick = min(next_tick, this->next_game_tick);
 
	}
 

	
 
	if (next_tick > now) {
 
		this->UnlockVideoBuffer();
 
		std::this_thread::sleep_for(next_tick - now);
 
		this->LockVideoBuffer();
 
	}
 
}