Add: draw the screen at a steady pace, also during fast-forward

During fast-forward, the game was drawing as fast as it could. This
means that the fast-forward was limited also by how fast we could
draw, something that people in general don't expect.

To give an extreme case, if you are fully zoomed out on a busy
map, fast-forward would be mostly limited because of the time it
takes to draw the screen.

By decoupling the draw-tick and game-tick, we can keep the pace
of the draw-tick the same while speeding up the game-tick. To use
the extreme case as example again, if you are fully zoomed out
now, the screen only redraws 33.33 times per second, fast-forwarding
or not. This means fast-forward is much more likely to go at the
same speed, no matter what you are looking at.
This commit is contained in:
Patric Stout
2021-02-17 15:04:46 +01:00
committed by Patric Stout
parent 5bfa014505
commit c81c6e5eb7
9 changed files with 117 additions and 99 deletions

View File

@@ -1135,7 +1135,8 @@ void VideoDriver_Win32::MainLoop()
MSG mesg;
auto cur_ticks = std::chrono::steady_clock::now();
auto last_realtime_tick = cur_ticks;
auto next_tick = cur_ticks;
auto next_game_tick = cur_ticks;
auto next_draw_tick = cur_ticks;
std::thread draw_thread;
std::unique_lock<std::recursive_mutex> draw_lock;
@@ -1205,8 +1206,21 @@ void VideoDriver_Win32::MainLoop()
last_realtime_tick += delta;
}
if (cur_ticks >= next_tick || (_fast_forward && !_pause_mode)) {
next_tick = cur_ticks + std::chrono::milliseconds(MILLISECONDS_PER_TICK);
if (cur_ticks >= next_game_tick || (_fast_forward && !_pause_mode)) {
next_game_tick = cur_ticks + std::chrono::milliseconds(MILLISECONDS_PER_TICK);
/* Flush GDI buffer to ensure we don't conflict with the drawing thread. */
GdiFlush();
/* The game loop is the part that can run asynchronously.
* The rest except sleeping can't. */
if (_draw_threaded) draw_lock.unlock();
GameLoop();
if (_draw_threaded) draw_lock.lock();
}
if (cur_ticks >= next_draw_tick) {
next_draw_tick = cur_ticks + std::chrono::milliseconds(MILLISECONDS_PER_TICK);
bool old_ctrl_pressed = _ctrl_pressed;
@@ -1226,30 +1240,23 @@ void VideoDriver_Win32::MainLoop()
if (old_ctrl_pressed != _ctrl_pressed) HandleCtrlChanged();
/* Flush GDI buffer to ensure we don't conflict with the drawing thread. */
GdiFlush();
/* The game loop is the part that can run asynchronously.
* The rest except sleeping can't. */
if (_draw_threaded) draw_lock.unlock();
GameLoop();
if (_draw_threaded) draw_lock.lock();
if (_force_full_redraw) MarkWholeScreenDirty();
UpdateWindows();
CheckPaletteAnim();
} else {
/* Flush GDI buffer to ensure we don't conflict with the drawing thread. */
GdiFlush();
/* Release the thread while sleeping */
if (_draw_threaded) draw_lock.unlock();
CSleep(1);
if (_draw_threaded) draw_lock.lock();
InputLoop();
UpdateWindows();
CheckPaletteAnim();
}
NetworkDrawChatMessage();
DrawMouseCursor();
if (!_fast_forward || _pause_mode) {
/* Flush GDI buffer to ensure we don't conflict with the drawing thread. */
GdiFlush();
if (_draw_mutex != nullptr) draw_lock.unlock();
CSleep(1);
if (_draw_mutex != nullptr) draw_lock.lock();
}
}