Codechange: unroll the SDL2 main loop

This commit prepares for the next commit, as Emscripten needs to
have a way to trigger a single iteration of the main loop. To
keep the real changes more clear, this commit only unrolls the
loop, and makes no changes to the logic itself.
This commit is contained in:
Patric Stout 2020-12-06 20:38:34 +01:00 committed by Patric Stout
parent f2a93dba0d
commit 2da07f7615
2 changed files with 94 additions and 76 deletions

View File

@ -664,19 +664,90 @@ void VideoDriver_SDL::Stop()
}
}
void VideoDriver_SDL::MainLoop()
void VideoDriver_SDL::LoopOnce()
{
uint32 cur_ticks = SDL_GetTicks();
uint32 last_cur_ticks = cur_ticks;
uint32 next_tick = cur_ticks + MILLISECONDS_PER_TICK;
uint32 mod;
int numkeys;
const Uint8 *keys;
uint32 prev_cur_ticks = cur_ticks; // to check for wrapping
InteractiveRandom(); // randomness
while (PollEvent() == -1) {}
if (_exit_game) return;
mod = SDL_GetModState();
keys = SDL_GetKeyboardState(&numkeys);
#if defined(_DEBUG)
if (_shift_pressed)
#else
/* Speedup when pressing tab, except when using ALT+TAB
* to switch to another application */
if (keys[SDL_SCANCODE_TAB] && (mod & KMOD_ALT) == 0)
#endif /* defined(_DEBUG) */
{
if (!_networking && _game_mode != GM_MENU) _fast_forward |= 2;
} else if (_fast_forward & 2) {
_fast_forward = 0;
}
cur_ticks = SDL_GetTicks();
if (SDL_TICKS_PASSED(cur_ticks, next_tick) || (_fast_forward && !_pause_mode) || cur_ticks < prev_cur_ticks) {
_realtime_tick += cur_ticks - last_cur_ticks;
last_cur_ticks = cur_ticks;
next_tick = cur_ticks + MILLISECONDS_PER_TICK;
bool old_ctrl_pressed = _ctrl_pressed;
_ctrl_pressed = !!(mod & KMOD_CTRL);
_shift_pressed = !!(mod & KMOD_SHIFT);
/* determine which directional keys are down */
_dirkeys =
(keys[SDL_SCANCODE_LEFT] ? 1 : 0) |
(keys[SDL_SCANCODE_UP] ? 2 : 0) |
(keys[SDL_SCANCODE_RIGHT] ? 4 : 0) |
(keys[SDL_SCANCODE_DOWN] ? 8 : 0);
if (old_ctrl_pressed != _ctrl_pressed) HandleCtrlChanged();
/* The gameloop is the part that can run asynchronously. The rest
* except sleeping can't. */
if (_draw_mutex != nullptr) draw_lock.unlock();
GameLoop();
if (_draw_mutex != nullptr) draw_lock.lock();
UpdateWindows();
_local_palette = _cur_palette;
} else {
/* Release the thread while sleeping */
if (_draw_mutex != nullptr) draw_lock.unlock();
CSleep(1);
if (_draw_mutex != nullptr) draw_lock.lock();
NetworkDrawChatMessage();
DrawMouseCursor();
}
/* End of the critical part. */
if (_draw_mutex != nullptr && !HasModalProgress()) {
_draw_signal->notify_one();
} else {
/* Oh, we didn't have threads, then just draw unthreaded */
CheckPaletteAnim();
DrawSurfaceToScreen();
}
}
void VideoDriver_SDL::MainLoop()
{
cur_ticks = SDL_GetTicks();
last_cur_ticks = cur_ticks;
next_tick = cur_ticks + MILLISECONDS_PER_TICK;
CheckPaletteAnim();
std::thread draw_thread;
std::unique_lock<std::recursive_mutex> draw_lock;
if (_draw_threaded) {
/* Initialise the mutex first, because that's the thing we *need*
* directly in the newly created thread. */
@ -707,78 +778,16 @@ void VideoDriver_SDL::MainLoop()
DEBUG(driver, 1, "SDL2: using %sthreads", _draw_threaded ? "" : "no ");
for (;;) {
uint32 prev_cur_ticks = cur_ticks; // to check for wrapping
InteractiveRandom(); // randomness
while (PollEvent() == -1) {}
if (_exit_game) break;
mod = SDL_GetModState();
keys = SDL_GetKeyboardState(&numkeys);
#if defined(_DEBUG)
if (_shift_pressed)
#else
/* Speedup when pressing tab, except when using ALT+TAB
* to switch to another application */
if (keys[SDL_SCANCODE_TAB] && (mod & KMOD_ALT) == 0)
#endif /* defined(_DEBUG) */
{
if (!_networking && _game_mode != GM_MENU) _fast_forward |= 2;
} else if (_fast_forward & 2) {
_fast_forward = 0;
}
cur_ticks = SDL_GetTicks();
if (SDL_TICKS_PASSED(cur_ticks, next_tick) || (_fast_forward && !_pause_mode) || cur_ticks < prev_cur_ticks) {
_realtime_tick += cur_ticks - last_cur_ticks;
last_cur_ticks = cur_ticks;
next_tick = cur_ticks + MILLISECONDS_PER_TICK;
bool old_ctrl_pressed = _ctrl_pressed;
_ctrl_pressed = !!(mod & KMOD_CTRL);
_shift_pressed = !!(mod & KMOD_SHIFT);
/* determine which directional keys are down */
_dirkeys =
(keys[SDL_SCANCODE_LEFT] ? 1 : 0) |
(keys[SDL_SCANCODE_UP] ? 2 : 0) |
(keys[SDL_SCANCODE_RIGHT] ? 4 : 0) |
(keys[SDL_SCANCODE_DOWN] ? 8 : 0);
if (old_ctrl_pressed != _ctrl_pressed) HandleCtrlChanged();
/* The gameloop is the part that can run asynchronously. The rest
* except sleeping can't. */
if (_draw_mutex != nullptr) draw_lock.unlock();
GameLoop();
if (_draw_mutex != nullptr) draw_lock.lock();
UpdateWindows();
_local_palette = _cur_palette;
} else {
/* Release the thread while sleeping */
if (_draw_mutex != nullptr) draw_lock.unlock();
CSleep(1);
if (_draw_mutex != nullptr) draw_lock.lock();
NetworkDrawChatMessage();
DrawMouseCursor();
}
/* End of the critical part. */
if (_draw_mutex != nullptr && !HasModalProgress()) {
_draw_signal->notify_one();
} else {
/* Oh, we didn't have threads, then just draw unthreaded */
CheckPaletteAnim();
DrawSurfaceToScreen();
}
while (!_exit_game) {
LoopOnce();
}
MainLoopCleanup();
#endif
}
void VideoDriver_SDL::MainLoopCleanup()
{
if (_draw_mutex != nullptr) {
_draw_continue = false;
/* Sending signal if there is no thread blocked

View File

@ -42,12 +42,21 @@ public:
const char *GetName() const override { return "sdl"; }
private:
int PollEvent();
void LoopOnce();
void MainLoopCleanup();
bool CreateMainSurface(uint w, uint h, bool resize);
/**
* This is true to indicate that keyboard input is in text input mode, and SDL_TEXTINPUT events are enabled.
*/
bool edit_box_focused;
uint32 cur_ticks;
uint32 last_cur_ticks;
uint32 next_tick;
std::thread draw_thread;
std::unique_lock<std::recursive_mutex> draw_lock;
};
/** Factory for the SDL video driver. */