Function UpdateWindows

src/window.cpp:3127–3172

* Update the continuously changing contents of the windows, such as the viewports */

 * Update the continuously changing contents of the windows, such as the viewports
 */
void UpdateWindows()
{
	static auto last_time = std::chrono::steady_clock::now();
	auto now = std::chrono::steady_clock::now();
	auto delta_ms = std::chrono::duration_cast<std::chrono::milliseconds>(now - last_time);

	if (delta_ms.count() == 0) return;

	last_time = now;

	PerformanceMeasurer framerate(PFE_DRAWING);
	PerformanceAccumulator::Reset(PFE_DRAWWORLD);

	ProcessPendingPerformanceMeasurements();

	TimerManager<TimerWindow>::Elapsed(delta_ms);
	CallWindowRealtimeTickEvent(delta_ms.count());

	/* Process invalidations before anything else. */
	for (Window *w : Window::Iterate()) {
		w->ProcessScheduledResize();
		w->ProcessScheduledInvalidations();
		w->ProcessHighlightedInvalidations();
	}

	/* Skip the actual drawing on dedicated servers without screen.
	 * But still empty the invalidation queues above. */
	if (_network_dedicated) return;

	DrawDirtyBlocks();

	for (Window *w : Window::Iterate()) {
		/* Update viewport only if window is not shaded. */
		if (w->viewport != nullptr && !w->IsShaded()) UpdateViewportPosition(w, delta_ms.count());
	}
	NetworkDrawChatMessage();
	/* Redraw mouse cursor in case it was hidden */
	DrawMouseCursor();

	if (_newgrf_debug_sprite_picker.mode == SPM_REDRAW) {
		/* We are done with the last draw-frame, so we know what sprites we
		 * clicked on. Reset the picker mode and invalidate the window. */
		_newgrf_debug_sprite_picker.mode = SPM_NONE;
		InvalidateWindowData(WC_SPRITE_ALIGNER, 0, 1);
	}
}

/**
 * Mark window as dirty (in need of repainting)