Fix d437445c: also use std::chrono for the GRFFileScanner modal window

For some reason I only converted one of the two modal windows we
have, and completely forgot the other.

While at it, synchronize the way those two modal windows work
in terms of "next_update".

2 files changed, 12 insertions, 12 deletions

diff --git a/src/genworld_gui.cpp b/src/genworld_gui.cpp
index 7ef993733..bf4d327a7 100644
--- a/src/genworld_gui.cpp
+++ b/src/genworld_gui.cpp
@@ -1188,7 +1188,7 @@ struct GenWorldStatus {
 	StringID cls;
 	uint current;
 	uint total;
-	std::chrono::steady_clock::time_point timer;
+	std::chrono::steady_clock::time_point next_update;
 };
 
 static GenWorldStatus _gws;
@@ -1290,11 +1290,11 @@ struct GenerateProgressWindow : public Window {
  */
 void PrepareGenerateWorldProgress()
 {
-	_gws.cls     = STR_GENERATION_WORLD_GENERATION;
+	_gws.cls = STR_GENERATION_WORLD_GENERATION;
 	_gws.current = 0;
-	_gws.total   = 0;
+	_gws.total = 0;
 	_gws.percent = 0;
-	_gws.timer   = std::chrono::steady_clock::now() - std::chrono::milliseconds(MODAL_PROGRESS_REDRAW_TIMEOUT * 2); // Ensure we draw on first update
+	_gws.next_update = std::chrono::steady_clock::now();
 }
 
 /**
@@ -1329,7 +1329,8 @@ static void _SetGeneratingWorldProgress(GenWorldProgress cls, uint progress, uin
 	}
 
 	/* Don't update the screen too often. So update it once in every once in a while... */
-	if (!_network_dedicated && std::chrono::steady_clock::now() - _gws.timer < std::chrono::milliseconds(MODAL_PROGRESS_REDRAW_TIMEOUT)) return;
+	if (!_network_dedicated && std::chrono::steady_clock::now() < _gws.next_update) return;
+	_gws.next_update = std::chrono::steady_clock::now() + std::chrono::milliseconds(MODAL_PROGRESS_REDRAW_TIMEOUT);
 
 	/* Percentage is about the number of completed tasks, so 'current - 1' */
 	_gws.percent = percent_table[cls] + (percent_table[cls + 1] - percent_table[cls]) * (_gws.current == 0 ? 0 : _gws.current - 1) / _gws.total;
@@ -1364,8 +1365,6 @@ static void _SetGeneratingWorldProgress(GenWorldProgress cls, uint progress, uin
 	_modal_progress_paint_mutex.lock();
 	_modal_progress_work_mutex.lock();
 	_modal_progress_paint_mutex.unlock();
-
-	_gws.timer = std::chrono::steady_clock::now();
 }
 
 /**
diff --git a/src/newgrf_config.cpp b/src/newgrf_config.cpp
index cd95a4b8a..e56f878bd 100644
--- a/src/newgrf_config.cpp
+++ b/src/newgrf_config.cpp
@@ -578,12 +578,13 @@ compatible_grf:
 
 /** Helper for scanning for files with GRF as extension */
 class GRFFileScanner : FileScanner {
-	uint next_update; ///< The next (realtime tick) we do update the screen.
+	std::chrono::steady_clock::time_point next_update; ///< The next moment we do update the screen.
 	uint num_scanned; ///< The number of GRFs we have scanned.
 
 public:
-	GRFFileScanner() : next_update(_realtime_tick), num_scanned(0)
+	GRFFileScanner() : num_scanned(0)
 	{
+		this->next_update = std::chrono::steady_clock::now();
 	}
 
 	bool AddFile(const std::string &filename, size_t basepath_length, const std::string &tar_filename) override;
@@ -634,7 +635,9 @@ bool GRFFileScanner::AddFile(const std::string &filename, size_t basepath_length
 	}
 
 	this->num_scanned++;
-	if (this->next_update <= _realtime_tick) {
+	if (std::chrono::steady_clock::now() >= this->next_update) {
+		this->next_update = std::chrono::steady_clock::now() + std::chrono::milliseconds(MODAL_PROGRESS_REDRAW_TIMEOUT);
+
 		_modal_progress_work_mutex.unlock();
 		_modal_progress_paint_mutex.lock();
 
@@ -645,8 +648,6 @@ bool GRFFileScanner::AddFile(const std::string &filename, size_t basepath_length
 
 		_modal_progress_work_mutex.lock();
 		_modal_progress_paint_mutex.unlock();
-
-		this->next_update = _realtime_tick + MODAL_PROGRESS_REDRAW_TIMEOUT;
 	}
 
 	if (!added) {