From 4d0da8f6acbb7b913e5870ededae0dc1f0deacca Mon Sep 17 00:00:00 2001
From: ALONSO Laurent <laurent.alonso@inria.fr>
Date: Fri, 8 Oct 2021 11:26:35 +0200
Subject: [PATCH] game: try to make Blades of Exile less CPU hungry...

---
 src/game/boe.main.cpp | 42 ++++++++++++++++++++++++++++--------------
 src/game/boe.main.hpp |  4 +---
 2 files changed, 29 insertions(+), 17 deletions(-)

diff --git a/src/game/boe.main.cpp b/src/game/boe.main.cpp
index b54f3132..dad35d2f 100644
--- a/src/game/boe.main.cpp
+++ b/src/game/boe.main.cpp
@@ -267,10 +267,12 @@ void handle_events() {
 	cFramerateLimiter fps_limiter;
 
 	while(!All_Done) {
+		bool need_redraw=false;
 #ifdef __APPLE__
 		if (menuChoiceId>=0) {
 			eMenuChoice aMenuChoice=menuChoice;
 			menuChoice=eMenuChoice::MENU_CHOICE_NONE;
+			need_redraw=true;
 			switch(aMenuChoice) {
 				case eMenuChoice::MENU_CHOICE_GENERIC:
 					handle_menu_choice(eMenu(menuChoiceId));
@@ -282,19 +284,27 @@ void handle_events() {
 					handle_monster_info_menu(menuChoiceId);
 					break;
 				case eMenuChoice::MENU_CHOICE_NONE:
+					need_redraw=false;
 					break;
 			}
 			menuChoiceId=-1;
 		}
 #endif
-		while(mainPtr.pollEvent(currentEvent)) handle_one_event(currentEvent);
+		while(mainPtr.pollEvent(currentEvent)) {
+			need_redraw=true;
+			handle_one_event(currentEvent);
+		}
 
 		// It would be nice to have minimap inside the main game window (we have lots of screen space in fullscreen mode).
 		// Alternatively, minimap could live on its own thread.
 		// But for now we just handle events from both windows on this thread.
-		while(map_visible && mini_map.pollEvent(currentEvent)) handle_one_minimap_event(currentEvent);
+		while(map_visible && mini_map.pollEvent(currentEvent)) {
+			need_redraw = true;
+			handle_one_minimap_event(currentEvent);
+		}
 
 		if(changed_display_mode) {
+			need_redraw = true;
 			changed_display_mode = false;
 			adjust_window_mode();
 			init_mini_map();
@@ -305,10 +315,12 @@ void handle_events() {
 
 		// Ideally this call should update all of the things that are happening in the world current tick.
 		// NOTE that update does not mean draw.
-		update_everything();
+		if (update_everything())
+			need_redraw=true;
 
 		// Ideally, this should be the only draw call that is done in a cycle.
-		redraw_everything();
+		if (need_redraw)
+			redraw_everything();
 
 		// Prevent the loop from executing too fast.
 		fps_limiter.frame_finished();
@@ -407,30 +419,32 @@ void handle_one_minimap_event(const sf::Event& event) {
 	}
 }
 
-void update_terrain_animation() {
+static bool update_terrain_animation() {
 	static const long fortyTicks = time_in_ticks(40).asMilliseconds();
 
-	if(overall_mode == MODE_STARTUP) return;
-	if(!get_bool_pref("DrawTerrainAnimation", true)) return;
-	if(animTimer.getElapsedTime().asMilliseconds() < fortyTicks) return;
+	if(overall_mode == MODE_STARTUP) return false;
+	if(!get_bool_pref("DrawTerrainAnimation", true)) return false;
+	if(animTimer.getElapsedTime().asMilliseconds() < fortyTicks) return false;
 
 	anim_ticks++;
 	animTimer.restart();
+	return true;
 }
 
-void update_startup_animation() {
+static bool update_startup_animation() {
 	static const long twentyTicks = time_in_ticks(20).asMilliseconds();
 
-	if(overall_mode != MODE_STARTUP) return;
-	if(animTimer.getElapsedTime().asMilliseconds() < twentyTicks) return;
+	if(overall_mode != MODE_STARTUP) return false;
+	if(animTimer.getElapsedTime().asMilliseconds() < twentyTicks) return false;
 
 	draw_startup_anim(true);
 	animTimer.restart();
+	return true;
 }
 
-void update_everything() {
-	update_terrain_animation();
-	update_startup_animation();
+bool update_everything() {
+	return update_terrain_animation() ||
+		update_startup_animation();
 }
 
 void redraw_everything() {
diff --git a/src/game/boe.main.hpp b/src/game/boe.main.hpp
index a99130cf..c985b2b3 100644
--- a/src/game/boe.main.hpp
+++ b/src/game/boe.main.hpp
@@ -6,7 +6,7 @@ extern eMenuChoice menuChoice;
 extern short menuChoiceId;
 #endif
 int main(int argc, char* argv[]);
-void update_everything();
+bool update_everything();
 void redraw_everything();
 void Mouse_Pressed(const sf::Event&);
 void close_program();
@@ -19,8 +19,6 @@ bool handle_startup_press(location the_point);
 void handle_splash_events();
 void show_logo();
 void plop_fancy_startup();
-void update_terrain_animation();
-void update_startup_animation();
 void handle_events();
 void handle_one_event(const sf::Event&);
 void handle_one_minimap_event(const sf::Event &);