Feature: configurable refresh-rate and change default to 60fps

Most modern games run on 60 fps, and for good reason. This gives
a much smoother experiences.

As some people have monitors that can do 144Hz or even 240Hz, allow
people to configure the refresh rate. Of course, the higher you
set the value, the more time the game spends on drawing pixels
instead of simulating the game, which has an effect on simulation
speed.

The simulation will still always run at 33.33 fps, and is not
influences by this setting.

7 files changed, 37 insertions, 25 deletions

diff --git a/src/video/allegro_v.cpp b/src/video/allegro_v.cpp
index 800cce40c..29db2f1da 100644
--- a/src/video/allegro_v.cpp
+++ b/src/video/allegro_v.cpp
@@ -485,20 +485,20 @@ void VideoDriver_Allegro::MainLoop()
 
 		if (cur_ticks >= next_game_tick || (_fast_forward && !_pause_mode)) {
 			if (_fast_forward && !_pause_mode) {
-				next_game_tick = cur_ticks + std::chrono::milliseconds(MILLISECONDS_PER_TICK);
+				next_game_tick = cur_ticks + this->GetGameInterval();
 			} else {
-				next_game_tick += std::chrono::milliseconds(MILLISECONDS_PER_TICK);
+				next_game_tick += this->GetGameInterval();
 				/* Avoid next_game_tick getting behind more and more if it cannot keep up. */
-				if (next_game_tick < cur_ticks - std::chrono::milliseconds(ALLOWED_DRIFT * MILLISECONDS_PER_TICK)) next_game_tick = cur_ticks;
+				if (next_game_tick < cur_ticks - ALLOWED_DRIFT * this->GetGameInterval()) next_game_tick = cur_ticks;
 			}
 
 			GameLoop();
 		}
 
 		if (cur_ticks >= next_draw_tick) {
-			next_draw_tick += std::chrono::milliseconds(MILLISECONDS_PER_TICK);
+			next_draw_tick += this->GetDrawInterval();
 			/* Avoid next_draw_tick getting behind more and more if it cannot keep up. */
-			if (next_draw_tick < cur_ticks - std::chrono::microseconds(ALLOWED_DRIFT * MILLISECONDS_PER_TICK)) next_draw_tick = cur_ticks;
+			if (next_draw_tick < cur_ticks - ALLOWED_DRIFT * this->GetDrawInterval()) next_draw_tick = cur_ticks;
 
 			bool old_ctrl_pressed = _ctrl_pressed;
 
diff --git a/src/video/cocoa/cocoa_v.mm b/src/video/cocoa/cocoa_v.mm
index 7c8981f61..31bad36dc 100644
--- a/src/video/cocoa/cocoa_v.mm
+++ b/src/video/cocoa/cocoa_v.mm
@@ -675,20 +675,20 @@ void VideoDriver_Cocoa::GameLoop()
 
 			if (cur_ticks >= next_game_tick || (_fast_forward && !_pause_mode)) {
 				if (_fast_forward && !_pause_mode) {
-					next_game_tick = cur_ticks + std::chrono::milliseconds(MILLISECONDS_PER_TICK);
+					next_game_tick = cur_ticks + this->GetGameInterval();
 				} else {
-					next_game_tick += std::chrono::milliseconds(MILLISECONDS_PER_TICK);
+					next_game_tick += this->GetGameInterval();
 					/* Avoid next_game_tick getting behind more and more if it cannot keep up. */
-					if (next_game_tick < cur_ticks - std::chrono::milliseconds(ALLOWED_DRIFT * MILLISECONDS_PER_TICK)) next_game_tick = cur_ticks;
+					if (next_game_tick < cur_ticks - ALLOWED_DRIFT * this->GetGameInterval()) next_game_tick = cur_ticks;
 				}
 
 				::GameLoop();
 			}
 
 			if (cur_ticks >= next_draw_tick) {
-				next_draw_tick += std::chrono::milliseconds(MILLISECONDS_PER_TICK);
+				next_draw_tick += this->GetDrawInterval();
 				/* Avoid next_draw_tick getting behind more and more if it cannot keep up. */
-				if (next_draw_tick < cur_ticks - std::chrono::microseconds(ALLOWED_DRIFT * MILLISECONDS_PER_TICK)) next_draw_tick = cur_ticks;
+				if (next_draw_tick < cur_ticks - ALLOWED_DRIFT * this->GetDrawInterval()) next_draw_tick = cur_ticks;
 
 				bool old_ctrl_pressed = _ctrl_pressed;
 
diff --git a/src/video/dedicated_v.cpp b/src/video/dedicated_v.cpp
index 845b0bf8c..53351458a 100644
--- a/src/video/dedicated_v.cpp
+++ b/src/video/dedicated_v.cpp
@@ -294,11 +294,11 @@ void VideoDriver_Dedicated::MainLoop()
 
 		if (cur_ticks >= next_game_tick || _ddc_fastforward) {
 			if (_ddc_fastforward) {
-				next_game_tick = cur_ticks + std::chrono::milliseconds(MILLISECONDS_PER_TICK);
+				next_game_tick = cur_ticks + this->GetGameInterval();
 			} else {
-				next_game_tick += std::chrono::milliseconds(MILLISECONDS_PER_TICK);
+				next_game_tick += this->GetGameInterval();
 				/* Avoid next_game_tick getting behind more and more if it cannot keep up. */
-				if (next_game_tick < cur_ticks - std::chrono::milliseconds(ALLOWED_DRIFT * MILLISECONDS_PER_TICK)) next_game_tick = cur_ticks;
+				if (next_game_tick < cur_ticks - ALLOWED_DRIFT * this->GetGameInterval()) next_game_tick = cur_ticks;
 			}
 
 			GameLoop();
diff --git a/src/video/sdl2_v.cpp b/src/video/sdl2_v.cpp
index 7c04b8743..4170a953c 100644
--- a/src/video/sdl2_v.cpp
+++ b/src/video/sdl2_v.cpp
@@ -793,9 +793,9 @@ void VideoDriver_SDL::LoopOnce()
 	}
 
 	if (cur_ticks >= next_draw_tick) {
-		next_draw_tick += std::chrono::milliseconds(MILLISECONDS_PER_TICK);
+		next_draw_tick += this->GetDrawInterval();
 		/* Avoid next_draw_tick getting behind more and more if it cannot keep up. */
-		if (next_draw_tick < cur_ticks - std::chrono::microseconds(ALLOWED_DRIFT * MILLISECONDS_PER_TICK)) next_draw_tick = cur_ticks;
+		if (next_draw_tick < cur_ticks - ALLOWED_DRIFT * this->GetDrawInterval()) next_draw_tick = cur_ticks;
 
 		bool old_ctrl_pressed = _ctrl_pressed;
 
diff --git a/src/video/sdl_v.cpp b/src/video/sdl_v.cpp
index 9f28b641c..0a603f979 100644
--- a/src/video/sdl_v.cpp
+++ b/src/video/sdl_v.cpp
@@ -731,11 +731,11 @@ void VideoDriver_SDL::MainLoop()
 
 		if (cur_ticks >= next_game_tick || (_fast_forward && !_pause_mode)) {
 			if (_fast_forward && !_pause_mode) {
-				next_game_tick = cur_ticks + std::chrono::milliseconds(MILLISECONDS_PER_TICK);
+				next_game_tick = cur_ticks + this->GetGameInterval();
 			} else {
-				next_game_tick += std::chrono::milliseconds(MILLISECONDS_PER_TICK);
+				next_game_tick += this->GetGameInterval();
 				/* Avoid next_game_tick getting behind more and more if it cannot keep up. */
-				if (next_game_tick < cur_ticks - std::chrono::milliseconds(ALLOWED_DRIFT * MILLISECONDS_PER_TICK)) next_game_tick = cur_ticks;
+				if (next_game_tick < cur_ticks - ALLOWED_DRIFT * this->GetGameInterval()) next_game_tick = cur_ticks;
 			}
 
 			/* The gameloop is the part that can run asynchronously. The rest
@@ -746,9 +746,9 @@ void VideoDriver_SDL::MainLoop()
 		}
 
 		if (cur_ticks >= next_draw_tick) {
-			next_draw_tick += std::chrono::milliseconds(MILLISECONDS_PER_TICK);
+			next_draw_tick += this->GetDrawInterval();
 			/* Avoid next_draw_tick getting behind more and more if it cannot keep up. */
-			if (next_draw_tick < cur_ticks - std::chrono::microseconds(ALLOWED_DRIFT * MILLISECONDS_PER_TICK)) next_draw_tick = cur_ticks;
+			if (next_draw_tick < cur_ticks - ALLOWED_DRIFT * this->GetDrawInterval()) next_draw_tick = cur_ticks;
 
 			bool old_ctrl_pressed = _ctrl_pressed;
 
diff --git a/src/video/video_driver.hpp b/src/video/video_driver.hpp
index 94803db22..732050c76 100644
--- a/src/video/video_driver.hpp
+++ b/src/video/video_driver.hpp
@@ -13,7 +13,9 @@
 #include "../driver.h"
 #include "../core/geometry_type.hpp"
 #include "../core/math_func.hpp"
+#include "../settings_type.h"
 #include "../zoom_type.h"
+#include <chrono>
 #include <vector>
 
 extern std::string _ini_videodriver;
@@ -153,6 +155,16 @@ protected:
 			_cur_resolution.height = ClampU(res.height * 3 / 4, DEFAULT_WINDOW_HEIGHT, UINT16_MAX / 2);
 		}
 	}
+
+	std::chrono::steady_clock::duration GetGameInterval()
+	{
+		return std::chrono::milliseconds(MILLISECONDS_PER_TICK);
+	}
+
+	std::chrono::steady_clock::duration GetDrawInterval()
+	{
+		return std::chrono::microseconds(1000000 / _settings_client.gui.refresh_rate);
+	}
 };
 
 #endif /* VIDEO_VIDEO_DRIVER_HPP */
diff --git a/src/video/win32_v.cpp b/src/video/win32_v.cpp
index 42fcf3f4b..a15071178 100644
--- a/src/video/win32_v.cpp
+++ b/src/video/win32_v.cpp
@@ -1208,11 +1208,11 @@ void VideoDriver_Win32::MainLoop()
 
 		if (cur_ticks >= next_game_tick || (_fast_forward && !_pause_mode)) {
 			if (_fast_forward && !_pause_mode) {
-				next_game_tick = cur_ticks + std::chrono::milliseconds(MILLISECONDS_PER_TICK);
+				next_game_tick = cur_ticks + this->GetGameInterval();
 			} else {
-				next_game_tick += std::chrono::milliseconds(MILLISECONDS_PER_TICK);
+				next_game_tick += this->GetGameInterval();
 				/* Avoid next_game_tick getting behind more and more if it cannot keep up. */
-				if (next_game_tick < cur_ticks - std::chrono::milliseconds(ALLOWED_DRIFT * MILLISECONDS_PER_TICK)) next_game_tick = cur_ticks;
+				if (next_game_tick < cur_ticks - ALLOWED_DRIFT * this->GetGameInterval()) next_game_tick = cur_ticks;
 			}
 
 			/* Flush GDI buffer to ensure we don't conflict with the drawing thread. */
@@ -1226,9 +1226,9 @@ void VideoDriver_Win32::MainLoop()
 		}
 
 		if (cur_ticks >= next_draw_tick) {
-			next_draw_tick += std::chrono::milliseconds(MILLISECONDS_PER_TICK);
+			next_draw_tick += this->GetDrawInterval();
 			/* Avoid next_draw_tick getting behind more and more if it cannot keep up. */
-			if (next_draw_tick < cur_ticks - std::chrono::microseconds(ALLOWED_DRIFT * MILLISECONDS_PER_TICK)) next_draw_tick = cur_ticks;
+			if (next_draw_tick < cur_ticks - ALLOWED_DRIFT * this->GetDrawInterval()) next_draw_tick = cur_ticks;
 
 			bool old_ctrl_pressed = _ctrl_pressed;