6 files changed, 13 insertions, 10 deletions
diff --git a/src/gfx_type.h b/src/gfx_type.h
index 8c4bf918f..b1ee21172 100644
--- a/src/gfx_type.h
+++ b/src/gfx_type.h
@@ -259,4 +259,7 @@ enum SpriteType {
 	ST_INVALID  = 4,      ///< Pseudosprite or other unusable sprite, used only internally
 };
 
+/** The number of milliseconds per game tick. */
+static const uint MILLISECONDS_PER_TICK = 30;
+
 #endif /* GFX_TYPE_H */
diff --git a/src/video/allegro_v.cpp b/src/video/allegro_v.cpp
index c4a8341c9..bcec85333 100644
--- a/src/video/allegro_v.cpp
+++ b/src/video/allegro_v.cpp
@@ -474,7 +474,7 @@ void VideoDriver_Allegro::MainLoop()
 {
 	uint32 cur_ticks = GetTime();
 	uint32 last_cur_ticks = cur_ticks;
-	uint32 next_tick = cur_ticks + 30;
+	uint32 next_tick = cur_ticks + MILLISECONDS_PER_TICK;
 	uint32 pal_tick = 0;
 
 	for (;;) {
@@ -501,7 +501,7 @@ void VideoDriver_Allegro::MainLoop()
 		if (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 + 30;
+			next_tick = cur_ticks + MILLISECONDS_PER_TICK;
 
 			bool old_ctrl_pressed = _ctrl_pressed;
 
diff --git a/src/video/cocoa/event.mm b/src/video/cocoa/event.mm
index bf643955e..7d7fa4cf8 100644
--- a/src/video/cocoa/event.mm
+++ b/src/video/cocoa/event.mm
@@ -606,7 +606,7 @@ void QZ_GameLoop()
 {
 	uint32 cur_ticks = GetTick();
 	uint32 last_cur_ticks = cur_ticks;
-	uint32 next_tick = cur_ticks + 30;
+	uint32 next_tick = cur_ticks + MILLISECONDS_PER_TICK;
 	uint32 pal_tick = 0;
 
 #ifdef _DEBUG
@@ -655,7 +655,7 @@ void QZ_GameLoop()
 		if (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 + 30;
+			next_tick = cur_ticks + MILLISECONDS_PER_TICK;
 
 			bool old_ctrl_pressed = _ctrl_pressed;
 
diff --git a/src/video/dedicated_v.cpp b/src/video/dedicated_v.cpp
index 2e35f4678..f2ebd0f00 100644
--- a/src/video/dedicated_v.cpp
+++ b/src/video/dedicated_v.cpp
@@ -256,7 +256,7 @@ static void DedicatedHandleKeyInput()
 void VideoDriver_Dedicated::MainLoop()
 {
 	uint32 cur_ticks = GetTime();
-	uint32 next_tick = cur_ticks + 30;
+	uint32 next_tick = cur_ticks + MILLISECONDS_PER_TICK;
 
 	/* Signal handlers */
 #if defined(UNIX) || defined(PSP)
@@ -305,7 +305,7 @@ void VideoDriver_Dedicated::MainLoop()
 		cur_ticks = GetTime();
 		_realtime_tick += cur_ticks - prev_cur_ticks;
 		if (cur_ticks >= next_tick || cur_ticks < prev_cur_ticks || _ddc_fastforward) {
-			next_tick = cur_ticks + 30;
+			next_tick = cur_ticks + MILLISECONDS_PER_TICK;
 
 			GameLoop();
 			UpdateWindows();
diff --git a/src/video/sdl_v.cpp b/src/video/sdl_v.cpp
index 9e0a38fa9..f16ca69d7 100644
--- a/src/video/sdl_v.cpp
+++ b/src/video/sdl_v.cpp
@@ -497,7 +497,7 @@ void VideoDriver_SDL::MainLoop()
 {
 	uint32 cur_ticks = SDL_CALL SDL_GetTicks();
 	uint32 last_cur_ticks = cur_ticks;
-	uint32 next_tick = cur_ticks + 30;
+	uint32 next_tick = cur_ticks + MILLISECONDS_PER_TICK;
 	uint32 pal_tick = 0;
 	uint32 mod;
 	int numkeys;
@@ -554,7 +554,7 @@ void VideoDriver_SDL::MainLoop()
 		if (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 + 30;
+			next_tick = cur_ticks + MILLISECONDS_PER_TICK;
 
 			bool old_ctrl_pressed = _ctrl_pressed;
 
diff --git a/src/video/win32_v.cpp b/src/video/win32_v.cpp
index 755d6f17a..f411dcdce 100644
--- a/src/video/win32_v.cpp
+++ b/src/video/win32_v.cpp
@@ -832,7 +832,7 @@ void VideoDriver_Win32::MainLoop()
 	MSG mesg;
 	uint32 cur_ticks = GetTickCount();
 	uint32 last_cur_ticks = cur_ticks;
-	uint32 next_tick = cur_ticks + 30;
+	uint32 next_tick = cur_ticks + MILLISECONDS_PER_TICK;
 
 	_wnd.running = true;
 
@@ -862,7 +862,7 @@ void VideoDriver_Win32::MainLoop()
 		if (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 + 30;
+			next_tick = cur_ticks + MILLISECONDS_PER_TICK;
 
 			bool old_ctrl_pressed = _ctrl_pressed;