Fix game not allowing to catch up if rendering is slow.

Refactored game_update to use the given parameters from context.

src/openrct2/Context.cpp

@@ -25,6 +25,7 @@
 #include "core/FileScanner.h"
 #include "core/FileStream.hpp"
 #include "core/Guard.hpp"
+#include "core/Math.hpp"
 #include "core/MemoryStream.h"
 #include "core/Path.hpp"
 #include "core/String.hpp"
@@ -361,7 +362,7 @@ namespace OpenRCT2
                     }
                     network_begin_server(gNetworkStartPort, gNetworkStartAddress);
                 }
- #endif // DISABLE_NETWORK
+#endif // DISABLE_NETWORK
                 break;
             }
             case STARTUP_ACTION_EDIT:
@@ -442,23 +443,18 @@ namespace OpenRCT2
             }
 
             uint32 elapsed = currentTick - _lastTick;
-            if (elapsed > UPDATE_TIME_MS)
-            {
-                elapsed = UPDATE_TIME_MS;
-            }
-
             _lastTick = currentTick;
-            _accumulator += elapsed;
+            _accumulator = Math::Min(_accumulator + elapsed, (uint32)GAME_UPDATE_MAX_THRESHOLD);
 
             _uiContext->ProcessMessages();
 
-            if (_accumulator < UPDATE_TIME_MS)
+            if (_accumulator < GAME_UPDATE_TIME_MS)
             {
-                platform_sleep(UPDATE_TIME_MS - _accumulator - 1);
+                platform_sleep(GAME_UPDATE_TIME_MS - _accumulator - 1);
                 return;
             }
 
-            _accumulator -= UPDATE_TIME_MS;
+            _accumulator -= GAME_UPDATE_TIME_MS;
 
             Update();
             if (!_isWindowMinimised && !gOpenRCT2Headless)
@@ -480,17 +476,13 @@ namespace OpenRCT2
             }
 
             uint32 elapsed = currentTick - _lastTick;
-            if (elapsed > UPDATE_TIME_MS)
-            {
-                elapsed = UPDATE_TIME_MS;
-            }
 
             _lastTick = currentTick;
-            _accumulator += elapsed;
+            _accumulator = Math::Min(_accumulator + elapsed, (uint32)GAME_UPDATE_MAX_THRESHOLD);
 
             _uiContext->ProcessMessages();
 
-            while (_accumulator >= UPDATE_TIME_MS)
+            while (_accumulator >= GAME_UPDATE_TIME_MS)
             {
                 // Get the original position of each sprite
                 if(draw)
@@ -498,7 +490,7 @@ namespace OpenRCT2
 
                 Update();
 
-                _accumulator -= UPDATE_TIME_MS;
+                _accumulator -= GAME_UPDATE_TIME_MS;
 
                 // Get the next position of each sprite
                 if(draw)
@@ -507,7 +499,7 @@ namespace OpenRCT2
 
             if (draw)
             {
-                const float alpha = (float)_accumulator / UPDATE_TIME_MS;
+                const float alpha = (float)_accumulator / GAME_UPDATE_TIME_MS;
                 sprite_position_tween_all(alpha);
 
                 drawing_engine_draw();

src/openrct2/Context.h

@@ -103,15 +103,23 @@ namespace OpenRCT2
     IContext * CreateContext();
     IContext * CreateContext(IPlatformEnvironment * env, Audio::IAudioContext * audioContext, Ui::IUiContext * uiContext);
     IContext * GetContext();
-
-    // The game update inverval in milliseconds, (1000 / 40fps) = 25ms
-    constexpr uint32 UPDATE_TIME_MS = 25;
-    // The number of logical update / ticks per second.
-    constexpr uint32 UPDATE_FPS = 40;
 }
 
 #endif // __cplusplus
 
+enum
+{
+    // The game update inverval in milliseconds, (1000 / 40fps) = 25ms
+    GAME_UPDATE_TIME_MS = 25,
+    // The number of logical update / ticks per second.
+    GAME_UPDATE_FPS = 40,
+    // The maximum amount of updates in case rendering is slower
+    GAME_MAX_UPDATES = 4,
+    // The maximum threshold to advance.
+    GAME_UPDATE_MAX_THRESHOLD = GAME_UPDATE_TIME_MS * GAME_MAX_UPDATES,
+};
+
+
 #ifdef __cplusplus
 extern "C"
 {

src/openrct2/game.c

@@ -294,8 +294,8 @@ void game_update()
     if (gGameSpeed > 1) {
         numUpdates = 1 << (gGameSpeed - 1);
     } else {
-        numUpdates = gTicksSinceLastUpdate / 31;
+        numUpdates = gTicksSinceLastUpdate / GAME_UPDATE_TIME_MS;
-        numUpdates = clamp(1, numUpdates, 4);
+        numUpdates = clamp(1, numUpdates, GAME_MAX_UPDATES);
     }
 
     if (network_get_mode() == NETWORK_MODE_CLIENT && network_get_status() == NETWORK_STATUS_CONNECTED && network_get_authstatus() == NETWORK_AUTH_OK) {

src/openrct2/title/TitleSequencePlayer.cpp

@@ -248,7 +248,7 @@ private:
             break;
         case TITLE_SCRIPT_WAIT:
             // The waitCounter is measured in 25-ms game ticks. Previously it was seconds * 40 ticks/second, now it is ms / 25 ms/tick
-            _waitCounter = Math::Max<sint32>(1, command->Milliseconds / UPDATE_TIME_MS);
+            _waitCounter = Math::Max<sint32>(1, command->Milliseconds / (uint32)GAME_UPDATE_TIME_MS);
             break;
         case TITLE_SCRIPT_LOADMM:
         {