Disable OpenGL vsync when uncap fps option is enabled

src/drawing/IDrawingEngine.h

@@ -41,6 +41,8 @@ interface IDrawingEngine
     virtual void Resize(uint32 width, uint32 height) abstract;
     virtual void SetPalette(SDL_Color * colours)     abstract;
 
+    virtual void SetUncappedFrameRate(bool uncapped) abstract;
+
     virtual void    Invalidate(sint32 left, sint32 top, sint32 right, sint32 bottom) abstract;
     virtual void    Draw() abstract;
     virtual void    CopyRect(sint32 x, sint32 y, sint32 width, sint32 height, sint32 dx, sint32 dy) abstract;

src/drawing/NewDrawing.cpp

@@ -83,6 +83,7 @@ extern "C"
             try
             {
                 _drawingEngine->Initialise(gWindow);
+                _drawingEngine->SetUncappedFrameRate(gConfigGeneral.uncap_fps == 1);
             }
             catch (Exception ex)
             {
@@ -164,6 +165,14 @@ extern "C"
         }
     }
 
+    void drawing_engine_set_fps_uncapped(bool uncapped)
+    {
+        if (_drawingEngine != nullptr)
+        {
+            _drawingEngine->SetUncappedFrameRate(uncapped);
+        }
+    }
+
     void gfx_set_dirty_blocks(sint16 left, sint16 top, sint16 right, sint16 bottom)
     {
         if (_drawingEngine != nullptr)

src/drawing/NewDrawing.h

@@ -33,6 +33,7 @@ void drawing_engine_dispose();
 rct_drawpixelinfo * drawing_engine_get_dpi();
 bool drawing_engine_has_dirty_optimisations();
 void drawing_engine_invalidate_image(uint32 image);
+void drawing_engine_set_fps_uncapped(bool uncapped);
 
 #ifdef __cplusplus
 }

src/drawing/engines/SoftwareDrawingEngine.cpp

@@ -327,6 +327,11 @@ public:
         }
     }
 
+    void SetUncappedFrameRate(bool uncapped)
+    {
+        // Not applicable for this engine
+    }
+
     void Invalidate(sint32 left, sint32 top, sint32 right, sint32 bottom) override
     {
         left = Math::Max(left, 0);

src/drawing/engines/opengl/OpenGLDrawingEngine.cpp

@@ -47,6 +47,7 @@ IDrawingEngine * DrawingEngineFactory::CreateOpenGL()
 #include "../../IDrawingContext.h"
 #include "../../IDrawingEngine.h"
 #include "../../Rain.h"
+#include "../../../config.h"
 
 extern "C"
 {
@@ -317,6 +318,10 @@ public:
         _drawingContext->ResetPalette();
     }
 
+    void SetUncappedFrameRate(bool uncapped) {
+        SDL_GL_SetSwapInterval(uncapped ? 0 : 1);
+    }
+
     void Invalidate(sint32 left, sint32 top, sint32 right, sint32 bottom) override
     {
     }

src/windows/options.c

@@ -587,6 +587,7 @@ static void window_options_mouseup(rct_window *w, int widgetIndex)
 		switch (widgetIndex) {
 		case WIDX_UNCAP_FPS_CHECKBOX:
 			gConfigGeneral.uncap_fps ^= 1;
+            drawing_engine_set_fps_uncapped(gConfigGeneral.uncap_fps);
 			config_save_default();
 			window_invalidate(w);
 			break;