SaveTool: improve FPS capping mechanism.

src/SaveTool/SaveTool.cpp

@@ -128,15 +128,6 @@ SaveTool::SaveTool(const Arguments& arguments):
 
     initialiseConfiguration();
 
-    switch(_framelimit) {
-        case Framelimit::Vsync:
-            setSwapInterval(1);
-            break;
-        case Framelimit::HalfVsync:
-            setSwapInterval(2);
-            break;
-    }
-
     LOG_INFO("Initialising update checker.");
     curl_global_init(CURL_GLOBAL_DEFAULT);
     if(_checkUpdatesOnStartup) {
@@ -154,6 +145,8 @@ SaveTool::SaveTool(const Arguments& arguments):
         _uiState = UiState::Initialising;
         _initThread = std::thread{[this]{ initialiseManager(); }};
     }
+
+    _timeline.start();
 }
 
 SaveTool::~SaveTool() {
@@ -170,17 +163,8 @@ SaveTool::~SaveTool() {
     _conf.setValue("advanced_mode"_s, _advancedMode);
     _conf.setValue("startup_update_check"_s, _checkUpdatesOnStartup);
     _conf.setValue("skip_disclaimer"_s, _skipDisclaimer);
-
-    switch(_framelimit) {
-        case Framelimit::Vsync:
-            _conf.setValue("frame_limit"_s, "vsync"_s);
-            break;
-        case Framelimit::HalfVsync:
-            _conf.setValue("frame_limit"_s, "half_vsync"_s);
-            break;
-        default:
-            _conf.setValue("frame_limit"_s, "vsync"_s);
-    }
+    _conf.setValue("swap_interval"_s, _swapInterval);
+    _conf.setValue("fps_cap"_s, _fpsCap);
 
     _conf.save();
 
@@ -197,7 +181,14 @@ void SaveTool::drawEvent() {
     drawImGui();
 
     swapBuffers();
+
+    if(_swapInterval == 0 && _fpsCap < 301.0f) {
+        while(_timeline.currentFrameDuration() < (1.0f / _fpsCap));
+    }
+
     redraw();
+
+    _timeline.nextFrame();
 }
 
 void SaveTool::viewportEvent(ViewportEvent& event) {

src/SaveTool/SaveTool.h

@@ -23,7 +23,11 @@
 #include <Corrade/Containers/String.h>
 #include <Corrade/Utility/Configuration.h>
 #include <Corrade/Utility/Resource.h>
+#ifdef SAVETOOL_DEBUG_BUILD
+#include <Corrade/Utility/Tweakable.h>
+#endif
 
+#include <Magnum/Timeline.h>
 #include <Magnum/Platform/Sdl2Application.h>
 #include <Magnum/ImGuiIntegration/Context.h>
 
@@ -39,8 +43,6 @@
 #include "../ToastQueue/ToastQueue.h"
 
 #ifdef SAVETOOL_DEBUG_BUILD
-#include <Corrade/Utility/Tweakable.h>
-
 #define tw CORRADE_TWEAKABLE
 #endif
 
@@ -174,7 +176,7 @@ class SaveTool: public Platform::Sdl2Application, public efsw::FileWatchListener
           // Also, func should be a lambda if there are any default arguments, like ImGui::Button(), etc...
 
         template<typename... Args>
-        void drawUnsafeText(Containers::StringView text, Args... args) { // Alternative to the above, for ImGui::Text*() variants.
+        void drawUnsafeText(const char* text, Args... args) { // Alternative to the above, for ImGui::Text*() variants.
             if(_gameState != GameState::NotRunning) {
                 ImGui::TextDisabled(text, std::forward<Args>(args)...);
             }
@@ -260,10 +262,8 @@ class SaveTool: public Platform::Sdl2Application, public efsw::FileWatchListener
         };
         Containers::StaticArray<2, efsw::WatchID> _watchIDs;
 
-        enum class Framelimit: UnsignedByte {
-            Vsync,
-            HalfVsync
-        } _framelimit{Framelimit::Vsync};
+        int _swapInterval = 1;
+        float _fpsCap = 60.0f;
 
         bool _skipDisclaimer{false};
         bool _checkUpdatesOnStartup{true};
@@ -292,4 +292,6 @@ class SaveTool: public Platform::Sdl2Application, public efsw::FileWatchListener
 
         bool _cheatMode{false};
         bool _advancedMode{false};
+
+        Timeline _timeline;
 };

src/SaveTool/SaveTool_Initialisation.cpp

@@ -79,17 +79,31 @@ void SaveTool::initialiseConfiguration() {
         _conf.setValue("skip_disclaimer"_s, _skipDisclaimer);
     }
 
+    if(_conf.hasValue("swap_interval"_s)) {
+        _swapInterval = _conf.value<int>("swap_interval"_s);
+    }
+    else {
+        _conf.setValue("swap_interval"_s, 1);
+    }
+
+    if(_conf.hasValue("fps_cap"_s)) {
+        _fpsCap = _conf.value<float>("fps_cap");
+    }
+    else {
+        _conf.setValue("fps_cap", 60.0f);
+    }
+
     if(_conf.hasValue("frame_limit"_s)) {
         std::string frame_limit = _conf.value("frame_limit"_s);
         if(frame_limit == "half_vsync"_s) {
-            _framelimit = Framelimit::HalfVsync;
-        }
-        else {
-            _framelimit = Framelimit::Vsync;
+            _swapInterval = 2;
         }
+        _conf.removeValue("frame_limit"_s);
     }
-    else {
-        _conf.setValue("frame_limit"_s, "vsync"_s);
+
+    setSwapInterval(_swapInterval);
+    if(_swapInterval == 0) {
+        setMinimalLoopPeriod(0);
     }
 
     _conf.save();

src/SaveTool/SaveTool_drawMainMenu.cpp

@@ -55,31 +55,49 @@ void SaveTool::drawMainMenu() {
             ImGui::Separator();
 
             if(ImGui::BeginMenu(ICON_FA_COG " Settings")) {
-                drawAlignedText("Frame limiter:");
+                ImGui::BeginGroup();
+                drawAlignedText("Vertical sync:");
+                if(_swapInterval == 0) {
+                    drawAlignedText("FPS cap:");
+                }
+                ImGui::EndGroup();
+
                 ImGui::SameLine();
 
-                static auto selection = static_cast<UnsignedByte>(_framelimit);
-                static const char* framelimit_labels[2] = {
-                    "V-sync",
-                    "Half V-sync"
+                ImGui::BeginGroup();
+
+                static const char* framelimit_labels[] = {
+                    "Off",
+                    "Every VBLANK",
+                    "Every second VBLANK",
+                    "Every third VBLANK",
                 };
 
-                ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
-                if(ImGui::BeginCombo("##FrameLimit", framelimit_labels[selection])) {
-                    if(ImGui::Selectable(framelimit_labels[0], _framelimit == Framelimit::Vsync)) {
-                        selection = 0;
-                        _framelimit = Framelimit::Vsync;
-                        setSwapInterval(1);
-                    }
-                    if(ImGui::Selectable(framelimit_labels[1], _framelimit == Framelimit::HalfVsync)) {
-                        selection = 1;
-                        _framelimit = Framelimit::HalfVsync;
-                        setSwapInterval(2);
+                ImGui::PushItemWidth(300.0f);
+
+                if(ImGui::BeginCombo("##FrameLimit", framelimit_labels[_swapInterval])) {
+                    for(int i = 0; i <= 3; i++) {
+                        if(ImGui::Selectable(framelimit_labels[i], _swapInterval == i)) {
+                            _swapInterval = i;
+                            setSwapInterval(i);
+                            if(i == 0) {
+                                setMinimalLoopPeriod(0);
+                            }
+                        }
                     }
 
                     ImGui::EndCombo();
                 }
 
+                if(_swapInterval == 0) {
+                    ImGui::SliderFloat("##FpsCapSlider", &_fpsCap, 15.0f, 301.0f,
+                                       _fpsCap != 301.0f ? "%.0f" : "Uncapped", ImGuiSliderFlags_AlwaysClamp);
+                }
+
+                ImGui::PopItemWidth();
+
+                ImGui::EndGroup();
+
                 ImGui::Checkbox("Cheat mode", &_cheatMode);
                 ImGui::SameLine();
                 ImGui::AlignTextToFramePadding();