Merge pull request #2952 from Alexander-Wilms/develop

Enable VSync to prevent screen tearing while scrolling across map

client/gui/CGuiHandler.cpp

@@ -129,11 +129,10 @@ void CGuiHandler::renderFrame()
 
 		CCS->curh->render();
 
-		SDL_RenderPresent(mainRenderer);
-
 		windows().onFrameRendered();
 	}
 
+	SDL_RenderPresent(mainRenderer);
 	framerate().framerateDelay(); // holds a constant FPS
 }
 

client/gui/FramerateManager.cpp

@@ -11,11 +11,15 @@
 #include "StdInc.h"
 #include "FramerateManager.h"
 
+#include "../../lib/CConfigHandler.h"
+#include <SDL_video.h>
+
 FramerateManager::FramerateManager(int targetFrameRate)
 	: targetFrameTime(Duration(boost::chrono::seconds(1)) / targetFrameRate)
 	, lastFrameIndex(0)
 	, lastFrameTimes({})
-	, lastTimePoint (Clock::now())
+	, lastTimePoint(Clock::now())
+	, vsyncEnabled(settings["video"]["vsync"].Bool())
 {
 	boost::range::fill(lastFrameTimes, targetFrameTime);
 }
@@ -24,9 +28,14 @@ void FramerateManager::framerateDelay()
 {
 	Duration timeSpentBusy = Clock::now() - lastTimePoint;
 
-	// FPS is higher than it should be, then wait some time
+	if(!vsyncEnabled)
-	if(timeSpentBusy < targetFrameTime)
+	{
-		boost::this_thread::sleep_for(targetFrameTime - timeSpentBusy);
+		// if FPS is higher than it should be, then wait some time
+		if(timeSpentBusy < targetFrameTime)
+		{
+			boost::this_thread::sleep_for(targetFrameTime - timeSpentBusy);
+		}
+	}
 
 	// compute actual timeElapsed taking into account actual sleep interval
 	// limit it to 100 ms to avoid breaking animation in case of huge lag (e.g. triggered breakpoint)

client/gui/FramerateManager.h

@@ -25,6 +25,8 @@ class FramerateManager
 	/// index of last measured frome in lastFrameTimes array
 	ui32 lastFrameIndex;
 
+	bool vsyncEnabled;
+
 public:
 	FramerateManager(int targetFramerate);
 

client/renderSDL/ScreenHandler.cpp

@@ -274,8 +274,14 @@ void ScreenHandler::initializeWindow()
 		handleFatalError(message, true);
 	}
 
-	//create first available renderer if preferred not set. Use no flags, so HW accelerated will be preferred but SW renderer also will possible
+	// create first available renderer if no preferred one is set
-	mainRenderer = SDL_CreateRenderer(mainWindow, getPreferredRenderingDriver(), 0);
+	// use no SDL_RENDERER_SOFTWARE or SDL_RENDERER_ACCELERATED flag, so HW accelerated will be preferred but SW renderer will also be possible
+	uint32_t rendererFlags = 0;
+	if(settings["video"]["vsync"].Bool())
+	{
+		rendererFlags |= SDL_RENDERER_PRESENTVSYNC;
+	}
+	mainRenderer = SDL_CreateRenderer(mainWindow, getPreferredRenderingDriver(), rendererFlags);
 
 	if(mainRenderer == nullptr)
 		throw std::runtime_error("Unable to create renderer\n");

config/schemas/settings.json

@@ -149,7 +149,8 @@
 				"driver",
 				"displayIndex",
 				"showfps",
-				"targetfps"
+				"targetfps",
+				"vsync"
 			],
 			"properties" : {
 				"resolution" : {
@@ -207,6 +208,10 @@
 				"targetfps" : {
 					"type" : "number",
 					"default" : 60
+				},
+				"vsync" : {
+					"type" : "boolean",
+					"default" : true
 				}
 			}
 		},

launcher/settingsView/csettingsview_moc.cpp

@@ -83,6 +83,8 @@ void CSettingsView::loadSettings()
 
 	ui->spinBoxInterfaceScaling->setValue(settings["video"]["resolution"]["scaling"].Float());
 	ui->spinBoxFramerateLimit->setValue(settings["video"]["targetfps"].Float());
+	ui->spinBoxFramerateLimit->setDisabled(settings["video"]["vsync"].Bool());
+	ui->checkBoxVSync->setChecked(settings["video"]["vsync"].Bool());
 	ui->spinBoxReservedArea->setValue(std::round(settings["video"]["reservedWidth"].Float() * 100));
 
 	ui->comboBoxFriendlyAI->setCurrentText(QString::fromStdString(settings["server"]["friendlyAI"].String()));
@@ -494,6 +496,13 @@ void CSettingsView::on_spinBoxFramerateLimit_valueChanged(int arg1)
 	node->Float() = arg1;
 }
 
+void CSettingsView::on_checkBoxVSync_stateChanged(int arg1)
+{
+	Settings node = settings.write["video"]["vsync"];
+	node->Bool() = arg1;
+	ui->spinBoxFramerateLimit->setDisabled(settings["video"]["vsync"].Bool());
+}
+
 void CSettingsView::on_comboBoxEnemyPlayerAI_currentTextChanged(const QString &arg1)
 {
 	Settings node = settings.write["server"]["playerAI"];

launcher/settingsView/csettingsview_moc.h

@@ -62,6 +62,8 @@ private slots:
 
 	void on_spinBoxFramerateLimit_valueChanged(int arg1);
 
+	void on_checkBoxVSync_stateChanged(int arg1);
+
 	void on_comboBoxEnemyPlayerAI_currentTextChanged(const QString &arg1);
 
 	void on_comboBoxAlliedPlayerAI_currentTextChanged(const QString &arg1);