Added ability to cycle through average frametime, FPS and average FPS

"t" and "Shift+t" are Lua bindings in common.lua
Maybe needs to be part of SettingsEngine instead, but the display code was already in RenderEngine, so it'll do for now on this branch

include/openspace/engine/wrapper/sgctwindowwrapper.h

@@ -42,6 +42,7 @@ public:
     bool windowHasResized() const override;
 
     double averageDeltaTime() const override;
+	double deltaTime() const override;
     glm::vec2 mousePosition() const override;
     uint32_t mouseButtons(int maxNumber) const override;
     glm::ivec2 currentWindowSize() const override;

include/openspace/engine/wrapper/windowwrapper.h

@@ -79,6 +79,12 @@ public:
      */
     virtual double averageDeltaTime() const;
 
+	/**
+	* Returns the frametime in seconds. On default, this method returns <code>0.0</code>.
+	* \return The frametime in seconds
+	*/
+	virtual double deltaTime() const;
+
     /**
      * Returns the location of the mouse cursor in pixel screen coordinates. On default,
      * this method returns <code>0,0</code>.

include/openspace/rendering/renderengine.h

@@ -68,8 +68,15 @@ public:
         Post
     };
 
+	enum class FrametimeType {
+		DtTimeAvg = 0,
+		FPS,
+		FPSAvg
+	};
+
     static const std::string KeyFontMono;
     static const std::string KeyFontLight;
+	static const std::vector<FrametimeType> FrametimeTypes;
 
     RenderEngine();
     ~RenderEngine();
@@ -97,6 +104,7 @@ public:
 
     void takeScreenshot();
     void toggleInfoText(bool b);
+	void toggleFrametimeType(int t);
 
     // Performance measurements
     void setPerformanceMeasurements(bool performanceMeasurements);
@@ -199,6 +207,8 @@ private:
     ghoul::Dictionary _resolveData;
     ScreenLog* _log;
 
+	FrametimeType _frametimeType;
+
     bool _showInfo;
     bool _showLog;
     bool _takeScreenshot;

scripts/common.lua

@@ -11,6 +11,9 @@ helper.setCommonKeys = function()
     openspace.bindKey("F2", "openspace.setPerformanceMeasurement(true)")
     openspace.bindKey("F3", "openspace.setPerformanceMeasurement(false)")
 
+    openspace.bindKey("t", "openspace.toggleFrametimeType(1)")
+    openspace.bindKey("Shift+t", "openspace.toggleFrametimeType(0)")
+
     openspace.bindKey("ESC", "openspace.toggleShutdown()")
 
     openspace.bindKey("PRINT_SCREEN", "openspace.takeScreenshot()")

src/engine/wrapper/sgctwindowwrapper.cpp

@@ -61,6 +61,10 @@ bool SGCTWindowWrapper::windowHasResized() const {
 double SGCTWindowWrapper::averageDeltaTime() const {
     return sgct::Engine::instance()->getAvgDt();
 }
+
+double SGCTWindowWrapper::deltaTime() const {
+	return sgct::Engine::instance()->getDt();
+}
     
 glm::vec2 SGCTWindowWrapper::mousePosition() const {
     int id = sgct::Engine::instance()->getCurrentWindowPtr()->getId();

src/engine/wrapper/windowwrapper.cpp

@@ -45,6 +45,10 @@ bool WindowWrapper::windowHasResized() const {
 double WindowWrapper::averageDeltaTime() const {
     return 0.0;
 }
+
+double WindowWrapper::deltaTime() const {
+	return 0.0;
+}
     
 glm::vec2 WindowWrapper::mousePosition() const {
     return glm::vec2(0.f);

src/rendering/renderengine.cpp

@@ -106,7 +106,12 @@ namespace openspace {
 
 const std::string RenderEngine::KeyFontMono = "Mono";
 const std::string RenderEngine::KeyFontLight = "Light";
-    
+const std::vector<RenderEngine::FrametimeType> RenderEngine::FrametimeTypes({
+	RenderEngine::FrametimeType::DtTimeAvg,
+	RenderEngine::FrametimeType::FPS,
+	RenderEngine::FrametimeType::FPSAvg
+});
+
 RenderEngine::RenderEngine()
     : _mainCamera(nullptr)
     , _sceneGraph(nullptr)
@@ -121,6 +126,7 @@ RenderEngine::RenderEngine()
     , _fadeDuration(2.f)
     , _currentFadeTime(0.f)
     , _fadeDirection(0)
+	, _frametimeType(FrametimeType::DtTimeAvg)
     //    , _sgctRenderStatisticsVisible(false)
 {
     _onScreenInformation = {
@@ -452,6 +458,18 @@ void RenderEngine::toggleInfoText(bool b) {
     _showInfo = b;
 }
 
+void RenderEngine::toggleFrametimeType(int t) {
+
+	std::vector<FrametimeType>::const_iterator it = std::find(
+		FrametimeTypes.begin(), FrametimeTypes.end(), _frametimeType);
+
+	if (!t && it == FrametimeTypes.begin()) {
+		it = FrametimeTypes.end();
+	}  
+	_frametimeType = t ? *(++it) : *(--it);
+
+}
+
 Scene* RenderEngine::scene() {
     // TODO custom assert (ticket #5)
     assert(_sceneGraph);
@@ -705,6 +723,12 @@ scripting::LuaLibrary RenderEngine::luaLibrary() {
                 "bool",
                 "Toggles the showing of render information on-screen text"
             },
+			{
+				"toggleFrametimeType",
+				&luascriptfunctions::toggleFrametimeType,
+				"int",
+				"Toggle showing FPS or Average Frametime in heads up info"
+			},
             {
                 "setPerformanceMeasurement",
                 &luascriptfunctions::setPerformanceMeasurement,
@@ -1239,11 +1263,36 @@ void RenderEngine::renderInformation() {
             Time::ref().deltaTime()
             );
 
-        RenderFontCr(*_fontInfo,
-            penPosition,
-            "Avg. Frametime: %.5f",
-            OsEng.windowWrapper().averageDeltaTime()
-            );
+		switch (_frametimeType) {
+			case FrametimeType::DtTimeAvg:
+				RenderFontCr(*_fontInfo,
+					penPosition,
+					"Avg. Frametime: %.5f",
+					OsEng.windowWrapper().averageDeltaTime()
+				);
+				break;
+			case FrametimeType::FPS:
+				RenderFontCr(*_fontInfo,
+					penPosition,
+					"FPS: %3.2f",
+					1.0 / OsEng.windowWrapper().deltaTime()
+				);
+				break;
+			case FrametimeType::FPSAvg:
+				RenderFontCr(*_fontInfo,
+					penPosition,
+					"Avg. FPS: %3.2f",
+					1.0 / OsEng.windowWrapper().averageDeltaTime()
+				);
+				break;
+			default:
+				RenderFontCr(*_fontInfo,
+					penPosition,
+					"Avg. Frametime: %.5f",
+					OsEng.windowWrapper().averageDeltaTime()
+				);
+				break;
+		}
 
 #ifdef OPENSPACE_MODULE_NEWHORIZONS_ENABLED
         bool hasNewHorizons = scene()->sceneGraphNode("NewHorizons");

src/rendering/renderengine_lua.inl

@@ -77,7 +77,7 @@ int setNAaSamples(lua_State* L) {
 /**
 * \ingroup LuaScripts
 * visualizeABuffer(bool):
-* Toggle the visualization of the ABuffer
+* Toggle heads-up info display on master node
 */
 int showRenderInformation(lua_State* L) {
     int nArguments = lua_gettop(L);
@@ -92,6 +92,24 @@ int showRenderInformation(lua_State* L) {
     return 0;
 }
 
+/**
+* \ingroup LuaScripts
+* toggleFramerateType(bool):
+* Cycle through showing FPS or Average Frametime in heads up info
+*/
+int toggleFrametimeType(lua_State* L) {
+	int nArguments = lua_gettop(L);
+	if (nArguments != 1)
+		return luaL_error(L, "Expected %i arguments, got %i", 1, nArguments);
+
+	const int type = lua_type(L, -1);
+	if (type != LUA_TNUMBER)
+		return luaL_error(L, "Expected argument of type 'number'");
+	int t = lua_tonumber(L, -1);
+	OsEng.renderEngine().toggleFrametimeType(t);
+	return 0;
+}
+
 /**
 * \ingroup LuaScripts
 * visualizeABuffer(bool):