added App flags, implemented v-sync and fixed timestep flags

include/blah/app.h

@@ -11,6 +11,15 @@ namespace Blah
 	// Application Logging Functions
 	using AppLogFn = Func<void, const char*, Log::Category>;
 
+	// Application flags
+	namespace Flags
+	{
+		constexpr u32 FixedTimestep = 1 << 0;
+		constexpr u32 VSync = 1 << 1;
+		constexpr u32 Fullscreen = 1 << 2;
+		constexpr u32 Resizable = 1 << 3;
+	}
+
 	// Application Configuration
 	struct Config
 	{
@@ -34,10 +43,13 @@ namespace Blah
 		// defaults to 5.
 		int max_updates = 5;
 
-		// target framerate.
+		// target framerate when running with Fixed Timestep
 		// defaults to 60.
 		int target_framerate = 60;
 
+		// default starting flags
+		u32 flags = Flags::VSync | Flags::Resizable | Flags::FixedTimestep;
+
 		// Callback on application startup
 		AppEventFn on_startup = nullptr;
 
@@ -113,9 +125,23 @@ namespace Blah
 		// If the window is currently focused or has mouse input
 		bool focused();
 
-		// Toggles fullscreen if supported on the platform.
-		// Otherwise this function does nothing.
-		void fullscreen(bool enabled);
+		// Toggles a specific flag
+		void set_flag(u32 flag, bool enabled);
+
+		// Gets whether a specific flag is enabled
+		bool get_flag(u32 flag);
+
+		// Toggles the fullscreen flag
+		inline void set_fullscreen(bool enabled) { set_flag(Flags::Fullscreen, enabled); }
+
+		// Toggles the V-Sync flag
+		inline void set_vsync(bool enabled) { set_flag(Flags::VSync, enabled); }
+
+		// Toggles the resizable flag
+		inline void set_resizable(bool enabled) { set_flag(Flags::Resizable, enabled); }
+
+		// Toggles whether to update with Fixed Timestep
+		inline void set_fixedtimestep(bool enabled) { set_flag(Flags::FixedTimestep, enabled); }
 
 		// Retrieves the Renderer Information
 		const RendererInfo& renderer();

src/app.cpp

@@ -28,6 +28,7 @@ namespace
 	bool       app_is_exiting = false;
 	u64        app_time_last;
 	u64        app_time_accumulator = 0;
+	u32        app_flags = 0;
 	TargetRef  app_backbuffer;
 
 	void get_drawable_size(int* w, int* h)
@@ -90,6 +91,7 @@ bool App::run(const Config* c)
 	// default values
 	app_is_running = true;
 	app_is_exiting = false;
+	app_flags = app_config.flags;
 	app_backbuffer = TargetRef(new BackBuffer());
 
 	// initialize the system
@@ -128,6 +130,10 @@ bool App::run(const Config* c)
 		}
 	}
 
+	// apply default flags
+	Internal::platform->set_app_flags(app_flags);
+	Internal::renderer->set_app_flags(app_flags);
+
 	// input + poll the platform once
 	Input::Internal::init();
 	Input::Internal::step_state();
@@ -164,14 +170,26 @@ bool App::is_running()
 
 void App::Internal::iterate()
 {
-	// update at a fixed timerate
-	// TODO: allow a non-fixed step update?
+	static const auto step = []()
+	{
+		Input::Internal::step_state();
+		platform->update(Input::state);
+		Input::Internal::update_bindings();
+		renderer->update();
+		if (app_config.on_update != nullptr)
+			app_config.on_update();
+	};
+
+	bool is_fixed_timestep = get_flag(Flags::FixedTimestep);
+
+	// Update in Fixed Timestep
+	if (is_fixed_timestep)
 	{
 		u64 time_target = (u64)((1.0 / app_config.target_framerate) * Time::ticks_per_second);
-		u64 time_curr = App::Internal::platform->ticks();
-		u64 time_diff = time_curr - app_time_last;
-		app_time_last = time_curr;
-		app_time_accumulator += time_diff;
+		u64 ticks_curr = App::Internal::platform->ticks();
+		u64 ticks_diff = ticks_curr - app_time_last;
+		app_time_last = ticks_curr;
+		app_time_accumulator += ticks_diff;
 
 		// do not let us run too fast
 		while (app_time_accumulator < time_target)
@@ -179,10 +197,10 @@ void App::Internal::iterate()
 			int milliseconds = (int)(time_target - app_time_accumulator) / (Time::ticks_per_second / 1000);
 			App::Internal::platform->sleep(milliseconds);
 
-			time_curr = App::Internal::platform->ticks();
-			time_diff = time_curr - app_time_last;
-			app_time_last = time_curr;
-			app_time_accumulator += time_diff;
+			ticks_curr = App::Internal::platform->ticks();
+			ticks_diff = ticks_curr - app_time_last;
+			app_time_last = ticks_curr;
+			app_time_accumulator += ticks_diff;
 		}
 
 		// Do not allow us to fall behind too many updates
@@ -212,23 +230,39 @@ void App::Internal::iterate()
 			Time::previous_seconds = Time::seconds;
 			Time::seconds += Time::delta;
 
-			Input::Internal::step_state();
-			platform->update(Input::state);
-			Input::Internal::update_bindings();
-			renderer->update();
+			step();
+		}
+	}
+	// Update with Variable Timestep
+	else
+	{
+		u64 ticks_curr = App::Internal::platform->ticks();
+		u64 ticks_diff = ticks_curr - app_time_last;
+		app_time_last = ticks_curr;
+		app_time_accumulator += ticks_diff;
 
-			if (app_config.on_update != nullptr)
-				app_config.on_update();
+		Time::delta = ticks_diff / (float)Time::ticks_per_second;
+
+		if (Time::pause_timer > 0)
+		{
+			Time::pause_timer -= Time::delta;
+		}
+		else
+		{
+			Time::previous_ticks = Time::ticks;
+			Time::ticks += ticks_diff;
+			Time::previous_seconds = Time::seconds;
+			Time::seconds += Time::delta;
+
+			step();
 		}
 	}
 
-	// render
+	// Draw Frame
 	{
 		renderer->before_render();
-
 		if (app_config.on_render != nullptr)
 			app_config.on_render();
-
 		renderer->after_render();
 		platform->present();
 	}
@@ -353,10 +387,28 @@ bool App::focused()
 	return Internal::platform->get_focused();
 }
 
-void App::fullscreen(bool enabled)
+void App::set_flag(u32 flag, bool enabled)
 {
 	BLAH_ASSERT_RUNNING();
-	Internal::platform->set_fullscreen(enabled);
+
+	u32 was = app_flags;
+
+	if (enabled)
+		app_flags |= flag;
+	else
+		app_flags &= ~flag;
+
+	if (was != app_flags)
+	{
+		Internal::platform->set_app_flags(app_flags);
+		Internal::renderer->set_app_flags(app_flags);
+	}
+}
+
+bool App::get_flag(u32 flag)
+{
+	BLAH_ASSERT_RUNNING();
+	return ((app_flags & flag) == flag);
 }
 
 const RendererInfo& App::renderer()

src/internal/platform.h

@@ -35,6 +35,9 @@ namespace Blah
 		// Called to present the window contents
 		virtual void present() = 0;
 
+		// Called when the App sets flags
+		virtual void set_app_flags(u32 flags) = 0;
+
 		// Gets the Application Window Title in UTF-8
 		virtual const char* get_title() = 0;
 
@@ -50,9 +53,6 @@ namespace Blah
 		// Gets whether the Window has focus
 		virtual bool get_focused() = 0;
 
-		// Sets the Window Fullscreen if enabled is not 0
-		virtual void set_fullscreen(bool enabled) = 0;
-
 		// Gets the Application Window Size, in Screen Coordinates
 		virtual void get_size(int* width, int* height) = 0;
 

src/internal/platform_sdl2.cpp

@@ -89,12 +89,12 @@ namespace Blah
 		void update(InputState& state) override;
 		void sleep(int milliseconds) override;
 		void present() override;
+		void set_app_flags(u32 flags) override;
 		const char* get_title() override;
 		void set_title(const char* title) override;
 		void get_position(int* x, int* y) override;
 		void set_position(int x, int y) override;
 		bool get_focused() override;
-		void set_fullscreen(bool enabled) override;
 		void get_size(int* width, int* height) override;
 		void set_size(int width, int height) override;
 		void get_draw_size(int* width, int* height) override;
@@ -158,7 +158,7 @@ bool SDL2_Platform::init(const Config& config)
 		return false;
 	}
 
-	int flags = SDL_WINDOW_ALLOW_HIGHDPI | SDL_WINDOW_HIDDEN | SDL_WINDOW_RESIZABLE;
+	int flags = SDL_WINDOW_ALLOW_HIGHDPI | SDL_WINDOW_HIDDEN;
 
 	// enable OpenGL
 	if (config.renderer_type == RendererType::OpenGL)
@@ -192,22 +192,12 @@ bool SDL2_Platform::init(const Config& config)
 		return false;
 	}
 
-	// set window properties
-	SDL_SetWindowResizable(window, SDL_TRUE);
-	SDL_SetWindowMinimumSize(window, 256, 256);
-
 	return true;
 }
 
 void SDL2_Platform::ready()
 {
-#ifndef __EMSCRIPTEN__
-	// enable V-Sync
-	// TODO:
-	// This should be a toggle or controllable in some way
-	if (App::renderer().type == RendererType::OpenGL)
-		SDL_GL_SetSwapInterval(1);
-#endif
+	
 }
 
 void SDL2_Platform::shutdown()
@@ -446,9 +436,7 @@ void SDL2_Platform::sleep(int milliseconds)
 void SDL2_Platform::present()
 {
 	if (App::renderer().type == RendererType::OpenGL)
-	{
 		SDL_GL_SwapWindow(window);
-	}
 
 	// display the window
 	// this avoids a short black screen on macoS
@@ -459,6 +447,21 @@ void SDL2_Platform::present()
 	}
 }
 
+void SDL2_Platform::set_app_flags(u32 flags)
+{
+	// Toggle Fullscreen
+	SDL_SetWindowFullscreen(window, ((flags & Flags::Fullscreen) != 0) ? SDL_WINDOW_FULLSCREEN_DESKTOP : 0);
+
+	// Toggle Resizable
+	SDL_SetWindowResizable(window, ((flags & Flags::Resizable) != 0) ? SDL_TRUE : SDL_FALSE);
+
+	// Toggle V-Sync for OpenGL
+#ifndef __EMSCRIPTEN__
+	if (App::renderer().type == RendererType::OpenGL)
+		SDL_GL_SetSwapInterval(((flags & Flags::VSync) != 0) ? 1 : 0);
+#endif
+}
+
 const char* SDL2_Platform::get_title()
 {
 	return SDL_GetWindowTitle(window);
@@ -485,14 +488,6 @@ bool SDL2_Platform::get_focused()
 	return (flags & SDL_WINDOW_INPUT_FOCUS) != 0 && (flags & SDL_WINDOW_MINIMIZED) == 0;
 }
 
-void SDL2_Platform::set_fullscreen(bool enabled)
-{
-	if (enabled)
-		SDL_SetWindowFullscreen(window, SDL_WINDOW_FULLSCREEN_DESKTOP);
-	else
-		SDL_SetWindowFullscreen(window, 0);
-}
-
 void SDL2_Platform::get_size(int* width, int* height)
 {
 	SDL_GetWindowSize(window, width, height);

src/internal/platform_win32.cpp

@@ -99,7 +99,7 @@ namespace Blah
 		void get_position(int* x, int* y) override;
 		void set_position(int x, int y) override;
 		bool get_focused() override;
-		void set_fullscreen(bool enabled) override;
+		void set_app_flags(u32 flags) override;
 		void get_size(int* width, int* height) override;
 		void set_size(int width, int height) override;
 		void get_draw_size(int* width, int* height) override;
@@ -474,11 +474,13 @@ bool Win32_Platform::get_focused()
 	return true;
 }
 
-void Win32_Platform::set_fullscreen(bool enabled)
+void Win32_Platform::set_app_flags(u32 flags)
 {
+	// toggle fullscreen
+	{
+		bool enabled = (flags & Flags::Fullscreen) != 0;
 		if (fullscreen == enabled)
 			return;
-
 		fullscreen = enabled;
 
 		if (fullscreen)
@@ -503,6 +505,10 @@ void Win32_Platform::set_fullscreen(bool enabled)
 		}
 	}
 
+	// toggle resizable
+	// TODO: ...
+}
+
 void Win32_Platform::get_size(int* width, int* height)
 {
 	RECT rect;

src/internal/renderer.h

@@ -32,6 +32,9 @@ namespace Blah
 		// Called after renderings ends
 		virtual void after_render() = 0;
 
+		// Called when the App sets flags
+		virtual void set_app_flags(u32 flags) { }
+
 		// Optional implementation to get the drawable backbuffer size in pixels.
 		// Not all implementations will use this so it can be up to the Platform.
 		virtual bool get_draw_size(int* w, int* h) { return false; }

src/internal/renderer_d3d11.cpp

@@ -932,7 +932,8 @@ namespace Blah
 
 	void Renderer_D3D11::after_render()
 	{
-		auto hr = swap_chain->Present(1, 0);
+		auto vsync = App::get_flag(Flags::VSync);
+		auto hr = swap_chain->Present(vsync ? 1 : 0, 0);
 		BLAH_ASSERT(SUCCEEDED(hr), "Failed to Present swap chain");
 	}