Renderer::GetClipRect() now returns Optional

Also add test for clipping rect

CHANGES.md

@@ -3,6 +3,9 @@ All notable changes to this project will be documented in this file.
 This project adheres to [Semantic Versioning](http://semver.org/).
 
 ## 0.13.0 - unreleased
+### Changed
+* ```Renderer::GetClipRect``` now returns ```Optional<Rect>``` instead of (possibly empty) ```Rect```
+
 ### Removed
 * Deprecated ```Renderer::GetInfo()``` variant which takes pointer (use variant which takes reference)
 

SDL2pp/Renderer.cc

@@ -352,10 +352,14 @@ bool Renderer::TargetSupported() const {
 	return SDL_RenderTargetSupported(renderer_) == SDL_TRUE;
 }
 
-Rect Renderer::GetClipRect() const {
+Optional<Rect> Renderer::GetClipRect() const {
 	SDL_Rect rect;
 	SDL_RenderGetClipRect(renderer_, &rect);
-	return rect;
+
+	if (SDL_RectEmpty(&rect))
+		return NullOpt;
+	else
+		return Rect(rect);
 }
 
 Point Renderer::GetLogicalSize() const {

SDL2pp/Renderer.hh

@@ -648,12 +648,13 @@ public:
 	////////////////////////////////////////////////////////////
 	/// \brief Get the clip rectangle for the current target
 	///
-	/// \returns Rect representing current clipping area
+	/// \returns Rect representing current clipping area or
+	///          NullOpt if clipping is disabled
 	///
 	/// \see http://wiki.libsdl.org/SDL_RenderGetClipRect
 	///
 	////////////////////////////////////////////////////////////
-	Rect GetClipRect() const;
+	Optional<Rect> GetClipRect() const;
 
 	////////////////////////////////////////////////////////////
 	/// \brief Get device independent resolution for rendering

tests/live_rendering.cc

@@ -205,6 +205,30 @@ BEGIN_TEST(int, char*[])
 		SDL_Delay(1000);
 	}
 
+	{
+		// Clip rect
+		renderer.SetDrawColor(0, 0, 0);
+		renderer.Clear();
+
+		renderer.SetClipRect(Rect(1, 1, 1, 1));
+
+		renderer.SetDrawColor(255, 255, 255);
+		renderer.FillRect(0, 0, 10, 10);
+
+		EXPECT_TRUE(renderer.GetClipRect() && renderer.GetClipRect() == Rect(1, 1, 1, 1));
+
+		renderer.SetClipRect(NullOpt);
+
+		EXPECT_TRUE(!renderer.GetClipRect());
+
+		pixels.Retrieve(renderer);
+
+		EXPECT_TRUE(pixels.Test3x3(1, 1, 0x020, 255, 255, 255));
+
+		renderer.Present();
+		SDL_Delay(1000);
+	}
+
 	{
 		// Blend
 		renderer.SetDrawColor(0, 0, 0);