# HG changeset patch
# User prock@33b003aa-7bff-0310-803a-e67f0ece8222
# Date 1286380193 0
# Node ID 5f381fa3476997795401e63d4985040789e82430
# Parent  46b95d06c8c2f7b1bf9ae647c734985d3b213c66
  * Added the clearBackBuffer() function to the renderbackends.
  * Renamed setClearScreen() to setClearBackBuffer()
  * The SDL render backend now honors what was set with setClearBackBuffer()
  * Documented testRenderedViewPort()
  * The OpenGL backend no longer clears the screen every frame by default.  testRenderedViewPort() takes care of clearing the screen for now.  Note: if the user overrides the default and enables clearing of the backbuffer that it may be cleared twice in one frame (OpenGL only)!

diff -r 46b95d06c8c2 -r 5f381fa34769 engine/core/video/opengl/renderbackendopengl.cpp
--- a/engine/core/video/opengl/renderbackendopengl.cpp	Wed Oct 06 14:09:24 2010 +0000
+++ b/engine/core/video/opengl/renderbackendopengl.cpp	Wed Oct 06 15:49:53 2010 +0000
@@ -43,7 +43,7 @@
 
 		m_rgba_format = *(testsurface->format);
 		SDL_FreeSurface(testsurface);
-		m_clear = true;
+		m_clear = false;
 	}
 
 	const std::string& RenderBackendOpenGL::getName() const {
@@ -64,6 +64,11 @@
 		SDL_EnableKeyRepeat(SDL_DEFAULT_REPEAT_DELAY, SDL_DEFAULT_REPEAT_INTERVAL); // temporary hack
 	}
 
+	void RenderBackendOpenGL::clearBackBuffer() {
+		GLDisable flag(GL_SCISSOR_TEST);
+		glClear(GL_COLOR_BUFFER_BIT);
+	}
+
 	Image* RenderBackendOpenGL::createMainScreen(unsigned int width, unsigned int height, unsigned char bitsPerPixel, bool fs, const std::string& title, const std::string& icon) {
 		delete m_screen;
 		m_screen = 0;
@@ -134,8 +139,7 @@
 
 	void RenderBackendOpenGL::startFrame() {
 		if(m_clear) {
-			GLDisable flag(GL_SCISSOR_TEST);
-			glClear(GL_COLOR_BUFFER_BIT);
+			clearBackBuffer();
 		}
 	}
 
diff -r 46b95d06c8c2 -r 5f381fa34769 engine/core/video/opengl/renderbackendopengl.h
--- a/engine/core/video/opengl/renderbackendopengl.h	Wed Oct 06 14:09:24 2010 +0000
+++ b/engine/core/video/opengl/renderbackendopengl.h	Wed Oct 06 15:49:53 2010 +0000
@@ -45,6 +45,8 @@
 		void startFrame();
 		void endFrame();
 		void init();
+		void clearBackBuffer();
+
 		Image* createMainScreen(unsigned int width, unsigned int height, unsigned char bitsPerPixel, bool fullscreen, const std::string& title, const std::string& icon);
 		Image* createImage(const uint8_t* data, unsigned int width, unsigned int height);
 		Image* createImage(SDL_Surface* surface);
diff -r 46b95d06c8c2 -r 5f381fa34769 engine/core/video/renderbackend.cpp
--- a/engine/core/video/renderbackend.cpp	Wed Oct 06 14:09:24 2010 +0000
+++ b/engine/core/video/renderbackend.cpp	Wed Oct 06 15:49:53 2010 +0000
@@ -34,6 +34,7 @@
 
 	RenderBackend::RenderBackend(const SDL_Color& colorkey):
 		m_screen(NULL),
+		m_clear(false),
 		m_isalphaoptimized(false),
 		m_iscolorkeyenabled(false),
 		m_colorkey(colorkey) {
diff -r 46b95d06c8c2 -r 5f381fa34769 engine/core/video/renderbackend.h
--- a/engine/core/video/renderbackend.h	Wed Oct 06 14:09:24 2010 +0000
+++ b/engine/core/video/renderbackend.h	Wed Oct 06 15:49:53 2010 +0000
@@ -75,6 +75,10 @@
 		 */
 		virtual void init() = 0;
 
+		/** Forces a clear of the backbuffer
+		 */
+		virtual void clearBackBuffer() = 0;
+
 		/** Performs cleanup actions.
 		 */
 		virtual void deinit();
@@ -103,11 +107,6 @@
 		 */
 		virtual Image* createImage(SDL_Surface* surface) = 0;
 
-		/** Sets if the screen (backbuffer) should be cleared before rendering the next frame
-		 * @param clear true = clear screen before next frame, false = do not clear screen
-		 */
-		void setClearScreen(bool clear) { m_clear = clear; };
-
 		/** Returns a pointer to the main screen Image
 		 * @return A pointer to the main screen Image, or 0 if no mainscreen exists.
 		 */
@@ -147,6 +146,11 @@
 		 */
 		const SDL_Color& getColorKey() const;
 
+		/** Sets if the backbuffer should be cleared before rendering the next frame.
+		 * @param clear true = clear screen before next frame, false = do not clear screen
+		 */
+		void setClearBackBuffer(bool clear) { m_clear = clear; };
+
 	protected:
 		Image* m_screen;
 		bool m_clear;
diff -r 46b95d06c8c2 -r 5f381fa34769 engine/core/video/sdl/renderbackendsdl.cpp
--- a/engine/core/video/sdl/renderbackendsdl.cpp	Wed Oct 06 14:09:24 2010 +0000
+++ b/engine/core/video/sdl/renderbackendsdl.cpp	Wed Oct 06 15:49:53 2010 +0000
@@ -60,6 +60,16 @@
 		SDL_EnableKeyRepeat(SDL_DEFAULT_REPEAT_DELAY, SDL_DEFAULT_REPEAT_INTERVAL); // temporary hack
 	}
 
+	void RenderBackendSDL::clearBackBuffer() {
+		SDL_Rect rect;
+		rect.x = 0;
+		rect.y = 0;
+		rect.w = getWidth();
+		rect.h = getHeight();
+		SDL_SetClipRect(m_screen->getSurface(), &rect);
+		SDL_FillRect(m_screen->getSurface(), 0, 0x00);
+	}
+
 	Image* RenderBackendSDL::createMainScreen(unsigned int width, unsigned int height, unsigned char bitsPerPixel, bool fs, const std::string& title, const std::string& icon) {
 		Uint32 flags = 0;
 		if (fs) {
@@ -120,13 +130,9 @@
 	}
 
 	void RenderBackendSDL::startFrame() {
-		SDL_Rect rect;
-		rect.x = 0;
-		rect.y = 0;
-		rect.w = getWidth();
-		rect.h = getHeight();
-		SDL_SetClipRect(m_screen->getSurface(), &rect);
-		SDL_FillRect(m_screen->getSurface(), 0, 0x00);
+		if (m_clear) {
+			clearBackBuffer();
+		}
 	}
 
 	void RenderBackendSDL::endFrame() {
diff -r 46b95d06c8c2 -r 5f381fa34769 engine/core/video/sdl/renderbackendsdl.h
--- a/engine/core/video/sdl/renderbackendsdl.h	Wed Oct 06 14:09:24 2010 +0000
+++ b/engine/core/video/sdl/renderbackendsdl.h	Wed Oct 06 15:49:53 2010 +0000
@@ -47,6 +47,8 @@
 		void startFrame();
 		void endFrame();
 		void init();
+		void clearBackBuffer();
+
 		Image* createMainScreen(unsigned int width, unsigned int height, unsigned char bitsPerPixel, bool fullscreen, const std::string& title, const std::string& icon);
 		Image* createImage(const uint8_t* data, unsigned int width, unsigned int height);
 		Image* createImage(SDL_Surface* surface);
diff -r 46b95d06c8c2 -r 5f381fa34769 engine/core/video/video.i
--- a/engine/core/video/video.i	Wed Oct 06 14:09:24 2010 +0000
+++ b/engine/core/video/video.i	Wed Oct 06 15:49:53 2010 +0000
@@ -172,7 +172,7 @@
 		bool isColorKeyEnabled() const;
 		void setColorKey(const SDL_Color& colorkey);
 		const SDL_Color& getColorKey() const;
-		void setClearScreen(bool clear);
+		void setClearBackBuffer(bool clear);
 	};
 	
 	enum MouseCursorType {
diff -r 46b95d06c8c2 -r 5f381fa34769 engine/core/view/camera.cpp
--- a/engine/core/view/camera.cpp	Wed Oct 06 14:09:24 2010 +0000
+++ b/engine/core/view/camera.cpp	Wed Oct 06 15:49:53 2010 +0000
@@ -129,7 +129,7 @@
 			delete r_it->second;
 		}
 		m_renderers.clear();
-		m_renderbackend->setClearScreen(true);
+		m_renderbackend->setClearBackBuffer(true);
 		delete m_map_observer;
 	}
 
@@ -448,10 +448,9 @@
 		}
 
 		if(trec1 && trec2 && trec3 && trec4) {
-			m_renderbackend->setClearScreen(false);
 			return false;
 		}
-		m_renderbackend->setClearScreen(true);
+		m_renderbackend->clearBackBuffer();
 		return true;
 	}
 
diff -r 46b95d06c8c2 -r 5f381fa34769 engine/core/view/camera.h
--- a/engine/core/view/camera.h	Wed Oct 06 14:09:24 2010 +0000
+++ b/engine/core/view/camera.h	Wed Oct 06 15:49:53 2010 +0000
@@ -278,10 +278,15 @@
 		void onRendererPipelinePositionChanged(RendererBase* renderer);
 		void onRendererEnabledChanged(RendererBase* renderer);
 
+		/** Use with OpenGL only! Checks to see if the entire viewport was rendered last frame.
+		 * If so it wont clear the backbuffer.
+		 */
 		bool testRenderedViewPort();
+
 		/** Renders camera
 		 */
 		void render();
+
 	private:
 		friend class MapObserver;
 		void addLayer(Layer* layer);