IContextManager::activateContext can now also be used to reset the context.

The reset was prevented before, likely to make the use in beginScene easier. But it's necessary for using an OGL context from another thread.
Only implemented for WGL so far, GLX implementation will follow soon.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@5784 dfc29bdd-3216-0410-991c-e03cc46cb475

changes.txt

@@ -1,5 +1,6 @@
 --------------------------
 Changes in 1.9 (not yet released)
+- EditBox now still allows overwriting characters when the text-length is at max.
 - Bugfix: CMatrix4::transformPlane was calculating the wrong plane-normal before. 
 - SViewFrustum::recalculateBoundingBox no longer includes camera position in the bounding-box. Only using frustum corners now. Thx @DevSH for bugreport & patch.
 - Camera uses now OGL projection matrices with OpenGL driver. Fixes wrong near-plane values with OpenGL (showed too much before).

include/IContextManager.h

@@ -12,6 +12,7 @@ namespace irr
 {
 namespace video
 {
+	// For system specific window contexts (used for OpenGL)
 	class IContextManager : public virtual IReferenceCounted
 	{
 	public:
@@ -37,7 +38,15 @@ namespace video
 		virtual const SExposedVideoData& getContext() const =0;
 
 		//! Change render context, disable old and activate new defined by videoData
-		virtual bool activateContext(const SExposedVideoData& videoData) =0;
+		//\param restorePrimaryOnZero When true: restore original driver context when videoData is set to 0 values.
+		//                            When false: resets the context when videoData is set to 0 values.
+		/** This is mostly used internally by IVideoDriver::beginScene().
+			But if you want to switch threads which access your OpenGL driver you will have to
+			call this function as follows:
+			Old thread gives up context with: activateContext(irr::video::SExposedVideoData());
+			New thread takes over context with: activateContext(videoDriver->getExposedVideoData());
+			Note that only 1 thread at a time may access an OpenGL context.	*/
+		virtual bool activateContext(const SExposedVideoData& videoData, bool restorePrimaryOnZero=false) =0;
 
         //! Swap buffers.
         virtual bool swapBuffers() =0;

source/Irrlicht/CGLXManager.cpp

@@ -345,8 +345,10 @@ const SExposedVideoData& CGLXManager::getContext() const
 	return CurrentContext;
 }
 
-bool CGLXManager::activateContext(const SExposedVideoData& videoData)
+bool CGLXManager::activateContext(const SExposedVideoData& videoData, bool restorePrimaryOnZero)
 {
+	//TODO: handle restorePrimaryOnZero
+
 	if (videoData.OpenGLLinux.X11Window)
 	{
 		if (videoData.OpenGLLinux.X11Display && videoData.OpenGLLinux.X11Context)

source/Irrlicht/CGLXManager.h

@@ -55,7 +55,7 @@ namespace video
         const SExposedVideoData& getContext() const;
 
         //! Change render context, disable old and activate new defined by videoData
-        bool activateContext(const SExposedVideoData& videoData);
+        bool activateContext(const SExposedVideoData& videoData, bool restorePrimaryOnZero);
 
         // Swap buffers.
         bool swapBuffers();

source/Irrlicht/COpenGLDriver.cpp

@@ -72,7 +72,7 @@ bool COpenGLDriver::initDriver()
 	ContextManager->generateSurface();
 	ContextManager->generateContext();
 	ExposedData = ContextManager->getContext();
-	ContextManager->activateContext(ExposedData);
+	ContextManager->activateContext(ExposedData, false);
 
 	genericDriverInit();
 
@@ -288,7 +288,7 @@ bool COpenGLDriver::beginScene(u16 clearFlag, SColor clearColor, f32 clearDepth,
 	CNullDriver::beginScene(clearFlag, clearColor, clearDepth, clearStencil, videoData, sourceRect);
 
 	if (ContextManager)
-		ContextManager->activateContext(videoData);
+		ContextManager->activateContext(videoData, true);
 
 #if defined(_IRR_COMPILE_WITH_SDL_DEVICE_)
 	if ( DeviceType == EIDT_SDL )

source/Irrlicht/CWGLManager.cpp

@@ -179,7 +179,7 @@ bool CWGLManager::initialize(const SIrrlichtCreationParameters& params, const SE
 	CurrentContext.OpenGLWin32.HRc = hrc;
 	CurrentContext.OpenGLWin32.HWnd = temporary_wnd;
 
-	if (!activateContext(CurrentContext))
+	if (!activateContext(CurrentContext, false))
 	{
 		os::Printer::log("Cannot activate a temporary GL rendering context.", ELL_ERROR);
 		wglDeleteContext(hrc);
@@ -438,7 +438,7 @@ const SExposedVideoData& CWGLManager::getContext() const
 	return CurrentContext;
 }
 
-bool CWGLManager::activateContext(const SExposedVideoData& videoData)
+bool CWGLManager::activateContext(const SExposedVideoData& videoData, bool restorePrimaryOnZero)
 {
 	if (videoData.OpenGLWin32.HWnd && videoData.OpenGLWin32.HDc && videoData.OpenGLWin32.HRc)
 	{
@@ -449,6 +449,15 @@ bool CWGLManager::activateContext(const SExposedVideoData& videoData)
 		}
 		CurrentContext=videoData;
 	}
+	else if (!restorePrimaryOnZero && !videoData.OpenGLWin32.HDc && !videoData.OpenGLWin32.HRc)
+	{
+		if (!wglMakeCurrent((HDC)0, (HGLRC)0))
+		{
+			os::Printer::log("Render Context reset failed.");
+			return false;
+		}
+		CurrentContext = videoData;
+	}
 	// set back to main context
 	else if (!videoData.OpenGLWin32.HWnd && CurrentContext.OpenGLWin32.HDc != PrimaryContext.OpenGLWin32.HDc)
 	{

source/Irrlicht/CWGLManager.h

@@ -53,7 +53,7 @@ namespace video
 		const SExposedVideoData& getContext() const;
 
 		//! Change render context, disable old and activate new defined by videoData
-		bool activateContext(const SExposedVideoData& videoData);
+		bool activateContext(const SExposedVideoData& videoData, bool restorePrimaryOnZero);
 
         // Swap buffers.
         bool swapBuffers();