Fix for render context change where only the window id is given. We now try to...

Fix for render context change where only the window id is given. We now try to change only the window ID, keeping context and display unchanged. Suggestion by vovo4ka from the forum.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@4094 dfc29bdd-3216-0410-991c-e03cc46cb475

source/Irrlicht/COpenGLDriver.cpp

@@ -517,7 +517,9 @@ COpenGLDriver::COpenGLDriver(const SIrrlichtCreationParameters& params,
 
 bool COpenGLDriver::changeRenderContext(const SExposedVideoData& videoData, CIrrDeviceLinux* device)
 {
-	if (videoData.OpenGLLinux.X11Display && videoData.OpenGLLinux.X11Window && videoData.OpenGLLinux.X11Context)
+	if (videoData.OpenGLLinux.X11Window)
+	{
+		if (videoData.OpenGLLinux.X11Display && videoData.OpenGLLinux.X11Context)
 		{
 			if (!glXMakeCurrent((Display*)videoData.OpenGLLinux.X11Display, videoData.OpenGLLinux.X11Window, (GLXContext)videoData.OpenGLLinux.X11Context))
 			{
@@ -530,6 +532,21 @@ bool COpenGLDriver::changeRenderContext(const SExposedVideoData& videoData, CIrr
 				X11Display = (Display*)videoData.OpenGLLinux.X11Display;
 			}
 		}
+		else
+		{
+			// in case we only got a window ID, try with the existing values for display and context
+			if (!glXMakeCurrent((Display*)ExposedData.OpenGLLinux.X11Display, videoData.OpenGLLinux.X11Window, (GLXContext)ExposedData.OpenGLLinux.X11Context))
+			{
+				os::Printer::log("Render Context switch failed.");
+				return false;
+			}
+			else
+			{
+				Drawable = videoData.OpenGLLinux.X11Window;
+				X11Display = (Display*)ExposedData.OpenGLLinux.X11Display;
+			}
+		}
+	}
 	// set back to main context
 	else if (X11Display != ExposedData.OpenGLLinux.X11Display)
 	{