From b8089b6e276b7c298d17a4360dea6a49cabf7a21 Mon Sep 17 00:00:00 2001
From: Pavel Rojtberg <rojtberg@gmail.com>
Date: Tue, 7 Feb 2023 18:44:07 +0100
Subject: [PATCH] GLSupport: EGL - fix multi-window operation

---
 RenderSystems/GLSupport/src/EGL/OgreEGLContext.cpp       | 3 +++
 RenderSystems/GLSupport/src/EGL/OgreEGLWindow.cpp        | 2 +-
 RenderSystems/GLSupport/src/EGL/X11/OgreX11EGLWindow.cpp | 9 +--------
 3 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/RenderSystems/GLSupport/src/EGL/OgreEGLContext.cpp b/RenderSystems/GLSupport/src/EGL/OgreEGLContext.cpp
index 35ee41f51b5..9277d4eb125 100644
--- a/RenderSystems/GLSupport/src/EGL/OgreEGLContext.cpp
+++ b/RenderSystems/GLSupport/src/EGL/OgreEGLContext.cpp
@@ -129,6 +129,9 @@ namespace Ogre {
 
     void EGLContext::setCurrent()
     {
+        if(eglGetCurrentSurface(EGL_DRAW) == mDrawable)
+            return;
+
         EGLBoolean ret = eglMakeCurrent(mEglDisplay,
                                         mDrawable, mDrawable, mContext);
         EGL_CHECK_ERROR
diff --git a/RenderSystems/GLSupport/src/EGL/OgreEGLWindow.cpp b/RenderSystems/GLSupport/src/EGL/OgreEGLWindow.cpp
index 6d11662eb88..0c5d9323e51 100644
--- a/RenderSystems/GLSupport/src/EGL/OgreEGLWindow.cpp
+++ b/RenderSystems/GLSupport/src/EGL/OgreEGLWindow.cpp
@@ -119,7 +119,7 @@ namespace Ogre {
         {
             return;
         }
-
+        mContext->setCurrent();
         if (eglSwapBuffers(mEglDisplay, mEglSurface) == EGL_FALSE)
         {
             EGL_CHECK_ERROR
diff --git a/RenderSystems/GLSupport/src/EGL/X11/OgreX11EGLWindow.cpp b/RenderSystems/GLSupport/src/EGL/X11/OgreX11EGLWindow.cpp
index 424bee909da..54b8ab168b2 100644
--- a/RenderSystems/GLSupport/src/EGL/X11/OgreX11EGLWindow.cpp
+++ b/RenderSystems/GLSupport/src/EGL/X11/OgreX11EGLWindow.cpp
@@ -268,8 +268,6 @@ namespace Ogre {
                                 "EGLWindow::create");
                 }
 
-                mEglSurface = eglGetCurrentSurface(EGL_DRAW);
-                EGL_CHECK_ERROR
                 mEglDisplay = eglGetCurrentDisplay();
                 EGL_CHECK_ERROR
             }
@@ -339,8 +337,6 @@ namespace Ogre {
             }
         }
 
-        mIsExternal = (mEglSurface != 0);
-
         if (!mEglConfig)
         {
             int minAttribs[] = {
@@ -381,10 +377,7 @@ namespace Ogre {
             mGLSupport->switchMode (width, height, frequency);
         }
 
-        if (!mIsExternal)
-        {
-            createNativeWindow(left, top, width, height, title);
-        }
+        createNativeWindow(left, top, width, height, title);
 
         mContext = createEGLContext(eglContext);