Allow changing OpenGL RTT mode, useful for example if the driver reports incorrect capabilities

apps/openmw/engine.cpp

@@ -299,6 +299,7 @@ void OMW::Engine::go()
     mOgre->configure(
         mCfgMgr.getLogPath().string(),
         renderSystem,
+        Settings::Manager::getString("opengl rtt mode", "Video"),
         false);
 
     // This has to be added BEFORE MyGUI is initialized, as it needs

files/settings-default.cfg

@@ -24,6 +24,10 @@ antialiasing = none
 
 vsync = false
 
+# opengl render to texture mode, valid options:
+# PBuffer, FBO, Copy
+opengl rtt mode = FBO
+
 [GUI]
 # 1 is fully opaque
 menu transparency = 0.84

libs/openengine/ogre/renderer.cpp

@@ -145,6 +145,7 @@ float OgreRenderer::getFPS()
 
 void OgreRenderer::configure(const std::string &logPath,
                             const std::string& renderSystem,
+                             const std::string& rttMode,
                             bool _logging)
 {
     // Set up logging first
@@ -198,6 +199,9 @@ void OgreRenderer::configure(const std::string &logPath,
     if (rs == 0)
         throw std::runtime_error ("RenderSystem with name " + renderSystem + " not found, make sure the plugins are loaded");
     mRoot->setRenderSystem(rs);
+
+    if (rs->getName().find("OpenGL") != std::string::npos)
+        rs->setConfigOption ("RTT Preferred Mode", rttMode);
 }
 
 void OgreRenderer::createWindow(const std::string &title, const WindowSettings& settings)

libs/openengine/ogre/renderer.hpp

@@ -132,6 +132,7 @@ namespace OEngine
             void configure(
                 const std::string &logPath, // Path to directory where to store log files
                 const std::string &renderSystem,
+                const std::string &rttMode,
                 bool _logging);      // Enable or disable logging
 
             /// Create a window with the given title