Reduce texture memory usage in OpenMW

apps/openmw/engine.cpp

@@ -17,6 +17,7 @@
 #include <components/vfs/registerarchives.hpp>
 
 #include <components/resource/resourcesystem.hpp>
+#include <components/resource/texturemanager.hpp>
 
 #include <components/compiler/extensions0.hpp>
 
@@ -307,6 +308,7 @@ void OMW::Engine::prepareEngine (Settings::Manager & settings)
     VFS::registerArchives(mVFS.get(), mFileCollections, mArchives, true);
 
     mResourceSystem.reset(new Resource::ResourceSystem(mVFS.get()));
+    mResourceSystem->getTextureManager()->setUnRefImageDataAfterApply(true);
 
     // Create input and UI first to set up a bootstrapping environment for
     // showing a loading screen and keeping the window responsive while doing so

components/resource/texturemanager.cpp

@@ -37,10 +37,16 @@ namespace Resource
     TextureManager::TextureManager(const VFS::Manager *vfs)
         : mVFS(vfs)
         , mWarningTexture(createWarningTexture())
+        , mUnRefImageDataAfterApply(false)
     {
 
     }
 
+    void TextureManager::setUnRefImageDataAfterApply(bool unref)
+    {
+        mUnRefImageDataAfterApply = unref;
+    }
+
     /*
     osg::ref_ptr<osg::Image> TextureManager::getImage(const std::string &filename)
     {
@@ -91,8 +97,7 @@ namespace Resource
             texture->setWrap(osg::Texture::WRAP_S, wrapS);
             texture->setWrap(osg::Texture::WRAP_T, wrapT);
 
-            // Can be enabled for single-context, i.e. in openmw
-            //texture->setUnRefImageDataAfterApply(true);
+            texture->setUnRefImageDataAfterApply(mUnRefImageDataAfterApply);
 
             mTextures.insert(std::make_pair(key, texture));
             return texture;

components/resource/texturemanager.hpp

@@ -24,6 +24,10 @@ namespace Resource
 
         // TODO: texture filtering settings
 
+        /// Keep a copy of the texture data around in system memory? This is needed when using multiple graphics contexts,
+        /// otherwise should be disabled to reduce memory usage.
+        void setUnRefImageDataAfterApply(bool unref);
+
         /// Create or retrieve a Texture2D using the specified image filename, and wrap parameters.
         osg::ref_ptr<osg::Texture2D> getTexture2D(const std::string& filename, osg::Texture::WrapMode wrapS, osg::Texture::WrapMode wrapT);
 
@@ -43,6 +47,7 @@ namespace Resource
 
         osg::ref_ptr<osg::Texture2D> mWarningTexture;
 
+        bool mUnRefImageDataAfterApply;
     };
 
 }