Get the GLExtensions instance when a context is created

apps/opencs/view/render/scenewidget.cpp

@@ -48,6 +48,7 @@
 #include <components/debug/debuglog.hpp>
 #include <components/resource/resourcesystem.hpp>
 #include <components/resource/scenemanager.hpp>
+#include <components/sceneutil/glextensions.hpp>
 #include <components/sceneutil/lightmanager.hpp>
 
 #include "../widget/scenetoolmode.hpp"
@@ -76,6 +77,8 @@ namespace CSVRender
             = new osgViewer::GraphicsWindowEmbedded(0, 0, width(), height());
         mWidget->setGraphicsWindowEmbedded(window);
 
+        mRenderer->setRealizeOperation(new SceneUtil::GetGLExtensionsOperation());
+
         int frameRateLimit = CSMPrefs::get()["Rendering"]["framerate-limit"].toInt();
         mRenderer->setRunMaxFrameRate(frameRateLimit);
         mRenderer->setUseConfigureAffinity(false);

apps/openmw/engine.cpp

@@ -31,6 +31,7 @@
 #include <components/stereo/multiview.hpp>
 #include <components/stereo/stereomanager.hpp>
 
+#include <components/sceneutil/glextensions.hpp>
 #include <components/sceneutil/workqueue.hpp>
 
 #include <components/files/configurationmanager.hpp>
@@ -600,6 +601,7 @@ void OMW::Engine::createWindow()
     mViewer->setRealizeOperation(realizeOperations);
     osg::ref_ptr<IdentifyOpenGLOperation> identifyOp = new IdentifyOpenGLOperation();
     realizeOperations->add(identifyOp);
+    realizeOperations->add(new SceneUtil::GetGLExtensionsOperation());
 
     if (Debug::shouldDebugOpenGL())
         realizeOperations->add(new Debug::EnableGLDebugOperation());
@@ -780,13 +782,13 @@ void OMW::Engine::prepareEngine()
     // gui needs our shaders path before everything else
     mResourceSystem->getSceneManager()->setShaderPath(mResDir / "shaders");
 
-    osg::ref_ptr<osg::GLExtensions> exts = osg::GLExtensions::Get(0, false);
+    osg::GLExtensions& exts = SceneUtil::getGLExtensions();
-    bool shadersSupported = exts && (exts->glslLanguageVersion >= 1.2f);
+    bool shadersSupported = exts.glslLanguageVersion >= 1.2f;
 
 #if OSG_VERSION_LESS_THAN(3, 6, 6)
     // hack fix for https://github.com/openscenegraph/OpenSceneGraph/issues/1028
-    if (exts)
+    if (!osg::isGLExtensionSupported(exts.contextID, "NV_framebuffer_multisample_coverage"))
-        exts->glRenderbufferStorageMultisampleCoverageNV = nullptr;
+        exts.glRenderbufferStorageMultisampleCoverageNV = nullptr;
 #endif
 
     osg::ref_ptr<osg::Group> guiRoot = new osg::Group;

apps/openmw/mwrender/ripples.cpp

@@ -10,6 +10,7 @@
 #include <components/resource/scenemanager.hpp>
 #include <components/sceneutil/color.hpp>
 #include <components/sceneutil/depth.hpp>
+#include <components/sceneutil/glextensions.hpp>
 #include <components/shader/shadermanager.hpp>
 
 #include "../mwworld/ptr.hpp"
@@ -43,9 +44,9 @@ namespace MWRender
         mUseCompute = false;
 #else
         constexpr float minimumGLVersionRequiredForCompute = 4.4;
-        osg::GLExtensions* exts = osg::GLExtensions::Get(0, false);
+        osg::GLExtensions& exts = SceneUtil::getGLExtensions();
-        mUseCompute = exts->glVersion >= minimumGLVersionRequiredForCompute
+        mUseCompute = exts.glVersion >= minimumGLVersionRequiredForCompute
-            && exts->glslLanguageVersion >= minimumGLVersionRequiredForCompute;
+            && exts.glslLanguageVersion >= minimumGLVersionRequiredForCompute;
 #endif
 
         if (mUseCompute)

components/CMakeLists.txt

@@ -122,7 +122,7 @@ add_component_dir (sceneutil
     lightmanager lightutil positionattitudetransform workqueue pathgridutil waterutil writescene serialize optimizer
     detourdebugdraw navmesh agentpath shadow mwshadowtechnique recastmesh shadowsbin osgacontroller rtt
     screencapture depth color riggeometryosgaextension extradata unrefqueue lightcommon lightingmethod clearcolor
-    cullsafeboundsvisitor keyframe nodecallback textkeymap
+    cullsafeboundsvisitor keyframe nodecallback textkeymap glextensions
     )
 
 add_component_dir (nif

components/resource/imagemanager.cpp

@@ -5,6 +5,7 @@
 
 #include <components/debug/debuglog.hpp>
 #include <components/misc/pathhelpers.hpp>
+#include <components/sceneutil/glextensions.hpp>
 #include <components/vfs/manager.hpp>
 #include <components/vfs/pathutil.hpp>
 
@@ -65,12 +66,11 @@ namespace Resource
             case (GL_COMPRESSED_RGBA_S3TC_DXT3_EXT):
             case (GL_COMPRESSED_RGBA_S3TC_DXT5_EXT):
             {
-                osg::GLExtensions* exts = osg::GLExtensions::Get(0, false);
+                osg::GLExtensions& exts = SceneUtil::getGLExtensions();
-                if (exts
+                if (!exts.isTextureCompressionS3TCSupported
-                    && !exts->isTextureCompressionS3TCSupported
                     // This one works too. Should it be included in isTextureCompressionS3TCSupported()? Submitted as a
                     // patch to OSG.
-                    && !osg::isGLExtensionSupported(0, "GL_S3_s3tc"))
+                    && !osg::isGLExtensionSupported(exts.contextID, "GL_S3_s3tc"))
                 {
                     return false;
                 }

components/sceneutil/depth.cpp

@@ -4,6 +4,7 @@
 #include <array>
 
 #include <components/debug/debuglog.hpp>
+#include <components/sceneutil/glextensions.hpp>
 #include <components/settings/values.hpp>
 
 namespace SceneUtil
@@ -116,8 +117,7 @@ namespace SceneUtil
 
         if (Settings::camera().mReverseZ)
         {
-            osg::ref_ptr<osg::GLExtensions> exts = osg::GLExtensions::Get(0, false);
+            if (SceneUtil::getGLExtensions().isClipControlSupported)
-            if (exts && exts->isClipControlSupported)
             {
                 enableReverseZ = true;
                 Log(Debug::Info) << "Using reverse-z depth buffer";

components/sceneutil/glextensions.cpp

@@ -0,0 +1,28 @@
+#include "glextensions.hpp"
+
+namespace SceneUtil
+{
+    namespace
+    {
+        osg::observer_ptr<osg::GLExtensions> sGLExtensions;
+    }
+
+    osg::GLExtensions& getGLExtensions()
+    {
+        if (!sGLExtensions)
+            throw std::runtime_error(
+                "GetGLExtensionsOperation was not used when the current context was created or there is no current "
+                "context");
+        return *sGLExtensions;
+    }
+
+    GetGLExtensionsOperation::GetGLExtensionsOperation()
+        : GraphicsOperation("GetGLExtensionsOperation", false)
+    {
+    }
+
+    void GetGLExtensionsOperation::operator()(osg::GraphicsContext* graphicsContext)
+    {
+        sGLExtensions = graphicsContext->getState()->get<osg::GLExtensions>();
+    }
+}

components/sceneutil/glextensions.hpp

@@ -0,0 +1,20 @@
+#ifndef OPENMW_COMPONENTS_SCENEUTIL_GLEXTENSIONS_H
+#define OPENMW_COMPONENTS_SCENEUTIL_GLEXTENSIONS_H
+
+#include <osg/GLExtensions>
+#include <osg/GraphicsThread>
+
+namespace SceneUtil
+{
+    osg::GLExtensions& getGLExtensions();
+
+    class GetGLExtensionsOperation : public osg::GraphicsOperation
+    {
+    public:
+        GetGLExtensionsOperation();
+
+        void operator()(osg::GraphicsContext* graphicsContext) override;
+    };
+}
+
+#endif

components/sceneutil/lightmanager.cpp

@@ -13,6 +13,7 @@
 #include <osgUtil/CullVisitor>
 
 #include <components/resource/scenemanager.hpp>
+#include <components/sceneutil/glextensions.hpp>
 #include <components/sceneutil/util.hpp>
 #include <components/shader/shadermanager.hpp>
 
@@ -824,9 +825,9 @@ namespace SceneUtil
         , mPointLightFadeEnd(0.f)
         , mPointLightFadeStart(0.f)
     {
-        osg::GLExtensions* exts = osg::GLExtensions::Get(0, false);
+        osg::GLExtensions& exts = SceneUtil::getGLExtensions();
-        bool supportsUBO = exts && exts->isUniformBufferObjectSupported;
+        bool supportsUBO = exts.isUniformBufferObjectSupported;
-        bool supportsGPU4 = exts && exts->isGpuShader4Supported;
+        bool supportsGPU4 = exts.isGpuShader4Supported;
 
         mSupported[static_cast<int>(LightingMethod::FFP)] = true;
         mSupported[static_cast<int>(LightingMethod::PerObjectUniform)] = true;

components/sceneutil/mwshadowtechnique.cpp

@@ -30,6 +30,7 @@
 #include <deque>
 #include <vector>
 
+#include "glextensions.hpp"
 #include "shadowsbin.hpp"
 
 namespace {
@@ -920,8 +921,7 @@ void SceneUtil::MWShadowTechnique::setupCastingShader(Shader::ShaderManager & sh
     // This can't be part of the constructor as OSG mandates that there be a trivial constructor available
 
     osg::ref_ptr<osg::Shader> castingVertexShader = shaderManager.getShader("shadowcasting.vert");
-    osg::ref_ptr<osg::GLExtensions> exts = osg::GLExtensions::Get(0, false);
+    std::string useGPUShader4 = SceneUtil::getGLExtensions().isGpuShader4Supported ? "1" : "0";
-    std::string useGPUShader4 = exts && exts->isGpuShader4Supported ? "1" : "0";
     for (int alphaFunc = GL_NEVER; alphaFunc <= GL_ALWAYS; ++alphaFunc)
     {
         auto& program = _castingPrograms[alphaFunc - GL_NEVER];

components/shader/shadervisitor.cpp

@@ -22,6 +22,7 @@
 #include <components/misc/osguservalues.hpp>
 #include <components/misc/strings/algorithm.hpp>
 #include <components/resource/imagemanager.hpp>
+#include <components/sceneutil/glextensions.hpp>
 #include <components/sceneutil/morphgeometry.hpp>
 #include <components/sceneutil/riggeometry.hpp>
 #include <components/sceneutil/riggeometryosgaextension.hpp>
@@ -676,8 +677,7 @@ namespace Shader
                 defineMap["adjustCoverage"] = "1";
 
             // Preventing alpha tested stuff shrinking as lower mip levels are used requires knowing the texture size
-            osg::ref_ptr<osg::GLExtensions> exts = osg::GLExtensions::Get(0, false);
+            if (SceneUtil::getGLExtensions().isGpuShader4Supported)
-            if (exts && exts->isGpuShader4Supported)
                 defineMap["useGPUShader4"] = "1";
             // We could fall back to a texture size uniform if EXT_gpu_shader4 is missing
         }