Add basic OpenGL debug callback

apps/openmw/engine.cpp

@@ -13,6 +13,7 @@
 #include <components/debug/debuglog.hpp>
 
 #include <components/misc/rng.hpp>
+#include <components/misc/gldebug.hpp>
 
 #include <components/vfs/manager.hpp>
 #include <components/vfs/registerarchives.hpp>
@@ -365,6 +366,7 @@ void OMW::Engine::createWindow(Settings::Manager& settings)
     checkSDLError(SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 8));
     checkSDLError(SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE, 0));
     checkSDLError(SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24));
+    checkSDLError(SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, SDL_GL_CONTEXT_DEBUG_FLAG));
 
     if (antialiasing > 0)
     {
@@ -425,6 +427,8 @@ void OMW::Engine::createWindow(Settings::Manager& settings)
     camera->setGraphicsContext(graphicsWindow);
     camera->setViewport(0, 0, width, height);
 
+    mViewer->setRealizeOperation(new EnableGLDebugOperation());
+
     mViewer->realize();
 
     mViewer->getEventQueue()->getCurrentEventState()->setWindowRectangle(0, 0, width, height);

components/CMakeLists.txt

@@ -86,7 +86,7 @@ add_component_dir (esmterrain
     )
 
 add_component_dir (misc
-    constants utf8stream stringops resourcehelpers rng messageformatparser weakcache
+    constants utf8stream stringops resourcehelpers rng messageformatparser weakcache gldebug
     )
 
 add_component_dir (debug

components/misc/gldebug.cpp

@@ -0,0 +1,60 @@
+#include "gldebug.hpp"
+
+#include <components/debug/debuglog.hpp>
+
+// OpenGL constants not provided by OSG:
+#define GL_DEBUG_OUTPUT 0x92E0
+#define GL_DEBUG_SEVERITY_MEDIUM 0x9147
+#define GL_DEBUG_TYPE_ERROR 0x824C
+
+void debugCallback(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const GLchar *message, const void *userParam)
+{
+    Log(Debug::Error) << message;
+}
+
+void enableGLDebugExtension(unsigned int contextID)
+{
+    typedef void (GL_APIENTRY *DEBUGPROC)(GLenum source, GLenum type, GLuint id, GLenum severity, GLsizei length, const GLchar *message, const void *userParam);
+    typedef void (GL_APIENTRY *GLDebugMessageControlFunction)(GLenum source, GLenum type, GLenum severity, GLsizei count, const GLuint *ids, GLboolean enabled);
+    typedef void (GL_APIENTRY *GLDebugMessageCallbackFunction)(DEBUGPROC, const void* userParam);
+    
+    GLDebugMessageControlFunction glDebugMessageControl = nullptr;
+    GLDebugMessageCallbackFunction glDebugMessageCallback = nullptr;
+
+    if (osg::isGLExtensionSupported(contextID, "GL_KHR_debug"))
+    {
+        osg::setGLExtensionFuncPtr(glDebugMessageCallback, "glDebugMessageCallback");
+        osg::setGLExtensionFuncPtr(glDebugMessageControl, "glDebugMessageControl");
+    }
+    else if (osg::isGLExtensionSupported(contextID, "GL_ARB_debug_output"))
+    {
+        osg::setGLExtensionFuncPtr(glDebugMessageCallback, "glDebugMessageCallbackARB");
+        osg::setGLExtensionFuncPtr(glDebugMessageControl, "glDebugMessageControlARB");
+    }
+    else if (osg::isGLExtensionSupported(contextID, "GL_AMD_debug_output"))
+    {
+        osg::setGLExtensionFuncPtr(glDebugMessageCallback, "glDebugMessageCallbackAMD");
+        osg::setGLExtensionFuncPtr(glDebugMessageControl, "glDebugMessageControlAMD");
+    }
+
+    if (glDebugMessageCallback && glDebugMessageControl)
+    {
+        glEnable(GL_DEBUG_OUTPUT);
+        glDebugMessageControl(GL_DONT_CARE, GL_DEBUG_TYPE_ERROR, GL_DEBUG_SEVERITY_MEDIUM, 0, nullptr, true);
+        glDebugMessageCallback(debugCallback, nullptr);
+
+        Log(Debug::Info) << "OpenGL debug callback attached.";
+    }
+}
+
+EnableGLDebugOperation::EnableGLDebugOperation() : osg::GraphicsOperation("EnableGLDebugOperation", false)
+{
+}
+
+void EnableGLDebugOperation::operator()(osg::GraphicsContext* graphicsContext)
+{
+    OpenThreads::ScopedLock<OpenThreads::Mutex> lock(mMutex);
+
+    unsigned int contextID = graphicsContext->getState()->getContextID();
+    enableGLDebugExtension(contextID);
+}

components/misc/gldebug.hpp

@@ -0,0 +1,16 @@
+#ifndef OPENMW_COMPONENTS_MISC_GLDEBUG_H
+#define OPENMW_COMPONENTS_MISC_GLDEBUG_H
+
+#include <osgViewer/ViewerEventHandlers>
+
+class EnableGLDebugOperation : public osg::GraphicsOperation
+{
+public:
+    EnableGLDebugOperation();
+
+    virtual void operator()(osg::GraphicsContext* graphicsContext);
+
+private:
+    OpenThreads::Mutex mMutex;
+};
+#endif