Opengl Error Reporting
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that makes Error Checking from functions easier. Note that this feature, which is core in 4.3, has functionality that is generally exposed by two different extensions. The KHR opengl debug output extension is the core feature, which is always advertised when available. The other gldebugmessagecallback two are generally only advertised when the OpenGL Context was created with the WGL/GLX_DEBUG_CONTEXT_BIT. This page describes the
Gldebugmessagecallback Example
KHR/core functionality. The ARB/AMD version contains only the message log part, without the object names or the scoped messages. They also have some slight differences in the callback function parameters and
Gldebugmessagecontrol
the types of messages they work with. Contents 1 Message 1.1 User messages 1.2 Getting messages 1.3 Logging 1.4 Message filtering 1.5 Scoping messages 2 Object names Message The heart of debug output is a message. Messages are generated when certain things happen in the OpenGL implementation; the user can even generate message of their own. In order to have messages khr_debug example generated at all, debug output must first be enabled. If the context is a debug context (ie: GL_CONTEXT_FLAG_DEBUG_BIT is part of the GL_CONTEXT_FLAGS state), then debug output is already enabled. Otherwise it starts disabled and must be enabled with an explicit glEnable(GL_DEBUG_OUTPUT). Messages can come from a variety of sources, but they each contain the following data: The source that produced the message, by GLenum. The type of message, by GLenum. The message severity (how important it is), by GLenum. An ID, as a GLuint. A null-terminated string describing the message. Implementations may create messages at their discretion. In debug contexts, the implementation is required to generate messages for OpenGL Errors and GLSL compilation/linking failures. Beyond these, whether additional warnings and so forth are generated is a matter of the implementation's discretion and quality. If the context isn't a debug context, then the implementation is free to provide fewer messages than debug contexts, or none at all. It may even swallow up user-generated messages. So messages are only guaranteed when using a debug context. Message Sources Source enum Generated by DEBUG_SOURCE_API Calls to
The recommended behavior in
Gl_context_flags
the case of an error is to glfw debug context output a message and exit. In the case of a warning, gl_context_flag_debug_bit the recommended behavior is to output a message and continue. All improper uses of the GLUT interface do not https://www.opengl.org/wiki/Debug_Output need to be caught or reported. What conditions are caught or reported should be based on how expensive the condition is to check for. For example, an implementation may not check every glutSetWindow call to determine if https://www.opengl.org/resources/libraries/glut/spec3/node98.html the window identifier is valid. The run-time overhead of error checking for a very common operation may outweight the benefit of clean error reporting. This trade-off is left for the implementor to make. The implementor should also consider the difficulty of diagnosing the improper usage without a message being output. For example, if a GLUT program attempts to create a menu while a menu is in use (improper usage!), this warrants a message because this improper usage may often be benign, allowing the bug to easily go unnoticed. Next: 14.4 Avoid Unspecified GLUT Up: 14 Implementation Issues Previous: 14.2 Modular Implementation Mark Kilgard Fri Feb 23 08:05:02 PST 1996
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company http://stackoverflow.com/questions/9125236/opengl-stopped-rendering Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 6.2 million programmers, http://www.vtk.org/Wiki/VTK/OpenGL_Errors just like you, helping each other. Join them; it only takes a minute: Sign up OpenGL stopped rendering up vote 0 down vote favorite First things first: Platform is Windows 7 64-bit, language is VC++, IDE opengl error is VS2010. Graphics card is nVidia GTX 460, drivers are version 290.53. So here's the situation. I am currently working in OpenGL using Glew 1.7 and Glut. I set everything up a few days ago and managed to successfully code and complete an assignment for my classes. The assignment ran beautifully and displayed and did everything it was supposed to. That was wonderful. So I submitted my assignment and didn't touch it again until opengl error reporting tonight. Now, tonight I tried running the code again and instead of my beautifully tessellated polygons I am getting a plain white window. As far as I know, nothing related to OpenGL has changed on my system since I last ran the code. I haven't changed the code at all, I haven't changed the graphics drivers, I haven't changed anything that I am aware of. I couldn't seem to find anything related to this kind of problem, and I am at a loss of what could possibly be causing the issue. I even tried recompiling Glew, but it didn't change anything. I know it's not a code issue since it was working fine a few days ago and nothing has changed, so it has to be a configuration issue. Could someone please point me in the right direction? Edit One more thing to add to this. When I was originally doing the project in question, attempting to run it produced the error message "unable to find glew32d.dll" until I placed glew32d.dll and glut32.dll in the source folder of my project. Now, I don't remember deleting them from my project folder, but when I tried to debug it last night, I noticed that both of them had disappeared from my project folder. However, I was not getting any .dll missing erro
this design it's important to check and clear the error flags regularly otherwise they can become unusable as code checking for errors ends up reporting earlier unrelated errors. In VTK 6.1 functions that make OpenGL calls have been instrumented with new OpenGL error management macros. A number of bugs that were detected by the new error checking and reporting have been fixed. Contents 1 Changes to the coding standard for VTK 6.1 and beyond 2 VTK OpenGL error management macros 3 Transitioning to VTK 6.1 3.1 Apple Mac OSX Changes to the coding standard for VTK 6.1 and beyond In VTK 6.1 and code introduce after the following policy is recommended. at public entry points into code that uses OpenGL clear the error flags without reporting errors. This guards against reporting unrelated errors, such as those caused by code outside of VTK. See vtkOpenGLClearErrorMacro before returning from functions that made OpenGL calls check for and report OpenGL errors. This detects Open GL errors in the function/method where they occurred facilitating debugging and it clears error flags so that user code doesn't detect errors caused by VTK. See vtkOpenGLCheckErrorMacro In summary: By calling vtkOpenGLClearErrorMacro at the top of a method that makes OpenGL calls, you isolate the code and prevent it from detecting any preceding errors. By calling vtkOpenGLCheckErrorMacro at the bottom of the method you clear the error flags and report any errors that have occurred in the method where they occurred. VTK OpenGL error management macros The following macros, which are found in vtkOpenGLError.h, can be used to detect and report, and/or silently clear OpenGL error flags. The intended usage pattern is to 1) call vtkOpenGLClearErrorMacro at the top of, and 2) vtkOpenGLCheckErrorMacro at the bottom of methods that make OpenGL calls. The macros maybe completely disabled via the CMakeLists variable VTK_REPORT_OPENGL_ERRORS. Note that in that case error flags are never cleared so that if an error occurs the flags will remain dirty making it impossible for anyone else to use them reliably. vtkOpenGLClearErrorMacro() Silently clear OpenGL error flags. vtkOpenGLCheckErrorMacro(message) Check and clear OpenGL's error flags. Report errors detected via vtkErrorMacro. vtkOpenGLStaticCheckErrorMacro(message) Check and clear OpenGL's error flags. Report errors detected via vtkGenericWarningMacro. This may be used in static methods and outside of vtkObjects. Transitioning to VTK 6.1 When transitioning existing code and a