glDebugMessageCallback more detailed information

Question

Everywhere I read that glDebugMessageCallback is the better solution to get errors, so I implemented it. So far so good. And I am getting indeed more detailed information about what's going on. Currently on NVIDIA it looks f.e. like this:

DebugLog: In source API, type OTHER, id 131185, severity : NONE, message Buffer detailed info: Buffer object 3 (bound to GL_VERTEX_ATTRIB_ARRAY_BUFFER_BINDING_ARB (0), and GL_ARRAY_BUFFER_ARB, usage hint is GL_STREAM_DRAW) will use VIDEO memory as the source for buffer object operations.

Really nice, indeed- however, I miss one thing- I can't indicate here where exactly this happened.

If I use old style method with a macro like this:

#define CHECK_GL_ERROR() CheckGLError(__FILE__, __LINE__) and glGetError()

it's far less detailed and a mess in the code- BUT! I can track it more easily down to the line or call it happened, at least when debugging myself.

Of course, if I reduce the log level to something more severe, it is probably also easier to identify the origin, since there are less functions in question, yet, depending on code I find this a bit imprecise to find a specific function.

So my question is now- is there a way to tell what exactly the callback triggered, the function or the perhaps the line in the code, like in the old method (that is, now without adding a manual breakpoint/debug)??

I would find that very handy, especially when considering a situation in which someone who is maybe just using the software could provide me a log only for a problem I can't reproduce myself.

PS: Could someone enlighten me what "id" is for? I found a lot of tutorials and explanations, also read the docs but I still don't see of what use it is for debugging.

Answer 1

There are two ways that help you identify where the error comes from:

First, you can glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS) to ensure that errors are thrown in the scope of the function that produces them. When you now set a breakpoint in the error callback function, you'll see through the callstack where the error originates.

Second: OpenGL allows you to associate names and scopes with each OpenGL object. This allows you to specify names for, let's say, a buffer. Have a look here for more details.