Baffling GL error

Sage

Posts: 1,199
Joined: 2004.10

Post: #1

Apr 14, 2005 — 04:33 AM

I've been trying to track down an error state in my game engine, so I told OpenGL Profiler to break on error.

So, the odd thing is that I'm getting an error for glGenLists.

Code:

glGenLists() 

    Error: GL_INVALID_VALUE

    Context: <not available>

Function call stack: 

    0: gloTerminateLibrary <GLProfiler> 

    1: gloGetCGLDispatch <GLProfiler> 

    2: Mesh::Geometry::draw() <Legion> /Users/zakariya/Projects/Legion/src/Core/Mesh/Mesh.cpp: 314 

    3: Mesh::Entity::draw() <Legion> /Users/zakariya/Projects/Legion/src/Core/Mesh/Mesh.cpp: 865 

    4: Legion::ColonyPart::display(float) <Legion> /Users/zakariya/Projects/Legion/src/Core/Environment/Colony.cpp: 558 

    5: Legion::SceneNode::display(float) <Legion> /Users/zakariya/Projects/Legion/src/Core/SceneGraph.cpp: 433 

    6: Legion::SceneGraph::display(float) <Legion> /Users/zakariya/Projects/Legion/src/Core/SceneGraph.cpp: 792 

    7: Legion::Stage::displayLit(float) <Legion> /Users/zakariya/Projects/Legion/src/Core/Stage.cpp: 742 

    8: Legion::Stage::display(float) <Legion> /Users/zakariya/Projects/Legion/src/Core/Stage.cpp: 711 

    9: Legion::LegionGame::displayStage(float) <Legion> /Users/zakariya/Projects/Legion/src/Legion/LegionGame.cpp: 392 

    10: Legion::DecalTestState::display(float) <Legion> /Users/zakariya/Projects/Legion/src/Legion/States/Tests/DecalTestState.cpp: 76 

    11: Legion::GameWorld::display(float) <Legion> /Users/zakariya/Projects/Legion/src/Core/GameWorld.cpp: 141 

    12: Legion::LegionGame::display(float) <Legion> /Users/zakariya/Projects/Legion/src/Legion/LegionGame.cpp: 154 

    13: GSEventDisplay <Legion> /Users/zakariya/Projects/Legion/src/GameShell/GSEvents.mm: 80 

    14: -[GSOpenGLView drawRect:] <Legion> /Users/zakariya/Projects/Legion/src/GameShell/GSOpenGLView.m: 128 

    15: 0x92dc7c2c 

    16: 0x92dd8670 

    17: 0x92e0e3d0 

    18: 0x9019f16c 

    19: 0x92dd8774 

    20: 0x92dc3f44 

    21: 0x92dc4360 

    22: 0x92e10ef0 

    23: 0x92df808c 

    24: 0x92dd5244 

    25: 0x92dee274 

    26: 0x909f30e4 

    27: 0x901945f8 

    28: 0x90191958 

    29: 0x90195e6c 

    30: 0x927d5f60 

    31: 0x927dc6c8 

    32: 0x927fe6a0 

    33: 0x92dd2e44 

    34: 0x92de98c8 

    35: 0x92dfdc30 

    36: 0x92eba2b8 

    37: main <Legion> /Users/zakariya/Projects/Legion/src/main.m: 13 

    38: _start <Legion> /SourceCache/Csu/Csu-47/crt.c: 267 

    39: _dyld_start <dyld>

This doesn't make any sense to me. The actual code is this:

Code:

void Geometry::draw( void )

{

    if ( _immediateMode )

    {

        _draw();

    }

    else

    {

        if ( !_dListID )

        {

            _dListID = glGenLists(1); // <-- glError here

            glNewList( _dListID, GL_COMPILE );

            _draw();

            glEndList();

        }

        glCallList( _dListID );

    }    

}

Now, printf'ing the value of _dListID I see what looks like a valid display list name. Also, according to the manpage, glGenLists should only create the invalid value error state if the passed in number of names is less than zero.

According to the manpage:

Code:

GL_INVALID_VALUE is generated if range is negative.

GL_INVALID_OPERATION is generated if glGenLists is executed between the execution of glBegin and the corresponding execution of glEnd.

As far as I can tell, this is the *first* error state, since GL Profiler lets the program run happily up to this point. That is to say, game menus, progress loading indicators, etc all draw fine. It breaks on the first drawing frame of the actual game, when I create the display list.

Also, it should be said that the game *runs* fine, so long as I'm not breaking on GL Error. And, one more thing, I'm using glew ( glew.sf.net ) to manage GL extensions.

Any ideas?