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bjornblissing / osgoculusviewer

An OsgViewer with support for the Oculus Rift
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Console outputs OpenGL errors in direct mode #36

Closed bjornblissing closed 9 years ago

bjornblissing commented 9 years ago

The console window outputs OpenGL errors when running in OculusViewConfigExample and OculusViewerExample (OculusCompositeViewerExample works without errors).

Warning: detected OpenGL error 'invalid operation' at after RenderBin::draw(..)

bjornblissing commented 9 years ago

Enabled OpenGL debugging in OpenSceneGraph by setting the environment variable:

OSG_GL_ERROR_CHECKING=ON

This gave the more detailed error message:

Warning: detected OpenGL error 'invalid operation' after applying attribute Viewport

But deeper debugging showed that the glGetError flag was not cleared before reaching this point inside OpenSceneGraph.

So I was forced to fence all OpenGL calls that was close to the error location with glGetError calls. This revealed that the causing calls were calls to glDrawBuffer and glReadBuffer. These must be disabled for the RTT cameras when using direct mode rendering.