I am using OpenGL version 3.0 and I want to test the transformfeedback feature.
I’ve write a app and doing it by
- calling glTransformFeedback varyings() before vertex shader linking.
- Binding trasform feedback buffer
- calling beginquery with GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN
- gl drawarrays
At the end query object is returning a 0 primitives written.
If I query with the PRIMITIVE_GENERATED than it is giving me proper value but not sure why it is not retuning any primitive to TRANSFORM_FEEDBACK_BUFFER?
Moreover, I am able to see the display on screen. So data is in a framebuffer.
Could anyone tell me, how to get transform feedback buffer?