Posted by stepasite on Jan 29, 2013; 1:12pm
URL: https://forum.jogamp.org/glReadBuffer-behavior-on-MAC-tp4028039.html

Hi,

after migration to JOGL2, I have problem when getting/setting value for read buffer on MAC OS X (no problems on Windows).

The code:

   int[] glReadBufferValue = new int[1];
   gl.glGetIntegerv(GL2.GL_READ_BUFFER, glReadBufferValue, 0);

sets GL.GL_COLOR_ATTACHMENT0 value into glReadBufferValue[0]. Strange as I do not use FBOs at all.

Furthermore, when trying set:

gl.getGL2().glReadBuffer(GL.GL_FRONT);

or

gl.getGL2().glReadBuffer(GL.GL_BACK);

I get GL_INVALID_OPERATION error.

Why does this happen? Is FBO used by JOGL2 internally for rendering? Is it possible that GL_FRONT, GL_BACK, etc. constants are not valid for some OpenGL implementations?

Any help would be much appreciated.

Thanks in advance,
Pavel

ps: os OS X 10.7.5, renderer: Intel GMA 950 OpenGL Engine