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openglstencil-buffer

glStencilFunc(GL_NEVER, 0, 0) still renders?

I have problems utilizing the stencil buffer, and it's seems to boil down to not work at all. Given the following code:

  glEnable(GL_STENCIL_TEST);
  glClearStencil(0);
  glClear(GL_STENCIL_BUFFER_BIT | GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  glColor4f(1, 1, 1, 1);
  glStencilFuncSeparate(GL_FRONT_AND_BACK, GL_NEVER, 0, 0);
  glStencilOpSeparate(GL_FRONT_AND_BACK, GL_INCR, GL_INCR, GL_INCR);
  glBegin(GL_TRIANGLES);
  { draw something }
  glEnd();

The triangles are still drawn!? Am I missing something trivial here?

Note: I'm not rendering to a frame buffer, I'm using glStencil...Separate just to make sure it's not related to front\back, I've kept bits of code that to me doesn't seem related.

Solution

  • You don't have a stencil buffer. And by the specification (from 4.3 core, folio page 432):

    If there is no stencil buffer, no stencil modification can occur, and it is as if the stencil tests always pass, regardless of any calls to StencilFunc.