def _get_depthbuffer_texture(self):

        width, height = self.draw_obj.drawing_mgr.region.width, self.draw_obj.drawing_mgr.region.height

        texture_id_buf = Buffer(GL_INT, 1)
        fbo = Buffer(GL_INT, 1)

        glActiveTexture(GL_TEXTURE0)
        glGenTextures(1, texture_id_buf)

        glBindTexture(GL_TEXTURE_2D, texture_id_buf.to_list()[0])

        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE)
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE)
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST)
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST)

        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE, GL_COMPARE_REF_TO_TEXTURE)
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_FUNC, GL_LEQUAL)

        glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT24, width, height, 0, GL_DEPTH_COMPONENT, GL_FLOAT, 0)

        glGenFramebuffers(1, fbo)
        glBindFramebuffer(GL_FRAMEBUFFER, fbo.to_list()[0])

        glFramebufferTexture(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, texture_id_buf.to_list()[0], 0)

        glDrawBuffer(GL_NONE)

        glCheckError('draw')

        glReadBuffer(GL_NONE)

        fbo_status = glCheckFramebufferStatus(GL_FRAMEBUFFER)
        if fbo_status != GL_FRAMEBUFFER_COMPLETE:
            raise Exception("GL_FRAMEBUFFER_COMPLETE failed, CANNOT use FBO\n")

        glBindFramebuffer(GL_FRAMEBUFFER, 0)
        glBindTexture(GL_TEXTURE_2D, 0)

        glDisable(GL_TEXTURE_2D)
        glBindTexture(GL_TEXTURE_2D, 0)
        glBindFramebuffer(GL_FRAMEBUFFER, fbo.to_list()[0])

        glClear(GL_DEPTH_BUFFER_BIT)
        glColorMask(False, False, False, False)
        glCullFace(GL_BACK)

        glEnable(GL_TEXTURE_2D)
        glBindTexture(GL_TEXTURE_2D, texture_id_buf.to_list()[0])
        glBindFramebuffer(GL_FRAMEBUFFER, 0)
        glColorMask(True, True, True, True)

        return texture_id_buf.to_list()[0]