GLRENDERMODE(3G)                                              GLRENDERMODE(3G)



NAME
       glRenderode - set rasterization mode


C SPECIFICATION
       GLint glRenderode( GLenum mode )


PARAMETERS
       mode  Specifies  the  rasterization  mode.   Three values are accepted:
             GLRENDER, GLSELECT, and  GLFEDBACK.   The  initial  value  is
             GLRENDER.

DESCRIPTION
       glRenderode sets the rasterization mode.  It takes one argument, mode,
       which can assume one of three predefined values:

       GLRENDER       Render mode. Primitives are rasterized, producing pixel
                       fragments,  which  are  written  into the frame buffer.
                       This is the normal mode and also the default mode.

       GLSELECT       Selection mode.  No pixel fragments are  produced,  and
                       no  change  to  the  frame  buffer  contents  is  made.
                       Instead, a record of the names of primitives that would
                       have  been  drawn if the render mode had been GLRENDER
                       is returned in a select buffer, which must  be  created
                       (see  glSelectBuffer) before selection mode is entered.

       GLFEDBACK     Feedback mode.  No pixel fragments are produced, and no
                       change  to the frame buffer contents is made.  Instead,
                       the coordinates and attributes of vertices  that  would
                       have  been  drawn if the render mode had been GLRENDER
                       is returned in a feedback buffer, which must be created
                       (see glFeedbackBuffer) before feedback mode is entered.

       The return value of glRenderode is determined by the  render  mode  at
       the  time  glRenderode  is  called,  rather  than by mode.  The values
       returned for the three render modes are as follows:

       GLRENDER       0.

       GLSELECT       The number of hit records  transferred  to  the  select
                       buffer.

       GLFEDBACK     The  number of values (not vertices) transferred to the
                       feedback buffer.

       See the glSelectBuffer and glFeedbackBuffer reference  pages  for  more
       details concerning selection and feedback operation.

NOTES
       If an error is generated, glRenderode returns 0 regardless of the cur-
       rent render mode.

ERORS
       GLINVALIDENUM is generated if mode is not one of the  three  accepted
       values.

       GLINVALIDOPERATION is generated if glSelectBuffer is called while the
       render mode is GLSELECT, or if glRenderode is  called  with  argument
       GLSELECT before glSelectBuffer is called at least once.

       GLINVALIDOPERATION  is  generated if glFeedbackBuffer is called while
       the render mode is GLFEDBACK, or if glRenderode is called with argu-
       ment GLFEDBACK before glFeedbackBuffer is called at least once.

       GLINVALIDOPERATION  is  generated if glRenderode is executed between
       the execution of glBegin and the corresponding execution of glEnd.

ASOCIATED GETS
       glGet with argument GLRENDERMODE

SEE ALSO
       glFeedbackBuffer, glInitNames, glLoadName,  glPassThrough,  glPushName,
       glSelectBuffer



                                                              GLRENDERMODE(3G)