GLRENDERMODE(3G)														  GLRENDERMODE(3G)

NAME

       glRenderMode - set rasterization mode

C SPECIFICATION

       GLint glRenderMode( GLenum mode )

PARAMETERS

       mode  Specifies the rasterization mode.	Three values are accepted: GL_RENDER, GL_SELECT, and GL_FEEDBACK.  The initial value is GL_RENDER.

DESCRIPTION

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

       GL_RENDER       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.

       GL_SELECT       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 GL_RENDER is returned in a select buffer,
		       which must be created (see glSelectBuffer) before selection mode is entered.

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

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

       GL_RENDER       0.

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

       GL_FEEDBACK     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, glRenderMode returns 0 regardless of the current render mode.

ERRORS

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

       GL_INVALID_OPERATION  is  generated if glSelectBuffer is called while the render mode is GL_SELECT, or if glRenderMode is called with argu-
       ment GL_SELECT before glSelectBuffer is called at least once.

       GL_INVALID_OPERATION is generated if glFeedbackBuffer is called while the render mode is GL_FEEDBACK, or if  glRenderMode  is  called  with
       argument GL_FEEDBACK before glFeedbackBuffer is called at least once.

       GL_INVALID_OPERATION is generated if glRenderMode is executed between the execution of glBegin and the corresponding execution of glEnd.

ASSOCIATED GETS

       glGet with argument GL_RENDER_MODE

SEE ALSO

       glFeedbackBuffer, glInitNames, glLoadName, glPassThrough, glPushName, glSelectBuffer

																  GLRENDERMODE(3G)