glLightEnv(3G)

NAME
     glLightEnviSGIX - specify fragment lighting environment


C SPECIFICATION
     void glLightEnviSGIX( GLenum pname,
                           GLint param )


PARAMETERS
     pname  Must be GL_LIGHT_ENV_MODE_SGIX

     param  Can be one of three values: GL_REPLACE, GL_MODULATE, or GL_ADD

DESCRIPTION
     GL_LIGHT_ENV_MODE_SGIX specifies how the color computed by fragment
     lighting calculations is combined with the post-texturing fragment color.

     GL_REPLACE          The lighting color replaces the fragment color

     GL_MODULATE         Each (R,G,B,A) component of the fragment color is
                         multiplied by the corresponding component of the
                         lighting color

     GL_ADD              The lighting color is added to the fragment color

     Initially GL_LIGHT_ENV_MODE_SGIX is set to GL_REPLACE.

NOTES
     glLightEnv is part of the GL_SGIX_fragment_lighting extension. glLightEnv
     is present only if GL_SGIX_fragment_lighting is returned when glGetString
     is called with GL_EXTENSIONS as its argument.

ERRORS
     GL_INVALID_OPERATION is generated if glLightEnv is executed between the
     execution of glBegin and the corresponding execution of glEnd.
     GL_INVALID_ENUM is generated if pname is not GL_LIGHT_ENV_MODE_SGIX, or
     param is not one of GL_REPLACE, GL_MODULATE, or GL_ADD.

ASSOCIATED GETS
     glGet with an argument of GL_LIGHT_ENV_MODE_SGIX


MACHINE DEPENDENCIES
     The SGIX_fragment_lighting extension is supported only on Octane2 VPro
     systems.


SEE ALSO
     glGetString, glFragmentLight