Name

glPointParameter — specify parameters for point rasterization

C Specification

void glPointParameterf(GLenum pname,
 GLfloat param);
 
void glPointParameterx(GLenum pname,
 GLfixed param);
 

Parameters

pname

Specifies the single-valued parameter to be updated. Can be either GL_POINT_SIZE_MIN, GL_POINT_SIZE_MAX, or GL_POINT_FADE_THRESHOLD_SIZE.

param

Specifies the value that the parameter will be set to.

C Specification

void glPointParameterfv(GLenum pname,
 const GLfloat * params);
 
void glPointParameterxv(GLenum pname,
 const GLfixed * params);
 

Parameters

pname

Specifies the parameter to be updated. Can be either GL_POINT_SIZE_MIN, GL_POINT_SIZE_MAX, GL_POINT_FADE_THRESHOLD_SIZE, or GL_POINT_DISTANCE_ATTENUATION.

params

Specifies a pointer to the value or values that pname will be set to.

Description

glPointParameter assigns values to point parameters.

glPointParameter takes two arguments. pname, specifies which of several parameters will be modified. params, specifies what value or values will be assigned to the specified parameter.

The parameters that can be specified using glPointParameter, and their interpretations are as follows:

GL_POINT_SIZE_MIN

param specifies, or params points to the lower bound to which the derived point size is clamped.

GL_POINT_SIZE_MAX

param specifies, or params points to the upper bound to which the derived point size is clamped.

GL_POINT_FADE_THRESHOLD_SIZE

param specifies, or params points to the point fade threshold.

GL_POINT_DISTANCE_ATTENUATION

params points to the distance attenuation function coefficients a, b, and c.

Notes

If the point size lower bound is greater than the upper bound, then the point size after clamping is undefined.

Errors

GL_INVALID_ENUM is generated if pname is not an accepted value.

GL_INVALID_VALUE is generated if assigned values for GL_POINT_SIZE_MIN, GL_POINT_SIZE_MAX, or GL_POINT_FADE_THRESHOLD_SIZE are less then zero.

Associated Gets

glGet with argument GL_POINT_DISTANCE_ATTENUATION

glGet with argument GL_POINT_FADE_THRESHOLD_SIZE

glGet with argument GL_POINT_SIZE_MAX

glGet with argument GL_POINT_SIZE_MIN

See Also

glEnable, glGet, glLight, glLightModel

Copyright

Copyright © 2003-2004 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.