GLPOINTPARAMETER(3G)

NAME
glPointParameter - specify point parameters

C SPECIFICATION

void glPointParameterf(GLenum pname, GLfloat param);

void glPointParameteri(GLenum pname, GLint param);

PARAMETERS

pname
    Specifies a single-valued point parameter. GL_POINT_SIZE_MIN, GL_POINT_SIZE_MAX, GL_POINT_FADE_THRESHOLD_SIZE, and GL_POINT_SPRITE_COORD_ORIGIN are accepted.

param
    Specifies the value that pname will be set to.

C SPECIFICATION

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

void glPointParameteriv(GLenum pname, const GLint * params);

PARAMETERS

pname
    Specifies a point parameter. GL_POINT_SIZE_MIN, GL_POINT_SIZE_MAX, GL_POINT_DISTANCE_ATTENUATION, GL_POINT_FADE_THRESHOLD_SIZE, and GL_POINT_SPRITE_COORD_ORIGIN are accepted.

params
    Specifies the value or values to be assigned to pname. GL_POINT_DISTANCE_ATTENUATION requires an array of three values. All other parameters accept an array containing only a single value.

DESCRIPTION

The following values are accepted for pname:

GL_POINT_SIZE_MIN

    params is a single floating-point value that specifies the minimum point size. The default value is 0.0.

GL_POINT_SIZE_MAX

    params is a single floating-point value that specifies the maximum point size. The default value is 1.0.

GL_POINT_FADE_THRESHOLD_SIZE

    params is a single floating-point value that specifies the threshold value to which point sizes are clamped if they exceed the specified value. The default value is 1.0.

GL_POINT_DISTANCE_ATTENUATION

    params is an array of three floating-point values that specify the coefficients used for scaling the computed point size. The default values are 1 0 0.

GL_POINT_SPRITE_COORD_ORIGIN

    params is a single enum specifying the point sprite texture coordinate origin, either GL_LOWER_LEFT or GL_UPPER_LEFT. The default value is GL_UPPER_LEFT.

NOTES

glPointParameter is available only if the GL version is 1.4 or greater.

GL_POINT_SPRITE_COORD_ORIGIN is available only if the GL version is 2.0 or greater.

ERRORS

GL_INVALID_VALUE is generated If the value specified for GL_POINT_SIZE_MIN, GL_POINT_SIZE_MAX, or GL_POINT_FADE_THRESHOLD_SIZE is less than zero.

GL_INVALID_ENUM is generated If the value specified for GL_POINT_SPRITE_COORD_ORIGIN is not GL_LOWER_LEFT or GL_UPPER_LEFT.

If the value for GL_POINT_SIZE_MIN is greater than GL_POINT_SIZE_MAX, the point size after clamping is undefined, but no error is generated.

ASSOCIATED GETS

glGet() with argument GL_POINT_SIZE_MIN

glGet() with argument GL_POINT_SIZE_MAX

glGet() with argument GL_POINT_FADE_THRESHOLD_SIZE

glGet() with argument GL_POINT_DISTANCE_ATTENUATION

glGet() with argument GL_POINT_SPRITE_COORD_ORIGIN

SEE ALSO

glPointSize()

COPYRIGHT

Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.