1991-2006
Silicon Graphics, Inc.
glPointParameter
3G

# 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/.