glPointParameter — specify point parameters
void glPointParameterf( | GLenum | pname, |
GLfloat | param) ; |
void glPointParameteri( | GLenum | pname, |
GLint | param) ; |
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.
void glPointParameterfv( | GLenum | pname, |
const GLfloat * | params) ; |
void glPointParameteriv( | GLenum | pname, |
const GLint * | params) ; |
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.
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
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
.
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.
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.
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
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