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Name

glGetHistogramParameterfv, glGetHistogramParameteriv - get histogram

parameters

C Specification

void glGetHistogramParameterfv( GLenum target,
    GLenum pname,
    GLfloat *params )
void glGetHistogramParameteriv( GLenum target,
    GLenum pname,
    GLint *params )

Parameters

target
Must be one of GL_HISTOGRAM or GL_PROXY_HISTOGRAM.
pname
The name of the parameter to be retrieved. Must be one of GL_HISTOGRAM_WIDTH, GL_HISTOGRAM_FORMAT, GL_HISTOGRAM_RED_SIZE, GL_HISTOGRAM_GREEN_SIZE, GL_HISTOGRAM_BLUE_SIZE, GL_HISTOGRAM_ALPHA_SIZE, GL_HISTOGRAM_LUMINANCE_SIZE, or GL_HISTOGRAM_SINK.
params
Pointer to storage for the returned values.

Description

glGetHistogramParameter is used to query parameter values for the current histogram or for a proxy. The histogram state information may be queried by calling glGetHistogramParameter with a target of GL_HISTOGRAM (to obtain information for the current histogram table) or GL_PROXY_HISTOGRAM (to obtain information from the most recent proxy request) and one of the following values for the pname argument:

Parameter    Description
GL_HISTOGRAM_WIDTH    Histogram table width
GL_HISTOGRAM_FORMAT    Internal
GL_HISTOGRAM_RED_SIZE    Red component counter size, in bits
GL_HISTOGRAM_GREEN_SIZE    Green component counter size, in bits
Parameter    Description
GL_HISTOGRAM_BLUE_SIZE    Blue component counter size, in bits
GL_HISTOGRAM_ALPHA_SIZE    Alpha component counter size, in bits
GL_HISTOGRAM_LUMINANCE_SIZE    Luminance component counter size, in bits
GL_HISTOGRAM_SINK    Value of the sink parameter

Notes

glGetHistogramParameter is present only if GL_ARB_imaging is returned when glGetString is called with an argument of GL_EXTENSIONS.

Errors

GL_INVALID_ENUM is generated if target is not one of the allowable values.

GL_INVALID_ENUM is generated if pname is not one of the allowable values.

GL_INVALID_OPERATION is generated if glGetHistogramParameter is executed between the execution of glBegin and the corresponding execution of glEnd.

See Also

glGetHistogram(3G) , glHistogram(3G)


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