GLGETHISTOGRAMPARAMETER

Section: Misc. Reference Manual Pages (3G)
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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.