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glGetHistogramParameterfv, glGetHistogramParameteriv - get histogram
parameters 
 
void glGetHistogramParameterfv( GLenum target,
    GLenum pname,
    GLfloat *params )
void glGetHistogramParameteriv( GLenum target, 
    GLenum pname,
    GLint *params )
 
- 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. 
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 | 
 
 
glGetHistogramParameter
is present only if GL_ARB_imaging is returned when glGetString is called
with an argument of GL_EXTENSIONS. 
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. 
glGetHistogram(3G)
, glHistogram(3G)
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