Name

glGetConvolutionParameter — get convolution parameters

C Specification

void glGetConvolutionParameterfv(GLenum target,
 GLenum pname,
 GLfloat * params);
 
void glGetConvolutionParameteriv(GLenum target,
 GLenum pname,
 GLint * params);
 

Parameters

target

The filter whose parameters are to be retrieved. Must be one of GL_CONVOLUTION_1D, GL_CONVOLUTION_2D, or GL_SEPARABLE_2D.

pname

The parameter to be retrieved. Must be one of GL_CONVOLUTION_BORDER_MODE, GL_CONVOLUTION_BORDER_COLOR, GL_CONVOLUTION_FILTER_SCALE, GL_CONVOLUTION_FILTER_BIAS, GL_CONVOLUTION_FORMAT, GL_CONVOLUTION_WIDTH, GL_CONVOLUTION_HEIGHT, GL_MAX_CONVOLUTION_WIDTH, or GL_MAX_CONVOLUTION_HEIGHT.

params

Pointer to storage for the parameters to be retrieved.

Description

glGetConvolutionParameter retrieves convolution parameters. target determines which convolution filter is queried. pname determines which parameter is returned:

GL_CONVOLUTION_BORDER_MODE

The convolution border mode. See glConvolutionParameter for a list of border modes.

GL_CONVOLUTION_BORDER_COLOR

The current convolution border color. params must be a pointer to an array of four elements, which will receive the red, green, blue, and alpha border colors.

GL_CONVOLUTION_FILTER_SCALE

The current filter scale factors. params must be a pointer to an array of four elements, which will receive the red, green, blue, and alpha filter scale factors in that order.

GL_CONVOLUTION_FILTER_BIAS

The current filter bias factors. params must be a pointer to an array of four elements, which will receive the red, green, blue, and alpha filter bias terms in that order.

GL_CONVOLUTION_FORMAT

The current internal format. See glConvolutionFilter1D, glConvolutionFilter2D, and glSeparableFilter2D for lists of allowable formats.

GL_CONVOLUTION_WIDTH

The current filter image width.

GL_CONVOLUTION_HEIGHT

The current filter image height.

GL_MAX_CONVOLUTION_WIDTH

The maximum acceptable filter image width.

GL_MAX_CONVOLUTION_HEIGHT

The maximum acceptable filter image height.

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_ENUM is generated if target is GL_CONVOLUTION_1D and pname is GL_CONVOLUTION_HEIGHT or GL_MAX_CONVOLUTION_HEIGHT.

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

See Also

glGetConvolutionFilter, glGetSeparableFilter, glConvolutionParameter

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/.