nr-filter-gaussian.h revision a72861cd83f11ef8b1247abca181a3ad31df0307
#ifndef __NR_FILTER_GAUSSIAN_H__
#define __NR_FILTER_GAUSSIAN_H__
/*
* Gaussian blur renderer
*
* Author:
* Niko Kiirala <niko@kiirala.com>
*
* Copyright (C) 2006 Niko Kiirala
*
* Released under GNU GPL, read the file 'COPYING' for more information
*/
#include "display/nr-filter-primitive.h"
#include "libnr/nr-pixblock.h"
#include "libnr/nr-matrix.h"
namespace NR {
class FilterGaussian : public FilterPrimitive {
public:
FilterGaussian();
static FilterPrimitive *create();
virtual ~FilterGaussian();
virtual int render(NRPixBlock **pb, Matrix const &trans);
virtual int get_enlarge(Matrix const &m);
/**
* Set the standard deviation value for gaussian blur. Deviation along
* both axis is set to the provided value.
* Negative value, NaN and infinity are considered an error and no
* changes to filter state are made. If not set, default value of zero
* is used, which means the filter results in transparent black image.
*/
void set_deviation(double deviation);
/**
* Set the standard deviation value for gaussian blur. First parameter
* sets the deviation alogn x-axis, second along y-axis.
* Negative value, NaN and infinity are considered an error and no
* changes to filter state are made. If not set, default value of zero
* is used, which means the filter results in transparent black image.
*/
void set_deviation(double x, double y);
private:
double _deviation_x;
double _deviation_y;
int _kernel_size(Matrix const &trans);
void _make_kernel(double *kernel, double deviation, double expansion);
int _effect_area_scr_x(Matrix const &trans);
int _effect_area_scr_y(Matrix const &trans);
int _effect_subsample_step(int scr_len_x);
int _effect_subsample_step_log2(int scr_len_x);
inline int _min(int const a, int const b)
{
return ((a < b) ? a : b);
}
inline int _max(int const a, int const b)
{
return ((a > b) ? a : b);
}
};
} /* namespace NR */
#endif /* __NR_FILTER_GAUSSIAN_H__ */
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
indent-tabs-mode:nil
fill-column:99
End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :