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#define __SP_FILTER_CHEMISTRY_C__
/*
* Various utility methods for filters
*
* Authors:
* Hugo Rodrigues
* bulia byak
*
* Copyright (C) 2006 authors
*
* Released under GNU GPL, read the file 'COPYING' for more information
*/
#include "style.h"
#include "document-private.h"
#include "desktop-style.h"
#include "sp-filter.h"
#include "sp-gaussian-blur.h"
#include "svg/css-ostringstream.h"
#include "xml/repr.h"
/**
* Creates a filter with blur primitive of specified radius for an item with the given matrix expansion, width and height
*/
SPFilter *
new_filter_gaussian_blur (SPDocument *document, gdouble radius, double expansion, double expansionX, double expansionY, double width, double height)
{
g_return_val_if_fail(document != NULL, NULL);
SPDefs *defs = (SPDefs *) SP_DOCUMENT_DEFS(document);
Inkscape::XML::Document *xml_doc = sp_document_repr_doc(document);
// create a new filter
Inkscape::XML::Node *repr;
repr = xml_doc->createElement("svg:filter");
repr->setAttribute("inkscape:collect", "always");
double rx = radius * (expansionY != 0? (expansion / expansionY) : 1);
double ry = radius * (expansionX != 0? (expansion / expansionX) : 1);
if (width != 0 && height != 0 && (2.4 * rx > width * 0.1 || 2.4 * ry > height * 0.1)) {
// If not within the default 10% margin (see
// http://www.w3.org/TR/SVG11/filters.html#FilterEffectsRegion), specify margins
// The 2.4 is an empirical coefficient: at that distance the cutoff is practically invisible
// (the opacity at 2.4*radius is about 3e-3)
double xmargin = 2.4 * (rx) / width;
double ymargin = 2.4 * (ry) / height;
// TODO: set it in UserSpaceOnUse instead?
sp_repr_set_svg_double(repr, "x", -xmargin);
sp_repr_set_svg_double(repr, "width", 1 + 2 * xmargin);
sp_repr_set_svg_double(repr, "y", -ymargin);
sp_repr_set_svg_double(repr, "height", 1 + 2 * ymargin);
}
//create feGaussianBlur node
Inkscape::XML::Node *b_repr;
b_repr = xml_doc->createElement("svg:feGaussianBlur");
b_repr->setAttribute("inkscape:collect", "always");
double stdDeviation = radius;
if (expansion != 0)
stdDeviation /= expansion;
//set stdDeviation attribute
sp_repr_set_svg_double(b_repr, "stdDeviation", stdDeviation);
//set feGaussianBlur as child of filter node
repr->appendChild(b_repr);
Inkscape::GC::release(b_repr);
// Append the new filter node to defs
SP_OBJECT_REPR(defs)->appendChild(repr);
Inkscape::GC::release(repr);
// get corresponding object
SPFilter *f = SP_FILTER( document->getObjectByRepr(repr) );
SPGaussianBlur *b = SP_GAUSSIANBLUR( document->getObjectByRepr(b_repr) );
g_assert(f != NULL);
g_assert(SP_IS_FILTER(f));
g_assert(b != NULL);
g_assert(SP_IS_GAUSSIANBLUR(b));
return f;
}
/**
* Creates a filter with blur primitive of specified radius for the given item
*/
SPFilter *
new_filter_gaussian_blur_from_item (SPDocument *document, SPItem *item, gdouble radius)
{
NR::Maybe<NR::Rect> const r = sp_item_bbox_desktop(item);
double width;
double height;
if (r) {
width = r->extent(NR::X);
height= r->extent(NR::Y);
} else {
width = height = 0;
}
NR::Matrix i2d = sp_item_i2d_affine (item);
return (new_filter_gaussian_blur (document, radius, i2d.expansion(), i2d.expansionX(), i2d.expansionY(), width, height));
}
void remove_filter (SPObject *item, bool recursive)
{
SPCSSAttr *css = sp_repr_css_attr_new ();
sp_repr_css_unset_property (css, "filter");
if (recursive)
sp_repr_css_change_recursive(SP_OBJECT_REPR(item), css, "style");
else
sp_repr_css_change (SP_OBJECT_REPR(item), css, "style");
sp_repr_css_attr_unref (css);
}
/*
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 :
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