1 #define __SP_FILTER_CHEMISTRY_C__
3 /*
4 * Various utility methods for filters
5 *
6 * Authors:
7 * Hugo Rodrigues
8 * bulia byak
9 *
10 * Copyright (C) 2006 authors
11 *
12 * Released under GNU GPL, read the file 'COPYING' for more information
13 */
16 #include "style.h"
17 #include "document-private.h"
18 #include "desktop-style.h"
20 #include "sp-filter.h"
21 #include "sp-gaussian-blur.h"
22 #include "svg/css-ostringstream.h"
24 #include "xml/repr.h"
26 /**
27 * Creates a filter with blur primitive of specified radius for an item with the given matrix expansion, width and height
28 */
29 SPFilter *
30 new_filter_gaussian_blur (SPDocument *document, gdouble radius, double expansion, double expansionX, double expansionY, double width, double height)
31 {
32 g_return_val_if_fail(document != NULL, NULL);
34 SPDefs *defs = (SPDefs *) SP_DOCUMENT_DEFS(document);
36 Inkscape::XML::Document *xml_doc = sp_document_repr_doc(document);
38 // create a new filter
39 Inkscape::XML::Node *repr;
40 repr = xml_doc->createElement("svg:filter");
41 repr->setAttribute("inkscape:collect", "always");
43 double rx = radius * (expansionY != 0? (expansion / expansionY) : 1);
44 double ry = radius * (expansionX != 0? (expansion / expansionX) : 1);
46 if (width != 0 && height != 0 && (2.4 * rx > width * 0.1 || 2.4 * ry > height * 0.1)) {
47 // If not within the default 10% margin (see
48 // http://www.w3.org/TR/SVG11/filters.html#FilterEffectsRegion), specify margins
49 // The 2.4 is an empirical coefficient: at that distance the cutoff is practically invisible
50 // (the opacity at 2.4*radius is about 3e-3)
51 double xmargin = 2.4 * (rx) / width;
52 double ymargin = 2.4 * (ry) / height;
54 // TODO: set it in UserSpaceOnUse instead?
55 sp_repr_set_svg_double(repr, "x", -xmargin);
56 sp_repr_set_svg_double(repr, "width", 1 + 2 * xmargin);
57 sp_repr_set_svg_double(repr, "y", -ymargin);
58 sp_repr_set_svg_double(repr, "height", 1 + 2 * ymargin);
59 }
61 //create feGaussianBlur node
62 Inkscape::XML::Node *b_repr;
63 b_repr = xml_doc->createElement("svg:feGaussianBlur");
64 b_repr->setAttribute("inkscape:collect", "always");
66 double stdDeviation = radius;
67 if (expansion != 0)
68 stdDeviation /= expansion;
70 //set stdDeviation attribute
71 sp_repr_set_svg_double(b_repr, "stdDeviation", stdDeviation);
73 //set feGaussianBlur as child of filter node
74 repr->appendChild(b_repr);
75 Inkscape::GC::release(b_repr);
77 // Append the new filter node to defs
78 SP_OBJECT_REPR(defs)->appendChild(repr);
79 Inkscape::GC::release(repr);
81 // get corresponding object
82 SPFilter *f = SP_FILTER( document->getObjectByRepr(repr) );
83 SPGaussianBlur *b = SP_GAUSSIANBLUR( document->getObjectByRepr(b_repr) );
85 g_assert(f != NULL);
86 g_assert(SP_IS_FILTER(f));
87 g_assert(b != NULL);
88 g_assert(SP_IS_GAUSSIANBLUR(b));
90 return f;
91 }
93 /**
94 * Creates a filter with blur primitive of specified radius for the given item
95 */
96 SPFilter *
97 new_filter_gaussian_blur_from_item (SPDocument *document, SPItem *item, gdouble radius)
98 {
99 NR::Maybe<NR::Rect> const r = sp_item_bbox_desktop(item);
101 double width;
102 double height;
103 if (r) {
104 width = r->extent(NR::X);
105 height= r->extent(NR::Y);
106 } else {
107 width = height = 0;
108 }
110 NR::Matrix i2d = sp_item_i2d_affine (item);
112 return (new_filter_gaussian_blur (document, radius, i2d.expansion(), i2d.expansionX(), i2d.expansionY(), width, height));
113 }
115 void remove_filter (SPObject *item, bool recursive)
116 {
117 SPCSSAttr *css = sp_repr_css_attr_new ();
118 sp_repr_css_unset_property (css, "filter");
119 if (recursive)
120 sp_repr_css_change_recursive(SP_OBJECT_REPR(item), css, "style");
121 else
122 sp_repr_css_change (SP_OBJECT_REPR(item), css, "style");
123 sp_repr_css_attr_unref (css);
124 }
126 /*
127 Local Variables:
128 mode:c++
129 c-file-style:"stroustrup"
130 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
131 indent-tabs-mode:nil
132 fill-column:99
133 End:
134 */
135 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :