c1012475c3bdb3bb2e715e616e1332422a3e98c4
1 #ifndef __NR_FILTER_H__
2 #define __NR_FILTER_H__
4 /*
5 * SVG filters rendering
6 *
7 * Author:
8 * Niko Kiirala <niko@kiirala.com>
9 *
10 * Copyright (C) 2006 Niko Kiirala
11 *
12 * Released under GNU GPL, read the file 'COPYING' for more information
13 */
15 //#include "display/nr-arena-item.h"
16 #include "display/nr-filter-primitive.h"
17 #include "display/nr-filter-types.h"
18 #include "libnr/nr-pixblock.h"
19 #include "libnr/nr-matrix.h"
20 #include "libnr/nr-rect.h"
21 #include "svg/svg-length.h"
22 #include "sp-filter-units.h"
23 #include "gc-managed.h"
25 struct NRArenaItem;
27 namespace NR {
29 class Filter : public Inkscape::GC::Managed<> {
30 public:
31 int render(NRArenaItem const *item, NRPixBlock *pb);
33 /**
34 * Creates a new filter primitive under this filter object.
35 * New primitive is placed so that it will be executed after all filter
36 * primitives defined beforehand for this filter object.
37 * Should this filter not have enough space for a new primitive, the filter
38 * is enlarged to accomodate the new filter element. It may be enlarged by
39 * more that one element.
40 * Returns a pointer to the filter primitive created.
41 * Returns NULL, if type is not valid filter primitive type or filter
42 * primitive of such type cannot be created.
43 */
44 FilterPrimitive *add_primitive(FilterPrimitiveType type);
45 /**
46 * Removes all filter primitives from this filter.
47 * All pointers to filter primitives inside this filter should be
48 * considered invalid after calling this function.
49 */
50 void clear_primitives();
51 /**
52 * Replaces filter primitive pointed by 'target' with a new filter
53 * primitive of type 'type'
54 * If 'target' does not correspond to any primitive inside this filter OR
55 * 'type' is not a valid filter primitive type OR
56 * filter primitive of such type cannot be created,
57 * this function returns NULL and doesn't change the internal state of this
58 * filter.
59 * Otherwise, a new filter primitive is created. Any pointers to filter
60 * primitive 'target' should be considered invalid. A pointer to the
61 * newly created primitive is returned.
62 */
63 FilterPrimitive *replace_primitive(FilterPrimitive *primitive,
64 FilterPrimitiveType type);
66 /**
67 * Sets the slot number 'slot' to be used as result from this filter.
68 * If output is not set, the output from last filter primitive is used as
69 * output from the filter.
70 * It is an error to specify a pre-defined slot as 'slot'. Such call does
71 * not have any effect to the state of filter or its primitives.
72 */
73 void set_output(int slot);
75 void set_x(SVGLength &lenght);
76 void set_y(SVGLength &length);
77 void set_width(SVGLength &length);
78 void set_height(SVGLength &length);
80 /**
81 * Sets the filter effects region.
82 * Passing an unset length (length._set == false) as any of the parameters
83 * results in that parameter not being changed.
84 * Filter will not hold any references to the passed SVGLength object after
85 * function returns.
86 * If any of these parameters does not get set, the default value, as
87 * defined in SVG standard, for that parameter is used instead.
88 */
89 void set_region(SVGLength &x, SVGLength &y,
90 SVGLength &width, SVGLength &height);
92 /**
93 * Resets the filter effects region to its default value as defined
94 * in SVG standard.
95 */
96 void reset_region();
98 /**
99 * Sets the width of intermediate images in pixels. If not set, suitable
100 * resolution is determined automatically. If x_pixels is less than zero,
101 * calling this function results in no changes to filter state.
102 */
103 void set_resolution(double x_pixels);
105 /**
106 * Sets the width and height of intermediate images in pixels. If not set,
107 * suitable resolution is determined automatically. If either parameter is
108 * less than zero, calling this function results in no changes to filter
109 * state.
110 */
111 void set_resolution(double x_pixels, double y_pixels);
113 /**
114 * Resets the filter resolution to its default value, i.e. automatically
115 * determined.
116 */
117 void reset_resolution();
119 /**
120 * Set the filterUnits-property. If not set, the default value of
121 * objectBoundingBox is used. If the parameter value is not a
122 * valid enumeration value from SPFilterUnits, no changes to filter state
123 * are made.
124 */
125 void set_filter_units(SPFilterUnits unit);
127 /**
128 * Set the primitiveUnits-properterty. If not set, the default value of
129 * userSpaceOnUseis used. If the parameter value is not a valid
130 * enumeration value from SPFilterUnits, no changes to filter state
131 * are made.
132 */
133 void set_primitive_units(SPFilterUnits unit);
135 /**
136 * Returns the amount of pixels the rendering area should be enlarged
137 * to prevent visual artefacts when filter needs to read pixels that
138 * are outside its output area (e.g. gaussian blur)
139 */
140 int get_enlarge(Matrix const &m);
141 /**
142 * Given an object bounding box, this function enlarges it so that
143 * it contains the filter effect area.
144 */
145 void bbox_enlarge(NRRectL &bbox);
147 /** Creates a new filter with space for one filter element */
148 Filter();
149 /**
150 * Creates a new filter with space for n filter elements. If number of
151 * filter elements is known beforehand, it's better to use this
152 * constructor.
153 */
154 Filter(int n);
155 /** Destroys the filter and all its primitives */
156 ~Filter();
158 private:
159 int _primitive_count;
160 int _primitive_table_size;
162 /** Amount of image slots used, when this filter was rendered last time */
163 int _slot_count;
165 /** Image slot, from which filter output should be read.
166 * Negative values mean 'not set' */
167 int _output_slot;
169 SVGLength _region_x;
170 SVGLength _region_y;
171 SVGLength _region_width;
172 SVGLength _region_height;
174 /* x- and y-resolutions for filter rendering.
175 * Negative values mean 'not set'.
176 * If _y_pixels is set, _x_pixels should be set, too. */
177 double _x_pixels;
178 double _y_pixels;
180 SPFilterUnits _filter_units;
181 SPFilterUnits _primitive_units;
183 FilterPrimitive ** _primitive;
185 void _create_constructor_table();
186 void _enlarge_primitive_table();
187 void _common_init();
188 };
191 } /* namespace NR */
196 #endif /* __NR_FILTER_H__ */
197 /*
198 Local Variables:
199 mode:c++
200 c-file-style:"stroustrup"
201 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
202 indent-tabs-mode:nil
203 fill-column:99
204 End:
205 */
206 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :