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Diffstat (limited to 'src/display/nr-filter.h')
| -rw-r--r-- | src/display/nr-filter.h | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/src/display/nr-filter.h b/src/display/nr-filter.h new file mode 100644 index 0000000..caa7188 --- /dev/null +++ b/src/display/nr-filter.h @@ -0,0 +1,224 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +#ifndef SEEN_NR_FILTER_H +#define SEEN_NR_FILTER_H + +/* + * SVG filters rendering + * + * Author: + * Niko Kiirala <niko@kiirala.com> + * + * Copyright (C) 2006 Niko Kiirala + * + * Released under GNU GPL v2+, read the file 'COPYING' for more information. + */ + +//#include "display/nr-arena-item.h" +#include <cairo.h> +#include "display/nr-filter-primitive.h" +#include "display/nr-filter-types.h" +#include "svg/svg-length.h" +#include "object/sp-filter-units.h" +#include "inkgc/gc-managed.h" + +namespace Inkscape { +class DrawingContext; +class DrawingItem; + +namespace Filters { + +class Filter { +public: + /** Given background state from @a bgdc and an intermediate rendering from the surface + * backing @a graphic, modify the contents of the surface backing @a graphic to represent + * the results of filter rendering. @a bgarea and @a area specify bounding boxes + * of both surfaces in world coordinates; Cairo contexts are assumed to be in default state + * (0,0 = surface origin, no path, OVER operator) */ + int render(Inkscape::DrawingItem const *item, DrawingContext &graphic, DrawingContext *bgdc); + + /** + * Creates a new filter primitive under this filter object. + * New primitive is placed so that it will be executed after all filter + * primitives defined beforehand for this filter object. + * Should this filter not have enough space for a new primitive, the filter + * is enlarged to accommodate the new filter element. It may be enlarged by + * more that one element. + * Returns a handle (non-negative integer) to the filter primitive created. + * Returns -1, if type is not valid filter primitive type or filter + * primitive of such type cannot be created. + */ + int add_primitive(FilterPrimitiveType type); + /** + * Removes all filter primitives from this filter. + * All pointers to filter primitives inside this filter should be + * considered invalid after calling this function. + */ + void clear_primitives(); + /** + * Replaces filter primitive pointed by 'target' with a new filter + * primitive of type 'type' + * If 'target' does not correspond to any primitive inside this filter OR + * 'type' is not a valid filter primitive type OR + * filter primitive of such type cannot be created, + * this function returns -1 and doesn't change the internal state of this + * filter. + * Otherwise, a new filter primitive is created. Any pointers to filter + * primitive 'target' should be considered invalid. A handle to the + * newly created primitive is returned. + */ + int replace_primitive(int primitive, FilterPrimitiveType type); + + /** + * Returns a pointer to the primitive, which the handle corresponds to. + * If the handle is not valid, returns NULL. + */ + FilterPrimitive *get_primitive(int handle); + + /** + * Sets the slot number 'slot' to be used as result from this filter. + * If output is not set, the output from last filter primitive is used as + * output from the filter. + * It is an error to specify a pre-defined slot as 'slot'. Such call does + * not have any effect to the state of filter or its primitives. + */ + void set_output(int slot); + + void set_x(SVGLength const &length); + void set_y(SVGLength const &length); + void set_width(SVGLength const &length); + void set_height(SVGLength const &length); + + /** + * Sets the filter effects region. + * Passing an unset length (length._set == false) as any of the parameters + * results in that parameter not being changed. + * Filter will not hold any references to the passed SVGLength object after + * function returns. + * If any of these parameters does not get set, the default value, as + * defined in SVG standard, for that parameter is used instead. + */ + void set_region(SVGLength const &x, SVGLength const &y, + SVGLength const &width, SVGLength const &height); + + /** + * Resets the filter effects region to its default value as defined + * in SVG standard. + */ + void reset_region(); + + /** + * Sets the width of intermediate images in pixels. If not set, suitable + * resolution is determined automatically. If x_pixels is less than zero, + * calling this function results in no changes to filter state. + */ + void set_resolution(double const x_pixels); + + /** + * Sets the width and height of intermediate images in pixels. If not set, + * suitable resolution is determined automatically. If either parameter is + * less than zero, calling this function results in no changes to filter + * state. + */ + void set_resolution(double const x_pixels, double const y_pixels); + + /** + * Resets the filter resolution to its default value, i.e. automatically + * determined. + */ + void reset_resolution(); + + /** + * Set the filterUnits-property. If not set, the default value of + * objectBoundingBox is used. If the parameter value is not a + * valid enumeration value from SPFilterUnits, no changes to filter state + * are made. + */ + void set_filter_units(SPFilterUnits unit); + + /** + * Set the primitiveUnits-property. If not set, the default value of + * userSpaceOnUse is used. If the parameter value is not a valid + * enumeration value from SPFilterUnits, no changes to filter state + * are made. + */ + void set_primitive_units(SPFilterUnits unit); + + /** + * Modifies the given area to accommodate for filters needing pixels + * outside the rendered area. + * When this function returns, area contains the area that needs + * to be rendered so that after filtering, the original area is + * drawn correctly. + */ + void area_enlarge(Geom::IntRect &area, Inkscape::DrawingItem const *item) const; + /** + * Returns the filter effects area in user coordinate system. + * The given bounding box should be a bounding box as specified in + * SVG standard and in user coordinate system. + */ + Geom::OptRect filter_effect_area(Geom::OptRect const &bbox); + + // returns cache score factor + double complexity(Geom::Affine const &ctm); + + // says whether the filter accesses any of the background images + bool uses_background(); + + /** Creates a new filter with space for one filter element */ + Filter(); + /** + * Creates a new filter with space for n filter elements. If number of + * filter elements is known beforehand, it's better to use this + * constructor. + */ + Filter(int n); + /** Destroys the filter and all its primitives */ + virtual ~Filter(); + +private: + std::vector<FilterPrimitive*> _primitive; + /** Amount of image slots used, when this filter was rendered last time */ + int _slot_count; + + /** Image slot, from which filter output should be read. + * Negative values mean 'not set' */ + int _output_slot; + + SVGLength _region_x; + SVGLength _region_y; + SVGLength _region_width; + SVGLength _region_height; + + /* x- and y-resolutions for filter rendering. + * Negative values mean 'not set'. + * If _y_pixels is set, _x_pixels should be set, too. */ + double _x_pixels; + double _y_pixels; + + SPFilterUnits _filter_units; + SPFilterUnits _primitive_units; + + void _create_constructor_table(); + void _common_init(); + int _resolution_limit(FilterQuality const quality) const; + std::pair<double,double> _filter_resolution(Geom::Rect const &area, + Geom::Affine const &trans, + FilterQuality const q) const; +}; + + +} /* namespace Filters */ +} /* namespace Inkscape */ + + +#endif /* __NR_FILTER_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:fileencoding=utf-8:textwidth=99 : |