// SPDX-License-Identifier: GPL-2.0-or-later #ifndef INKSCAPE_DISPLAY_NR_FILTER_H #define INKSCAPE_DISPLAY_NR_FILTER_H /* * SVG filters rendering * * Author: * Niko Kiirala * * Copyright (C) 2006 Niko Kiirala * * Released under GNU GPL v2+, read the file 'COPYING' for more information. */ #include #include #include "display/nr-filter-primitive.h" #include "display/nr-filter-types.h" #include "svg/svg-length.h" #include "object/sp-filter-units.h" namespace Inkscape { class DrawingContext; class DrawingItem; class RenderContext; namespace Filters { class Filter final { public: /// Update any embedded DrawingItems prior to rendering. void update(); /** 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, RenderContext &rc) const; /** * 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 a valid filter primitive type or a filter * primitive of such type cannot be created. */ void add_primitive(std::unique_ptr primitive); /** * 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(); /** * 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 for that * parameter as defined in the SVG standard 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 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 x_pixels, double 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) const; // returns cache score factor double complexity(Geom::Affine const &ctm) const; // says whether the filter accesses any of the background images bool uses_background() const; /** 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); private: std::vector> primitives; /** 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 _common_init(); static int _resolution_limit(FilterQuality quality); std::pair _filter_resolution(Geom::Rect const &area, Geom::Affine const &trans, FilterQuality q) const; }; } // namespace Filters } // namespace Inkscape #endif // INKSCAPE_DISPLAY_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 :