nr-filter-units.h

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// SPDX-License-Identifier: GPL-2.0-or-later
#ifndef SEEN_NR_FILTER_UNITS_H
#define SEEN_NR_FILTER_UNITS_H
 
/*
 * Utilities for handling coordinate system transformations in filters
 *
 * Author:
 *   Niko Kiirala <niko@kiirala.com>
 *
 * Copyright (C) 2007 Niko Kiirala
 *
 * Released under GNU GPL v2+, read the file 'COPYING' for more information.
 */
 
#include "object/sp-filter-units.h"
#include <2geom/affine.h>
#include <2geom/rect.h>
 
namespace Inkscape {
namespace Filters {
 
/* Notes:
 * - "filter units" is a coordinate system where the filter region is contained
 *   between (0,0) and (1,1). Do not confuse this with the filterUnits property
 * - "primitive units" is the coordinate system in which all lengths and distances
 *   in the filter definition should be interpreted. They are affected by the value
 *   of the primitiveUnits attribute
 * - "pb" is the coordinate system in which filter rendering happens.
 *   It might be aligned with user or screen coordinates depending on
 *   the filter primitives used in the filter.
 * - "display" are world coordinates of the canvas - pixel grid coordinates
 *   of the drawing area translated so that (0,0) corresponds to the document origin
 */
class FilterUnits {
public:
    FilterUnits();
    FilterUnits(SPFilterUnits const filterUnits, SPFilterUnits const primitiveUnits);
 
    void set_ctm(Geom::Affine const &ctm);
 
    void set_resolution(double const x_res, double const y_res);
 
    void set_item_bbox(Geom::OptRect const &bbox);
 
    void set_filter_area(Geom::OptRect const &area);
 
    void set_paraller(bool const paraller);
 
    void set_automatic_resolution(bool const automatic);
 
    Geom::OptRect get_item_bbox() const { return item_bbox; };
 
    Geom::OptRect get_filter_area() const { return filter_area; };
 
    SPFilterUnits get_filter_units() const { return filterUnits; };
 
    SPFilterUnits get_primitive_units() const { return primitiveUnits; };
 
    Geom::Affine get_matrix_user2pb() const;
 
    Geom::Affine get_matrix_filterunits2pb() const;
 
    Geom::Affine get_matrix_primitiveunits2pb() const;
 
    Geom::Affine get_matrix_display2pb() const;
 
    Geom::Affine get_matrix_pb2display() const;
 
    Geom::Affine get_matrix_user2filterunits() const;
 
    Geom::Affine get_matrix_user2primitiveunits() const;
 
    Geom::IntRect get_pixblock_filterarea_paraller() const;
 
    FilterUnits& operator=(FilterUnits const &other);
 
private:
    Geom::Affine get_matrix_units2pb(SPFilterUnits units) const;
    Geom::Affine get_matrix_user2units(SPFilterUnits units) const;
 
    SPFilterUnits filterUnits, primitiveUnits;
    double resolution_x, resolution_y;
    bool paraller_axis;
    bool automatic_resolution;
    Geom::Affine ctm;
    Geom::OptRect item_bbox;
    Geom::OptRect filter_area;
};
 
} // namespace Filters
} // namespace Inkscape
 
#endif /* SEEN_INKSCAPE_NR_FILTER_UNITS_H */
/*
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  End:
*/
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