nr-filter.h revision aca3b339a427a3f0a8a6eec08e797e3dc458815f
#ifndef __NR_FILTER_H__
#define __NR_FILTER_H__
/*
* SVG filters rendering
*
* Author:
* Niko Kiirala <niko@kiirala.com>
*
* Copyright (C) 2006 Niko Kiirala
*
* Released under GNU GPL, read the file 'COPYING' for more information
*/
//#include "display/nr-arena-item.h"
#include "display/nr-filter-primitive.h"
#include "display/nr-filter-types.h"
#include "libnr/nr-pixblock.h"
#include "libnr/nr-matrix.h"
#include "libnr/nr-rect.h"
#include "svg/svg-length.h"
#include "sp-filter-units.h"
#include "gc-managed.h"
struct NRArenaItem;
namespace NR {
class Filter : public Inkscape::GC::Managed<> {
public:
int render(NRArenaItem const *item, NRPixBlock *pb);
/**
* 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 accomodate 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 corrensponds 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 &x, SVGLength &y,
SVGLength &width, SVGLength &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-properterty. If not set, the default value of
* userSpaceOnUseis 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(NRRectL &area, Matrix const &m);
/**
* Given an object bounding box, this function enlarges it so that
* it contains the filter effect area.
*/
void bbox_enlarge(NRRectL &bbox);
/** 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 */
~Filter();
private:
int _primitive_count;
int _primitive_table_size;
/** 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;
FilterPrimitive ** _primitive;
void _create_constructor_table();
void _enlarge_primitive_table();
void _common_init();
};
} /* namespace NR */
#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:
*/
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