diff options
Diffstat (limited to 'src/display/control/canvas-item-bpath.cpp')
| -rw-r--r-- | src/display/control/canvas-item-bpath.cpp | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/src/display/control/canvas-item-bpath.cpp b/src/display/control/canvas-item-bpath.cpp new file mode 100644 index 0000000..d99588e --- /dev/null +++ b/src/display/control/canvas-item-bpath.cpp @@ -0,0 +1,223 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/** + * A class to represent a Bezier path. + */ + +/* + * Author: + * Tavmjong Bah + * + * Copyright (C) 2020 Tavmjong Bah + * + * Rewrite of SPCanvasBPath + * + * Released under GNU GPL v2+, read the file 'COPYING' for more information. + */ + +#include "canvas-item-bpath.h" + +#include "color.h" // SP_RGBA_x_F +#include "display/curve.h" +#include "display/cairo-utils.h" +#include "helper/geom.h" // bounds_exact_transformed() + +namespace Inkscape { + +/** + * Create a null control bpath. + */ +CanvasItemBpath::CanvasItemBpath(CanvasItemGroup *group) + : CanvasItem(group) +{ + _name = "CanvasItemBpath:Null"; + _pickable = true; // For now, everyone gets events from this class! +} + +/** + * Create a control bpath. Path is in document coordinates. + */ +CanvasItemBpath::CanvasItemBpath(CanvasItemGroup *group, Geom::PathVector path, bool phantom_line) + : CanvasItem(group) + , _path(std::move(path)) + , _phantom_line(phantom_line) +{ + _name = "CanvasItemBpath"; + _pickable = true; // For now, everyone gets events from this class! + request_update(); // Render immediately or temporary bpaths won't show. +} + +/** + * Set a control bpath. Curve is in document coordinates. + */ +void CanvasItemBpath::set_bpath(SPCurve const *curve, bool phantom_line) +{ + set_bpath(curve ? curve->get_pathvector() : Geom::PathVector(), phantom_line); +} + +/** + * Set a control bpath. Path is in document coordinates. + */ +void CanvasItemBpath::set_bpath(Geom::PathVector path, bool phantom_line) +{ + defer([=, path = std::move(path)] () mutable { + _path = std::move(path); + _phantom_line = phantom_line; + request_update(); + }); +} + +/** + * Set the fill color and fill rule. + */ +void CanvasItemBpath::set_fill(uint32_t fill, SPWindRule fill_rule) +{ + defer([=] { + if (_fill == fill && _fill_rule == fill_rule) return; + _fill = fill; + _fill_rule = fill_rule; + request_redraw(); + }); +} + +void CanvasItemBpath::set_dashes(std::vector<double> &&dashes) +{ + defer([=, dashes = std::move(dashes)] () mutable { + _dashes = std::move(dashes); + }); +} + +/** + * Set the stroke width + */ +void CanvasItemBpath::set_stroke_width(double width) +{ + defer([=] { + if (_stroke_width == width) return; + _stroke_width = width; + request_redraw(); + }); +} + +/** + * Returns distance between point in canvas units and nearest point on bpath. + */ +double CanvasItemBpath::closest_distance_to(Geom::Point const &p) const +{ + double d = Geom::infinity(); + + // Convert p to document coordinates (quicker than converting path to canvas units). + Geom::Point p_doc = p * affine().inverse(); + _path.nearestTime(p_doc, &d); + d *= affine().descrim(); // Uniform scaling and rotation only. + + return d; +} + +/** + * Returns true if point p (in canvas units) is within tolerance (canvas units) distance of bpath. + */ +bool CanvasItemBpath::contains(Geom::Point const &p, double tolerance) +{ + if (tolerance == 0) { + tolerance = 1; // Need a minimum tolerance value or always returns false. + } + + // Check for 'inside' a filled bpath if a fill is being used. + if ((_fill & 0xff) != 0) { + Geom::Point p_doc = p * affine().inverse(); + if (_path.winding(p_doc) % 2 != 0) { + return true; + } + } + + // Otherwise see how close we are to the outside line. + return closest_distance_to(p) < tolerance; +} + +/** + * Update and redraw control bpath. + */ +void CanvasItemBpath::_update(bool) +{ + // Queue redraw of old area (erase previous content). + request_redraw(); + + if (_path.empty()) { + _bounds = {}; + return; + } + + _bounds = expandedBy(bounds_exact_transformed(_path, affine()), 2); + + // Queue redraw of new area + request_redraw(); +} + +/** + * Render bpath to screen via Cairo. + */ +void CanvasItemBpath::_render(Inkscape::CanvasItemBuffer &buf) const +{ + bool do_fill = (_fill & 0xff) != 0; // Not invisible. + bool do_stroke = (_stroke & 0xff) != 0; // Not invisible. + + if (!do_fill && !do_stroke) { + // Both fill and stroke invisible. + return; + } + + buf.cr->save(); + + // Setup path + buf.cr->set_tolerance(0.5); + buf.cr->begin_new_path(); + + feed_pathvector_to_cairo(buf.cr->cobj(), _path, affine(), buf.rect, + /* optimize_stroke */ !do_fill, 1); + + // Do fill + if (do_fill) { + buf.cr->set_source_rgba(SP_RGBA32_R_F(_fill), SP_RGBA32_G_F(_fill), + SP_RGBA32_B_F(_fill), SP_RGBA32_A_F(_fill)); + buf.cr->set_fill_rule(_fill_rule == SP_WIND_RULE_EVENODD ? + Cairo::FILL_RULE_EVEN_ODD : Cairo::FILL_RULE_WINDING); + buf.cr->fill_preserve(); + } + + // Do stroke + if (do_stroke) { + + if (!_dashes.empty()) { + buf.cr->set_dash(_dashes, 0.0); // 0.0 is offset + } + + if (_phantom_line) { + buf.cr->set_source_rgba(1.0, 1.0, 1.0, 0.25); + buf.cr->set_line_width(2.0); + buf.cr->stroke_preserve(); + } + + buf.cr->set_source_rgba(SP_RGBA32_R_F(_stroke), SP_RGBA32_G_F(_stroke), + SP_RGBA32_B_F(_stroke), SP_RGBA32_A_F(_stroke)); + buf.cr->set_line_width(_stroke_width); + buf.cr->stroke(); + + } else { + buf.cr->begin_new_path(); // Clears path + } + + buf.cr->restore(); +} + +} // namespace Inkscape + +/* + 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 : |