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Diffstat (limited to 'src/toys/lpe-framework.cpp')
| -rw-r--r-- | src/toys/lpe-framework.cpp | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/src/toys/lpe-framework.cpp b/src/toys/lpe-framework.cpp new file mode 100644 index 0000000..19f7267 --- /dev/null +++ b/src/toys/lpe-framework.cpp @@ -0,0 +1,128 @@ +/* + * A framework for writing an Inkscape Live Path Effect (LPE) toy. + * + * Copyright 2009 Johan Engelen <goejendaagh@zonnet.nl> + * + * This library is free software; you can redistribute it and/or + * modify it either under the terms of the GNU Lesser General Public + * License version 2.1 as published by the Free Software Foundation + * (the "LGPL") or, at your option, under the terms of the Mozilla + * Public License Version 1.1 (the "MPL"). If you do not alter this + * notice, a recipient may use your version of this file under either + * the MPL or the LGPL. + * + * You should have received a copy of the LGPL along with this library + * in the file COPYING-LGPL-2.1; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * You should have received a copy of the MPL along with this library + * in the file COPYING-MPL-1.1 + * + * The contents of this file are subject to the Mozilla Public License + * Version 1.1 (the "License"); you may not use this file except in + * compliance with the License. You may obtain a copy of the License at + * http://www.mozilla.org/MPL/ + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY + * OF ANY KIND, either express or implied. See the LGPL or the MPL for + * the specific language governing rights and limitations. + * + */ + +#include <string.h> +#include <stdint.h> +#include <toys/lpe-framework.h> + +#include <2geom/sbasis-to-bezier.h> +#include <2geom/affine.h> +#include <2geom/pathvector.h> + +#define LPE_CONVERSION_TOLERANCE 0.01 + +/** + * When the input path handles are moved, this method is called to re-execute the LPE and draw the result. + */ +void LPEToy::draw(cairo_t *cr, std::ostringstream *notify, int width, int height, bool save, std::ostringstream *timer_stream) +{ + using namespace Geom; + + Piecewise<D2<SBasis> > pwd2(curve_handle.asBezier()); + PathVector A = Geom::path_from_piecewise( pwd2, LPE_CONVERSION_TOLERANCE); + cairo_set_line_width (cr, 2); + cairo_set_source_rgba (cr, 1., 0.0, 0., 1); + cairo_path(cr, A); + cairo_stroke(cr); + + // perform the effect: + PathVector B = doEffect_path(A); + + cairo_set_line_width (cr, 1); + cairo_set_source_rgba (cr, 0., 0.0, 0., 1); + cairo_path(cr, B); + cairo_stroke(cr); + + Toy::draw(cr, notify, width, height, save,timer_stream); +} + +/** + * Initializes the LPE toy, and sets a simple default input path. + */ +LPEToy::LPEToy(){ + if(handles.empty()) { + handles.push_back(&curve_handle); + for(unsigned i = 0; i < 4; i++) { + curve_handle.push_back(150+uniform()*300,150+uniform()*300); + } + } +} + +/* + * Here be the doEffect function chain: (this is copied code from Inkscape) + */ +Geom::PathVector +LPEToy::doEffect_path (Geom::PathVector const &path_in) +{ + Geom::PathVector path_out; + + if ( !concatenate_before_pwd2 ) { + // default behavior + for (const auto & i : path_in) { + Geom::Piecewise<Geom::D2<Geom::SBasis> > pwd2_in = i.toPwSb(); + Geom::Piecewise<Geom::D2<Geom::SBasis> > pwd2_out = doEffect_pwd2(pwd2_in); + Geom::PathVector path = Geom::path_from_piecewise( pwd2_out, LPE_CONVERSION_TOLERANCE); + // add the output path vector to the already accumulated vector: + for (const auto & j : path) { + path_out.push_back(j); + } + } + } else { + // concatenate the path into possibly discontinuous pwd2 + Geom::Piecewise<Geom::D2<Geom::SBasis> > pwd2_in; + for (const auto & i : path_in) { + pwd2_in.concat( i.toPwSb() ); + } + Geom::Piecewise<Geom::D2<Geom::SBasis> > pwd2_out = doEffect_pwd2(pwd2_in); + path_out = Geom::path_from_piecewise( pwd2_out, LPE_CONVERSION_TOLERANCE); + } + + return path_out; +} + +Geom::Piecewise<Geom::D2<Geom::SBasis> > +LPEToy::doEffect_pwd2 (Geom::Piecewise<Geom::D2<Geom::SBasis> > const & pwd2_in) +{ + // default effect does nothing + return pwd2_in; +} + + + +/* + 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=4:softtabstop=4:fileencoding=utf-8:textwidth=99 : |