144 lines
3.0 KiB
C++
144 lines
3.0 KiB
C++
/*
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Copyright (C) 2011-2013 Paul Davis
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Author: Carl Hetherington <cth@carlh.net>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include "canvas/polygon.h"
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using namespace ArdourCanvas;
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Polygon::Polygon (Canvas* c)
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: PolyItem (c)
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, multiple (0)
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, constant (0)
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, cached_size (0)
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{
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}
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Polygon::Polygon (Item* parent)
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: PolyItem (parent)
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, multiple (0)
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, constant (0)
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, cached_size (0)
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{
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}
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Polygon::~Polygon ()
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{
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delete [] multiple;
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delete [] constant;
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}
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void
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Polygon::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) const
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{
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if (_outline || _fill) {
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render_path (area, context);
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if (!_points.empty ()) {
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/* close path */
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Duple p = item_to_window (Duple (_points.front().x, _points.front().y));
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context->line_to (p.x, p.y);
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}
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}
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if (_outline) {
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setup_outline_context (context);
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if (_fill) {
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context->stroke_preserve ();
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} else {
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context->stroke ();
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}
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}
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if (_fill) {
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setup_fill_context (context);
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context->fill ();
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}
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}
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void
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Polygon::cache_shape_computation () const
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{
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Points::size_type npoints = _points.size();
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if (npoints == 0) {
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return;
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}
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Points::size_type i;
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Points::size_type j = npoints -1;
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if (cached_size < npoints) {
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cached_size = npoints;
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delete [] multiple;
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multiple = new float[cached_size];
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delete [] constant;
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constant = new float[cached_size];
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}
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for (i = 0; i < npoints; i++) {
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if (_points[j].y == _points[i].y) {
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constant[i] = _points[i].x;
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multiple[i] = 0;
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} else {
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constant[i] = _points[i].x-(_points[i].y*_points[j].x)/(_points[j].y-_points[i].y)+(_points[i].y*_points[i].x)/(_points[j].y-_points[i].y);
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multiple[i] = (_points[j].x-_points[i].x)/(_points[j].y-_points[i].y);
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}
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j = i;
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}
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}
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bool
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Polygon::covers (Duple const & point) const
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{
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Duple p = window_to_item (point);
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Points::size_type npoints = _points.size();
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if (npoints == 0) {
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return false;
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}
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Points::size_type i;
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Points::size_type j = npoints -1;
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bool oddNodes = false;
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if (_bounding_box_dirty) {
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compute_bounding_box ();
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}
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for (i = 0; i < npoints; i++) {
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if (((_points[i].y < p.y && _points[j].y >= p.y) || (_points[j].y < p.y && _points[i].y >= p.y))) {
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oddNodes ^= (p.y * multiple[i] + constant[i] < p.x);
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}
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j = i;
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}
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return oddNodes;
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}
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void
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Polygon::compute_bounding_box () const
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{
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PolyItem::compute_bounding_box ();
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cache_shape_computation ();
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}
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