rect.cpp

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/* Axis-aligned rectangle
 *
 * Authors:
 *   Michael Sloan <mgsloan@gmail.com>
 *   Krzysztof Kosiński <tweenk.pl@gmail.com>
 * Copyright 2007-2011 Authors
 *
 * 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 <2geom/rect.h>
#include <2geom/transforms.h>
 
namespace Geom {
 
Point align_factors(Align g) {
    Point p;
    switch (g) {
    case ALIGN_XMIN_YMIN:
        p[X] = 0.0;
        p[Y] = 0.0;
        break;
    case ALIGN_XMID_YMIN:
        p[X] = 0.5;
        p[Y] = 0.0;
        break;
    case ALIGN_XMAX_YMIN:
        p[X] = 1.0;
        p[Y] = 0.0;
        break;
    case ALIGN_XMIN_YMID:
        p[X] = 0.0;
        p[Y] = 0.5;
        break;
    case ALIGN_XMID_YMID:
        p[X] = 0.5;
        p[Y] = 0.5;
        break;
    case ALIGN_XMAX_YMID:
        p[X] = 1.0;
        p[Y] = 0.5;
        break;
    case ALIGN_XMIN_YMAX:
        p[X] = 0.0;
        p[Y] = 1.0;
        break;
    case ALIGN_XMID_YMAX:
        p[X] = 0.5;
        p[Y] = 1.0;
        break;
    case ALIGN_XMAX_YMAX:
        p[X] = 1.0;
        p[Y] = 1.0;
        break;
    default:
        break;
    }
    return p;
}
 
 
Rect &Rect::operator*=(Affine const &m) {
    Point pts[4];
    for (unsigned i=0; i<4; ++i) pts[i] = corner(i) * m;
    Coord minx = std::min(std::min(pts[0][X], pts[1][X]), std::min(pts[2][X], pts[3][X]));
    Coord miny = std::min(std::min(pts[0][Y], pts[1][Y]), std::min(pts[2][Y], pts[3][Y]));
    Coord maxx = std::max(std::max(pts[0][X], pts[1][X]), std::max(pts[2][X], pts[3][X]));
    Coord maxy = std::max(std::max(pts[0][Y], pts[1][Y]), std::max(pts[2][Y], pts[3][Y]));
    f[X].setMin(minx); f[X].setMax(maxx);
    f[Y].setMin(miny); f[Y].setMax(maxy);
    return *this;
}
 
Affine Rect::transformTo(Rect const &viewport, Aspect const &aspect) const
{
    // 1. translate viewbox to origin
    Geom::Affine total = Translate(-min());
 
    // 2. compute scale
    Geom::Point vdims = viewport.dimensions();
    Geom::Point dims = dimensions();
    Geom::Scale scale(vdims[X] / dims[X], vdims[Y] / dims[Y]);
 
    if (aspect.align == ALIGN_NONE) {
        // apply non-uniform scale
        total *= scale * Translate(viewport.min());
    } else {
        double uscale = 0;
        if (aspect.expansion == EXPANSION_MEET) {
            uscale = std::min(scale[X], scale[Y]);
        } else {
            uscale = std::max(scale[X], scale[Y]);
        }
        scale = Scale(uscale);
 
        // compute offset for align
        Geom::Point offset = vdims - dims * scale;
        offset *= Scale(align_factors(aspect.align));
        total *= scale * Translate(viewport.min() + offset);
    }
 
    return total;
}
 
Rect Rect::expandedBy(Coord amount) const
{
    auto copy{*this};
    copy.expandBy(amount);
    return copy;
}
 
Rect Rect::expandedBy(Coord x, Coord y) const
{
    auto copy{*this};
    copy.expandBy(x, y);
    return copy;
}
 
Rect Rect::shrunkBy(Coord amount) const
{
    auto copy{*this};
    copy.shrinkBy(amount);
    return copy;
}
 
Rect Rect::shrunkBy(Coord x, Coord y) const
{
    auto copy{*this};
    copy.shrinkBy(x, y);
    return copy;
}
 
Coord distanceSq(Point const &p, Rect const &rect)
{
    double dx = 0, dy = 0;
    if ( p[X] < rect.left() ) {
        dx = p[X] - rect.left();
    } else if ( p[X] > rect.right() ) {
        dx = rect.right() - p[X];
    }
    if (p[Y] < rect.top() ) {
        dy = rect.top() - p[Y];
    } else if (  p[Y] > rect.bottom() ) {
        dy = p[Y] - rect.bottom();
    }
    return dx*dx+dy*dy;
}
 
Coord distance(Point const &p, Rect const &rect)
{
    // copy of distanceSq, because we need to use hypot()
    double dx = 0, dy = 0;
    if ( p[X] < rect.left() ) {
        dx = p[X] - rect.left();
    } else if ( p[X] > rect.right() ) {
        dx = rect.right() - p[X];
    }
    if (p[Y] < rect.top() ) {
        dy = rect.top() - p[Y];
    } else if (  p[Y] > rect.bottom() ) {
        dy = p[Y] - rect.bottom();
    }
    return hypot(dx, dy);
}
 
Coord distanceSq(Point const &p, OptRect const &rect)
{
    if (!rect) return std::numeric_limits<Coord>::max();
    return distanceSq(p, *rect);
}
Coord distance(Point const &p, OptRect const &rect)
{
    if (!rect) return std::numeric_limits<Coord>::max();
    return distance(p, *rect);
}
 
} // namespace Geom
 
/*
  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:fileencoding=utf-8:textwidth=99 :