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Diffstat (limited to 'src/2geom/viewbox.cpp')
| -rw-r--r-- | src/2geom/viewbox.cpp | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/src/2geom/viewbox.cpp b/src/2geom/viewbox.cpp new file mode 100644 index 000000000..69bd0c487 --- /dev/null +++ b/src/2geom/viewbox.cpp @@ -0,0 +1,133 @@ +/** + * \file + * \brief Convenience class for SVG viewBox handling + *//* + * Authors: + * Krzysztof Kosiński <tweenk.pl@gmail.com> + * + * Copyright (C) 2013 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/transforms.h> +#include <2geom/viewbox.h> + +namespace Geom { + +/** Convert an align specification to coordinate fractions. */ +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; +} + +/** Obtain transformation from the viewbox to the specified viewport. */ +Affine ViewBox::transformTo(Geom::Rect const &viewport) const +{ + if (!_box) { + return Geom::Affine::identity(); + } + + // 1. translate viewbox to origin + Geom::Affine total = Translate(-_box->min()); + + // 2. compute scale + Geom::Point vdims = viewport.dimensions(); + Geom::Point bdims = _box->dimensions(); + Geom::Scale scale(vdims[X] / bdims[X], vdims[Y] / bdims[Y]); + + if (_align == ALIGN_NONE) { + // apply non-uniform scale + // = Scale(_box->dimensions()).inverse() * Scale(viewport.dimensions()) + total *= scale * Translate(viewport.min()); + } else { + double uscale = 0; + if (_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 = bdims * scale - vdims; + offset *= Scale(align_factors(_align)); + total *= Translate(-offset); + } + + return total; +} + +} // 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 : |