/** * @file * @brief Affine transformation classes *//* * Authors: * ? * Krzysztof Kosiński * Johan Engelen * * Copyright ?-2012 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 #include <2geom/point.h> #include <2geom/transforms.h> #include <2geom/rect.h> namespace Geom { /** @brief Zoom between rectangles. * Given two rectangles, compute a zoom that maps one to the other. * Rectangles are assumed to have the same aspect ratio. */ Zoom Zoom::map_rect(Rect const &old_r, Rect const &new_r) { Zoom ret; ret._scale = new_r.width() / old_r.width(); ret._trans = new_r.min() - old_r.min(); return ret; } // Point transformation methods. Point &Point::operator*=(Translate const &t) { _pt[X] += t.vec[X]; _pt[Y] += t.vec[Y]; return *this; } Point &Point::operator*=(Scale const &s) { _pt[X] *= s.vec[X]; _pt[Y] *= s.vec[Y]; return *this; } Point &Point::operator*=(Rotate const &r) { double x = _pt[X], y = _pt[Y]; _pt[X] = x * r.vec[X] - y * r.vec[Y]; _pt[Y] = y * r.vec[X] + x * r.vec[Y]; return *this; } Point &Point::operator*=(HShear const &h) { _pt[X] += h.f * _pt[X]; return *this; } Point &Point::operator*=(VShear const &v) { _pt[Y] += v.f * _pt[Y]; return *this; } Point &Point::operator*=(Zoom const &z) { _pt[X] += z._trans[X]; _pt[Y] += z._trans[Y]; _pt[X] *= z._scale; _pt[Y] *= z._scale; return *this; } // Affine multiplication methods. /** @brief Combine this transformation with a translation. */ Affine &Affine::operator*=(Translate const &t) { _c[4] += t[X]; _c[5] += t[Y]; return *this; } /** @brief Combine this transformation with scaling. */ Affine &Affine::operator*=(Scale const &s) { _c[0] *= s[X]; _c[1] *= s[Y]; _c[2] *= s[X]; _c[3] *= s[Y]; _c[4] *= s[X]; _c[5] *= s[Y]; return *this; } /** @brief Combine this transformation a rotation. */ Affine &Affine::operator*=(Rotate const &r) { // TODO: we just convert the Rotate to an Affine and use the existing operator*=() // is there a better way? *this *= (Affine) r; return *this; } /** @brief Combine this transformation with horizontal shearing (skew). */ Affine &Affine::operator*=(HShear const &h) { _c[0] += h.f * _c[1]; _c[2] += h.f * _c[3]; _c[4] += h.f * _c[5]; return *this; } /** @brief Combine this transformation with vertical shearing (skew). */ Affine &Affine::operator*=(VShear const &v) { _c[1] += v.f * _c[0]; _c[3] += v.f * _c[2]; _c[5] += v.f * _c[4]; return *this; } Affine &Affine::operator*=(Zoom const &z) { _c[0] *= z._scale; _c[1] *= z._scale; _c[2] *= z._scale; _c[3] *= z._scale; _c[4] += z._trans[X]; _c[5] += z._trans[Y]; _c[4] *= z._scale; _c[5] *= z._scale; return *this; } Affine Rotate::around(Point const &p, Coord angle) { Affine result = Translate(-p) * Rotate(angle) * Translate(p); return result; } Affine reflection(Point const & vector, Point const & origin) { Geom::Point vn = unit_vector(vector); Coord cx2 = vn[X] * vn[X]; Coord cy2 = vn[Y] * vn[Y]; Coord c2xy = 2 * vn[X] * vn[Y]; Affine mirror ( cx2 - cy2, c2xy, c2xy, cy2 - cx2, 0, 0 ); return Translate(-origin) * mirror * Translate(origin); } // this checks whether the requirements of TransformConcept are satisfied for all transforms. // if you add a new transform type, include it here! void check_transforms() { #ifdef BOOST_CONCEPT_ASSERT BOOST_CONCEPT_ASSERT((TransformConcept)); BOOST_CONCEPT_ASSERT((TransformConcept)); BOOST_CONCEPT_ASSERT((TransformConcept)); BOOST_CONCEPT_ASSERT((TransformConcept)); BOOST_CONCEPT_ASSERT((TransformConcept)); BOOST_CONCEPT_ASSERT((TransformConcept)); BOOST_CONCEPT_ASSERT((TransformConcept)); // Affine is also a transform #endif // check inter-transform multiplication Affine m; Translate t(Translate::identity()); Scale s(Scale::identity()); Rotate r(Rotate::identity()); HShear h(HShear::identity()); VShear v(VShear::identity()); Zoom z(Zoom::identity()); // notice that the first column is always the same and enumerates all transform types, // while the second one changes to each transform type in turn. // cppcheck-suppress redundantAssignment m = t * t; m = t * s; m = t * r; m = t * h; m = t * v; m = t * z; m = s * t; m = s * s; m = s * r; m = s * h; m = s * v; m = s * z; m = r * t; m = r * s; m = r * r; m = r * h; m = r * v; m = r * z; m = h * t; m = h * s; m = h * r; m = h * h; m = h * v; m = h * z; m = v * t; m = v * s; m = v * r; m = v * h; m = v * v; m = v * z; m = z * t; m = z * s; m = z * r; m = z * h; m = z * v; m = z * z; } } // 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 :