diff options
author | Norbert Preining <norbert@preining.info> | 2019-09-02 13:46:59 +0900 |
---|---|---|
committer | Norbert Preining <norbert@preining.info> | 2019-09-02 13:46:59 +0900 |
commit | e0c6872cf40896c7be36b11dcc744620f10adf1d (patch) | |
tree | 60335e10d2f4354b0674ec22d7b53f0f8abee672 /graphics/epix/circle.cc |
Initial commit
Diffstat (limited to 'graphics/epix/circle.cc')
-rw-r--r-- | graphics/epix/circle.cc | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/graphics/epix/circle.cc b/graphics/epix/circle.cc new file mode 100644 index 0000000000..b81150587a --- /dev/null +++ b/graphics/epix/circle.cc @@ -0,0 +1,197 @@ +/* + * circle.cc -- ePiX::Circle class + * + * This file is part of ePiX, a C++ library for creating high-quality + * figures in LaTeX + * + * Version 1.1.9 + * Last Change: July 30, 2007 + */ + +/* + * Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007 + * Andrew D. Hwang <rot 13 nujnat at zngupf dot ubylpebff dot rqh> + * Department of Mathematics and Computer Science + * College of the Holy Cross + * Worcester, MA, 01610-2395, USA + */ + +/* + * ePiX is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * ePiX is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public + * License for more details. + * + * You should have received a copy of the GNU General Public License + * along with ePiX; if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ +#include <cmath> + +#include "errors.h" + +#include "constants.h" + +#include "triples.h" +#include "state.h" + +#include "segment.h" +#include "frame.h" +#include "camera.h" + +#include "path.h" + +#include "paint_style.h" + +#include "intersections.h" + +#include "circle.h" + +namespace ePiX { + + static const double EPS(EPIX_EPSILON); + + Circle::Circle(const P& ctr, const double rad, const P& perp) + : m_center(ctr), m_radius(rad), m_perp(perp), m_malformed(false) + { + double temp(norm(perp)); + if (temp < EPS) + { + epix_warning("Degenerate circle normal, using (0,0,1)"); + m_perp=E_3; + } + + else + m_perp *= (1.0/temp); // normalize + } + + // point-and-center constructor -- parallel to (x1,x2,0)-plane + Circle::Circle(const P& ctr, const P& pt) + : m_center(ctr), m_radius(norm(pt - ctr)), m_perp(E_3), m_malformed(false) + { + if (fabs(E_3|(pt - ctr)) > EPS) + epix_warning("Circle requested with point not in (x,y) plane"); + } + + // three-point circle constructor + Circle::Circle(const P& pt1, const P& pt2, const P& pt3) + : m_malformed(false) + { + P D21(pt2-pt1), D31(pt3-pt1), D32(pt3-pt2), N(D21*D31); + + if (norm(D21) < EPS || + norm(D31) < EPS || + norm(D32) < EPS || + norm(N) < EPS) + { + epix_warning("Collinear points in Circle constructor"); + m_malformed = true; + } + + else + { + m_perp = (1.0/norm(N))*N; + + P q2(0.5*(pt1+pt2)); + P dir2(m_perp*(q2-pt1)); + + P q3(0.5*(pt1+pt3)); + P dir3(m_perp*(q3-pt1)); + + m_center = Segment(q2, q2+dir2)*Segment(q3, q3+dir3); + m_radius = norm(m_center - pt1); + } + } + + + Circle::Circle(bool tag) : m_malformed(true) { } + + + P Circle::center() const + { + return m_center; + } + + double Circle::radius() const + { + return m_radius; + } + + P Circle::perp() const + { + return m_perp; + } + + bool Circle::malformed() const + { + return m_malformed; + } + + // translation + Circle& Circle::shift(const P& arg) + { + if (!m_malformed) + m_center += arg; + return *this; + } + + Circle& Circle::move_to(const P& arg) + { + if (!m_malformed) + m_center = arg; + return *this; + } + + // scale radius + Circle& Circle::scale(const double c) + { + if (!m_malformed) + m_radius *= c; + return *this; + } + + + // project to screen by camera + void Circle::draw() const + { + if (m_malformed) + return; + + // else + double r(m_radius); + P N(m_perp); + frame axes; // standard basis + + if (EPS <= norm(N*E_3)) + axes = frame(E_3*N, E_3, N); + + path data(m_center, r*(axes.sea()), r*(axes.sky()), 0, full_turn()); + data.close().fill(the_paint_style().fill_flag()); + data.draw(); + } + + + //// global functions //// + void circle(const P& ctr, const double rad, const P& perp) + { + Circle C(ctr, rad, perp); + C.draw(); + } + + void circle(const P& ctr, const P& pt) + { + Circle C(ctr, pt); + C.draw(); + } + + void circle(const P& pt1, const P& pt2, const P& pt3) + { + Circle C(pt1, pt2, pt3); + C.draw(); + } +} // end of namespace |