basegfx/source/workbench/bezierclip.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #pragma once
  21
  22 #include <vector>
  23
  24 struct Point2D
  25 {
  26     typedef double value_type;
  27     Point2D( double _x, double _y ) : x(_x), y(_y) {}
  28     Point2D() : x(), y() {}
  29     double x;
  30     double y;
  31 };
  32
  33 struct Bezier
  34 {
  35     Point2D p0;
  36     Point2D p1;
  37     Point2D p2;
  38     Point2D p3;
  39
  40     Point2D&        operator[]( int i ) { return reinterpret_cast<Point2D*>(this)[i]; }
  41     const Point2D&  operator[]( int i ) const { return reinterpret_cast<const Point2D*>(this)[i]; }
  42 };
  43
  44 struct FatLine
  45 {
  46     // line L through p1 and p4 in normalized implicit form
  47     double a;
  48     double b;
  49     double c;
  50
  51     // the upper and lower distance from this line
  52     double dMin;
  53     double dMax;
  54 };
  55
  56 template <typename DataType> DataType calcLineDistance( const DataType& a,
  57                                                         const DataType& b,
  58                                                         const DataType& c,
  59                                                         const DataType& x,
  60                                                         const DataType& y )
  61 {
  62     return a*x + b*y + c;
  63 }
  64
  65 typedef std::vector< Point2D > Polygon2D;
  66
  67 /* little abs template */
  68 template <typename NumType> NumType absval( NumType x )
  69 {
  70     return x<0 ? -x : x;
  71 }
  72
  73 Polygon2D convexHull( const Polygon2D& rPoly );
  74
  75 // TODO: find proper epsilon here (try std::numeric_limits<NumType>::epsilon()?)!
  76 constexpr auto DBL_EPSILON = 1.0e-100;
  77
  78 /* little approximate comparisons */
  79 template <typename NumType> bool tolZero( NumType n ) { return fabs(n) < DBL_EPSILON; }
  80 template <typename NumType> bool tolEqual( NumType n1, NumType n2 ) { return tolZero(n1-n2); }
  81 template <typename NumType> bool tolLessEqual( NumType n1, NumType n2 ) { return tolEqual(n1,n2) || n1<n2; }
  82 template <typename NumType> bool tolGreaterEqual( NumType n1, NumType n2 ) { return tolEqual(n1,n2) || n1>n2; }
  83
  84 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */