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 #ifndef INCLUDED_BASEGFX_SOURCE_WORKBENCH_BEZIERCLIP_HXX
  21 #define INCLUDED_BASEGFX_SOURCE_WORKBENCH_BEZIERCLIP_HXX
  22
  23 #include <vector>
  24
  25 struct Point2D
  26 {
  27     typedef double value_type;
  28     Point2D( double _x, double _y ) : x(_x), y(_y) {}
  29     Point2D() : x(), y() {}
  30     double x;
  31     double y;
  32 };
  33
  34 struct Bezier
  35 {
  36     Point2D p0;
  37     Point2D p1;
  38     Point2D p2;
  39     Point2D p3;
  40
  41     Point2D&        operator[]( int i ) { return reinterpret_cast<Point2D*>(this)[i]; }
  42     const Point2D&  operator[]( int i ) const { return reinterpret_cast<const Point2D*>(this)[i]; }
  43 };
  44
  45 struct FatLine
  46 {
  47     // line L through p1 and p4 in normalized implicit form
  48     double a;
  49     double b;
  50     double c;
  51
  52     // the upper and lower distance from this line
  53     double dMin;
  54     double dMax;
  55 };
  56
  57 template <typename DataType> DataType calcLineDistance( const DataType& a,
  58                                                         const DataType& b,
  59                                                         const DataType& c,
  60                                                         const DataType& x,
  61                                                         const DataType& y )
  62 {
  63     return a*x + b*y + c;
  64 }
  65
  66 typedef ::std::vector< Point2D > Polygon2D;
  67
  68 /* little abs template */
  69 template <typename NumType> NumType absval( NumType x )
  70 {
  71     return x<0 ? -x : x;
  72 }
  73
  74 Polygon2D convexHull( const Polygon2D& rPoly );
  75
  76 // TODO: find proper epsilon here (try ::std::numeric_limits<NumType>::epsilon()?)!
  77 #define DBL_EPSILON 1.0e-100
  78
  79 /* little approximate comparisons */
  80 template <typename NumType> bool tolZero( NumType n ) { return fabs(n) < DBL_EPSILON; }
  81 template <typename NumType> bool tolEqual( NumType n1, NumType n2 ) { return tolZero(n1-n2); }
  82 template <typename NumType> bool tolLessEqual( NumType n1, NumType n2 ) { return tolEqual(n1,n2) || n1<n2; }
  83 template <typename NumType> bool tolGreaterEqual( NumType n1, NumType n2 ) { return tolEqual(n1,n2) || n1>n2; }
  84
  85 #endif // INCLUDED_BASEGFX_SOURCE_WORKBENCH_BEZIERCLIP_HXX
  86
  87 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */