pj_zpoly1.hpp 3.6 KB

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  1. // Boost.Geometry (aka GGL, Generic Geometry Library)
  2. // This file is manually converted from PROJ4
  3. // Copyright (c) 2008-2012 Barend Gehrels, Amsterdam, the Netherlands.
  4. // This file was modified by Oracle on 2017, 2018.
  5. // Modifications copyright (c) 2017-2018, Oracle and/or its affiliates.
  6. // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
  7. // Use, modification and distribution is subject to the Boost Software License,
  8. // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  9. // http://www.boost.org/LICENSE_1_0.txt)
  10. // This file is converted from PROJ4, http://trac.osgeo.org/proj
  11. // PROJ4 is originally written by Gerald Evenden (then of the USGS)
  12. // PROJ4 is maintained by Frank Warmerdam
  13. // PROJ4 is converted to Geometry Library by Barend Gehrels (Geodan, Amsterdam)
  14. // Original copyright notice:
  15. // Permission is hereby granted, free of charge, to any person obtaining a
  16. // copy of this software and associated documentation files (the "Software"),
  17. // to deal in the Software without restriction, including without limitation
  18. // the rights to use, copy, modify, merge, publish, distribute, sublicense,
  19. // and/or sell copies of the Software, and to permit persons to whom the
  20. // Software is furnished to do so, subject to the following conditions:
  21. // The above copyright notice and this permission notice shall be included
  22. // in all copies or substantial portions of the Software.
  23. // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  24. // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  25. // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  26. // THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  27. // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  28. // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  29. // DEALINGS IN THE SOFTWARE.
  30. #ifndef BOOST_GEOMETRY_PROJECTIONS_ZPOLY1_HPP
  31. #define BOOST_GEOMETRY_PROJECTIONS_ZPOLY1_HPP
  32. #include <boost/geometry/srs/projections/impl/projects.hpp>
  33. namespace boost { namespace geometry { namespace projections { namespace detail {
  34. /* evaluate complex polynomial */
  35. /* note: coefficients are always from C_1 to C_n
  36. ** i.e. C_0 == (0., 0)
  37. ** n should always be >= 1 though no checks are made
  38. */
  39. template <typename T>
  40. inline pj_complex<T>
  41. pj_zpoly1(pj_complex<T> z, const pj_complex<T> *C, int n)
  42. {
  43. pj_complex<T> a;
  44. T t;
  45. a = *(C += n);
  46. while (n-- > 0)
  47. {
  48. a.r = (--C)->r + z.r * (t = a.r) - z.i * a.i;
  49. a.i = C->i + z.r * a.i + z.i * t;
  50. }
  51. a.r = z.r * (t = a.r) - z.i * a.i;
  52. a.i = z.r * a.i + z.i * t;
  53. return a;
  54. }
  55. /* evaluate complex polynomial and derivative */
  56. template <typename T>
  57. inline pj_complex<T>
  58. pj_zpolyd1(pj_complex<T> z, const pj_complex<T> *C, int n, pj_complex<T> *der)
  59. {
  60. T t;
  61. bool first = true;
  62. pj_complex<T> a = *(C += n);
  63. pj_complex<T> b = a;
  64. while (n-- > 0)
  65. {
  66. if (first)
  67. {
  68. first = false;
  69. }
  70. else
  71. {
  72. b.r = a.r + z.r * (t = b.r) - z.i * b.i;
  73. b.i = a.i + z.r * b.i + z.i * t;
  74. }
  75. a.r = (--C)->r + z.r * (t = a.r) - z.i * a.i;
  76. a.i = C->i + z.r * a.i + z.i * t;
  77. }
  78. b.r = a.r + z.r * (t = b.r) - z.i * b.i;
  79. b.i = a.i + z.r * b.i + z.i * t;
  80. a.r = z.r * (t = a.r) - z.i * a.i;
  81. a.i = z.r * a.i + z.i * t;
  82. *der = b;
  83. return a;
  84. }
  85. }}}} // namespace boost::geometry::projections::detail
  86. #endif