libstdc++-v3/testsuite/26_numerics/lerp/1.cc

   1 // Copyright (C) 2019-2023 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // { dg-options "-std=gnu++2a" }
  19 // { dg-do run { target c++2a } }
  20
  21 #include <cmath>
  22
  23 #ifndef __cpp_lib_interpolate
  24 # error "Feature-test macro for midpoint and lerp missing in <cmath>"
  25 #elif __cpp_lib_interpolate != 201902L
  26 # error "Feature-test macro for midpoint and lerp has wrong value in <cmath>"
  27 #endif
  28
  29 #include <limits>
  30 #include <testsuite_hooks.h>
  31
  32 void
  33 test01()
  34 {
  35   using lim = std::numeric_limits<double>;
  36
  37   VERIFY( std::lerp(0.0, 1.0, 0.0) == 0.0 );
  38   VERIFY( std::lerp(-2.0, 10.0, 1.0) == 10.0 );
  39   VERIFY( std::lerp(2.0, -10.0, 1.0) == -10.0 );
  40   VERIFY( std::lerp(-8.0, 10.0, 0.5) == 1.0 );
  41   VERIFY( std::lerp(-10.0, 10.0, 0.25) == -5.0 );
  42   VERIFY( std::lerp(10.0, -10.0, 0.375) == 2.5 );
  43
  44   VERIFY( std::lerp(2.0, 2.0, 200.0) == 2.0 );
  45   VERIFY( std::lerp(2.0, 4.0, 200.0) == 402.0 );
  46   VERIFY( std::lerp(2.0, 4.0, -20.0) == -38.0 );
  47
  48   VERIFY( std::lerp(1.1, 30201.1, 0) == 1.1 );
  49   VERIFY( std::lerp(1.1, 30201.1, 1) == 30201.1 );
  50   VERIFY( std::lerp(1.1, -30201.1, 0) == 1.1 );
  51   VERIFY( std::lerp(1.1, -30201.1, 1) == -30201.1 );
  52
  53   VERIFY( std::lerp(1.1, 1.1, lim::infinity()) == 1.1 );
  54   VERIFY( std::isfinite(std::lerp(1.1, 1.1+lim::min(), lim::max())) );
  55
  56   VERIFY( std::lerp(lim::max(), lim::max(), 1) == lim::max() );
  57   VERIFY( std::lerp(lim::max(), lim::max()/9e9, 0) == lim::max() );
  58   VERIFY( std::lerp(lim::max()/9e9, lim::max(), 1) == lim::max() );
  59 }
  60
  61 void
  62 test02()
  63 {
  64   using lim = std::numeric_limits<float>;
  65
  66   VERIFY( std::lerp(0.0f, 1.0f, 0.0f) == 0.0f );
  67   VERIFY( std::lerp(-2.0f, 10.0f, 1.0f) == 10.0f );
  68   VERIFY( std::lerp(2.0f, -10.0f, 1.0f) == -10.0f );
  69   VERIFY( std::lerp(-8.0f, 10.0f, 0.5f) == 1.0f );
  70   VERIFY( std::lerp(-10.0f, 10.0f, 0.25f) == -5.0f );
  71   VERIFY( std::lerp(10.0f, -10.0f, 0.375f) == 2.5f );
  72
  73   VERIFY( std::lerp(2.0f, 2.0f, 200.0f) == 2.0f );
  74   VERIFY( std::lerp(2.0f, 4.0f, 200.0f) == 402.0f );
  75   VERIFY( std::lerp(2.0f, 4.0f, -20.0f) == -38.0f );
  76
  77   VERIFY( std::lerp(1.1f, 30201.1f, 0) == 1.1f );
  78   VERIFY( std::lerp(1.1f, 30201.1f, 1) == 30201.1f );
  79   VERIFY( std::lerp(1.1f, -30201.1f, 0) == 1.1f );
  80   VERIFY( std::lerp(1.1f, -30201.1f, 1) == -30201.1f );
  81
  82   VERIFY( std::lerp(1.1f, 1.1f, lim::infinity()) == 1.1f );
  83   VERIFY( std::isfinite(std::lerp(1.1f, 1.1f+lim::min(), lim::max())) );
  84
  85   VERIFY( std::lerp(lim::max(), lim::max(), 1) == lim::max() );
  86   VERIFY( std::lerp(lim::max(), lim::max()/9e9f, 0) == lim::max() );
  87   VERIFY( std::lerp(lim::max()/9e9f, lim::max(), 1) == lim::max() );
  88 }
  89
  90 void
  91 test03()
  92 {
  93   using lim = std::numeric_limits<long double>;
  94
  95   VERIFY( std::lerp(0.0l, 1.0l, 0.0l) == 0.0l );
  96   VERIFY( std::lerp(-2.0l, 10.0l, 1.0l) == 10.0l );
  97   VERIFY( std::lerp(2.0l, -10.0l, 1.0l) == -10.0l );
  98   VERIFY( std::lerp(-8.0l, 10.0l, 0.5l) == 1.0l );
  99   VERIFY( std::lerp(-10.0l, 10.0l, 0.25l) == -5.0l );
 100   VERIFY( std::lerp(10.0l, -10.0l, 0.375l) == 2.5l );
 101
 102   VERIFY( std::lerp(2.0l, 2.0l, 200.0l) == 2.0l );
 103   VERIFY( std::lerp(2.0l, 4.0l, 200.0l) == 402.0l );
 104   VERIFY( std::lerp(2.0l, 4.0l, -20.0l) == -38.0l );
 105
 106   VERIFY( std::lerp(1.1l, 30201.1l, 0) == 1.1l );
 107   VERIFY( std::lerp(1.1l, 30201.1l, 1) == 30201.1l );
 108   VERIFY( std::lerp(1.1l, -30201.1l, 0) == 1.1l );
 109   VERIFY( std::lerp(1.1l, -30201.1l, 1) == -30201.1l );
 110
 111   VERIFY( std::lerp(1.1l, 1.1l, lim::infinity()) == 1.1l );
 112   VERIFY( std::isfinite(std::lerp(1.1l, 1.1l+lim::min(), lim::max())) );
 113
 114   VERIFY( std::lerp(lim::max(), lim::max(), 1) == lim::max() );
 115   VERIFY( std::lerp(lim::max(), lim::max()/9e9l, 0) == lim::max() );
 116   VERIFY( std::lerp(lim::max()/9e9l, lim::max(), 1) == lim::max() );
 117 }
 118
 119 int main()
 120 {
 121   test01();
 122   test02();
 123   test03();
 124 }