text: 
  //
  // This source file is part of appleseed.
  // Visit https://appleseedhq.net/ for additional information and resources.
  //
  // This software is released under the MIT license.
  //
  // Copyright (c) 2010-2013 Francois Beaune, Jupiter Jazz Limited
  // Copyright (c) 2014-2018 Francois Beaune, The appleseedhq Organization
  //
  // Permission is hereby granted, free of charge, to any person obtaining a copy
  // of this software and associated documentation files (the "Software"), to deal
  // in the Software without restriction, including without limitation the rights
  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  // copies of the Software, and to permit persons to whom the Software is
  // furnished to do so, subject to the following conditions:
  //
  // The above copyright notice and this permission notice shall be included in
  // all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  // THE SOFTWARE.
  //
  
  // appleseed.renderer headers.
  #include "renderer/kernel/rendering/final/pixelsampler.h"
  
  // appleseed.foundation headers.
  #include "foundation/math/vector.h"
  #include "foundation/utility/iostreamop.h"
  #include "foundation/utility/test.h"
  
  // Standard headers.
  #include <cstddef>
  
  using namespace foundation;
  using namespace renderer;
  
  TEST_SUITE(Renderer_Kernel_Rendering_Final_PixelSampler)
  {
      template <size_t SubpixelGridSize>
      struct Fixture
      {
          PixelSampler m_sampler;
  
          Fixture()
          {
              m_sampler.initialize(SubpixelGridSize);
          }
      };
  
      TEST_CASE_F(Sample_SubpixelGridSizeIs1x1_ReturnsSampleAtCenterOfPixel, Fixture<1>)
      {
          Vector2d sample_position;
          size_t initial_instance;
          m_sampler.sample(13, 17, sample_position, initial_instance);
  
          EXPECT_EQ(Vector2d(13.5, 17.5), sample_position);
      }
  
      TEST_CASE_F(Sample_SubpixelGridSizeIs2x2_SubpixelAtTopLeftCorner, Fixture<2>)
      {
          Vector2d sample_position;
          size_t initial_instance;
          m_sampler.sample(0, 0, sample_position, initial_instance);
  
          EXPECT_EQ(Vector2d(0.0), sample_position);
      }
  
      TEST_CASE_F(Sample_SubpixelGridSizeIs2x2_SubpixelAtBottomRightCorner, Fixture<2>)
      {
          // Assume a 32x32 pixels image with 2x2 samples per pixels.
          Vector2d sample_position;
          size_t initial_instance;
          m_sampler.sample(32 * 2 - 1, 32 * 2 - 1, sample_position, initial_instance);
  
          EXPECT_EQ(Vector2d(31.9921875), sample_position);
      }
  }
  