static_transform_rgb_to_cmyk_fail.cpp 1.3 KB

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  1. //
  2. // Copyright 2019 Mateusz Loskot <mateusz at loskot dot net>
  3. //
  4. // Distributed under the Boost Software License, Version 1.0
  5. // See accompanying file LICENSE_1_0.txt or copy at
  6. // http://www.boost.org/LICENSE_1_0.txt
  7. //
  8. #include <boost/gil/color_base_algorithm.hpp>
  9. #include <boost/gil/pixel.hpp>
  10. #include <boost/gil/typedefs.hpp>
  11. #include <cassert>
  12. #include <cstdint>
  13. namespace gil = boost::gil;
  14. int main()
  15. {
  16. // K-element index must be less than size of channel_mapping_t sequence
  17. // of the *destination* color base.
  18. // RGB (wider space) transformation to Gray (narrower space) takes only R channel value
  19. {
  20. gil::cmyk8_pixel_t src{16, 32, 64, 128};
  21. gil::rgb8_pixel_t dst{0, 0, 0};
  22. gil::static_transform(src, dst, [](std::uint8_t src_channel) {
  23. return src_channel; // copy
  24. });
  25. assert(gil::at_c<0>(dst) == std::uint16_t{16});
  26. assert(gil::at_c<0>(dst) == std::uint16_t{32});
  27. assert(gil::at_c<0>(dst) == std::uint16_t{64});
  28. }
  29. // RGB (narrower space) to CMYK (wider space) transformation FAILS to compile
  30. {
  31. gil::rgb8_pixel_t src{16, 32, 64};
  32. gil::cmyk8_pixel_t dst{0, 0, 0, 0};
  33. gil::static_transform(src, dst, [](std::uint8_t src_channel) {
  34. return src_channel; // copy
  35. });
  36. }
  37. }