Function SaveEXR

tutorials/common/image/tinyexr.h:9255–9397

}

int SaveEXR(const float *data, int width, int height, int components,
            const int save_as_fp16, const char *outfilename, const char **err) {
  if ((components == 1) || components == 3 || components == 4) {
    // OK
  } else {
    std::stringstream ss;
    ss << "Unsupported component value : " << components << std::endl;

    tinyexr::SetErrorMessage(ss.str(), err);
    return TINYEXR_ERROR_INVALID_ARGUMENT;
  }

  EXRHeader header;
  InitEXRHeader(&header);

  if ((width < 16) && (height < 16)) {
    // No compression for small image.
    header.compression_type = TINYEXR_COMPRESSIONTYPE_NONE;
  } else {
    header.compression_type = TINYEXR_COMPRESSIONTYPE_ZIP;
  }

  EXRImage image;
  InitEXRImage(&image);

  image.num_channels = components;

  std::vector<float> images[4];
  const size_t pixel_count =
      static_cast<size_t>(width) * static_cast<size_t>(height);

  if (components == 1) {
    images[0].resize(pixel_count);
    memcpy(images[0].data(), data, sizeof(float) * pixel_count);
  } else {
    images[0].resize(pixel_count);
    images[1].resize(pixel_count);
    images[2].resize(pixel_count);
    images[3].resize(pixel_count);

    // Split RGB(A)RGB(A)RGB(A)... into R, G and B(and A) layers
    if (components == 4) {
       for (size_t i = 0; i < pixel_count; i++) {
         images[0][i] = data[static_cast<size_t>(components) * i + 0];
         images[1][i] = data[static_cast<size_t>(components) * i + 1];
         images[2][i] = data[static_cast<size_t>(components) * i + 2];
         images[3][i] = data[static_cast<size_t>(components) * i + 3];
       }
    } else {
       for (size_t i = 0; i < pixel_count; i++) {
         images[0][i] = data[static_cast<size_t>(components) * i + 0];
         images[1][i] = data[static_cast<size_t>(components) * i + 1];
         images[2][i] = data[static_cast<size_t>(components) * i + 2];
       }
    }
  }

  float *image_ptr[4] = {0, 0, 0, 0};