Function SaveEXRToMemory

third-party/tinyexr/tinyexr.h:9010–9158

}

int SaveEXRToMemory(const float *data, int width, int height, int components,
            const int save_as_fp16, unsigned char **outbuf, 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];

  if (components == 1) {
    images[0].resize(static_cast<size_t>(width * height));
    memcpy(images[0].data(), data, sizeof(float) * size_t(width * height));
  } else {
    images[0].resize(static_cast<size_t>(width * height));
    images[1].resize(static_cast<size_t>(width * height));
    images[2].resize(static_cast<size_t>(width * height));
    images[3].resize(static_cast<size_t>(width * height));

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

  float *image_ptr[4] = {0, 0, 0, 0};
  if (components == 4) {
    image_ptr[0] = &(images[3].at(0));  // A
    image_ptr[1] = &(images[2].at(0));  // B
    image_ptr[2] = &(images[1].at(0));  // G
    image_ptr[3] = &(images[0].at(0));  // R
  } else if (components == 3) {
    image_ptr[0] = &(images[2].at(0));  // B