Function plot_axis_horizontal

src/plot/axis.cc:409–545

}

static ReturnCode plot_axis_horizontal(
    Context* ctx,
    PlotConfig* plot,
    const AxisDefinition& axis_config,
    double y,
    double x0,
    double x1) {
  /* draw axis line */
  draw_line(ctx, {x0, y}, {x1, y}, axis_config.border_style);

  /* draw ticks */
  ScaleLayout ticks;
  axis_config.tick_placement(
      axis_config.scale,
      axis_config.label_formatter,
      &ticks);

  double tick_position =
      std::clamp(axis_config.tick_offset, -1.0, 1.0);

  auto tick_length = measure_or(
      axis_config.tick_length,
      from_pt(kDefaultTickLengthPT, layer_get_dpi(ctx)));

  for (const auto& tick : ticks.positions) {
    auto ty = y - tick_length + tick_length * (tick_position + 1) / 2.0;
    auto tx = x0 + (x1 - x0) * tick;
    draw_line(
        ctx,
        {tx, ty},
        {tx, ty + tick_length},
        axis_config.border_style);
  }

  /* draw labels */
  ScaleLayout labels;
  axis_config.label_placement(
      axis_config.scale,
      axis_config.label_formatter,
      &labels);

  double label_position =
      std::clamp(axis_config.label_offset, -1.0, 1.0);

  double label_padding =  measure_or(
      axis_config.label_padding,
      from_em(kDefaultLabelPaddingEM, axis_config.label_font_size));

  double label_size = 0;
  if (auto rc = axis_layout_labels(axis_config, ctx, &label_size); !rc) {
    return rc;
  }

  for (size_t i = 0; i < labels.positions.size(); ++i) {
    auto tick = labels.positions[i];
    auto label_text = labels.labels[i];

    Point p;