Render queued streamplot arrows after plot lines are drawn. Uses draw_arrowhead (head-only glyph) so a normalized direction vector does not get scaled into a data-coord shaft like draw_arrow does for quiver.
The text backend routes each arrowhead through the cell layer policy (LAYER_DATA), so a direction marker occupies its plot cell without overwriting axes, ticks, or tick/axis labels (issue #2070). Raster and vector backends render the arrowhead geometry unchanged.
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| class(plot_context), | intent(inout) | :: | backend | |||
| type(arrow_data_t), | intent(in) | :: | arrows(:) |