{#
  Chrome diamond marker: white-filled rotated rect.
  Fill/stroke are supplied by the enclosing paradigm CSS class.
  Context: {x, y, size, half}.
#}
<rect x="{{ m.neg_half }}" y="{{ m.neg_half }}" width="{{ m.size }}" height="{{ m.size }}"
      transform="translate({{ m.x }} {{ m.y }}) rotate(45)"/>
