Renders a flat top-down image of the map using terrain colors.
Returns a Blob (PNG by default) suitable for download, a saved thumbnail,
or passing to URL.createObjectURL.
For a minimap that updates as the map is edited, use drawMapImage
against a visible canvas instead — it skips the encode/decode round trip.
Renders a flat top-down image of the map using terrain colors. Returns a
Blob(PNG by default) suitable for download, a saved thumbnail, or passing toURL.createObjectURL.For a minimap that updates as the map is edited, use drawMapImage against a visible canvas instead — it skips the encode/decode round trip.