Module shapes 

Shape generators – create geographic geometries from parameters

Generate common geometric shapes as GeoCoord rings suitable for use with the tessellator, vector layers, or direct rendering:

• circle – regular polygon approximating a circle
• arc – partial circle (sector boundary)
• ellipse – elliptical ring
• rectangle – axis-aligned geographic rectangle
• regular_polygon – equilateral N-gon
• sector – pie-slice shape (arc closed to centre)
• line_along – sample points along a great-circle path

All generators produce Vec<GeoCoord> suitable for constructing Polygon exteriors or LineString coordinates.

Distance calculations use the geodesic destination formula on the WGS-84 sphere (radius 6,378,137 m).

Functions

arc

Generate an arc (partial circle) as a polyline.

circle

Generate a circle as a closed polygon ring.

ellipse

Generate an ellipse as a closed polygon ring.

line_along

Sample count evenly-spaced points along the great-circle path between from and to.

rectangle

Generate an axis-aligned geographic rectangle as a closed polygon ring.

regular_polygon

Generate a regular N-gon as a closed polygon ring.

sector

Generate a sector (pie slice) as a closed polygon ring.