Draw a maple leaf using Oracle Spatial

Natalka asked if I can make a maple leaf with Oracle Spatial.

The most basic way to draw any polygon with Oracle Spatial is to”

  1. Plot the shape on a graph.
  2. Add the grid coordinates to a polygon SDO_GEOMETRY object. Remember to go in a counter-clockwise direction.

For a maple leaf, I searched duckduckgo.com for a bit and found a very detailed grid mapping of a maple leaf.

The points in that doc are ordered in a clockwise direction, so I reversed the order and added them to an SDO_ORDINATE_ARRAY which generates the following.


It’s a nice leaf but not quite Canadian enough.

I was unable to find a complete mapping of a leaf closer to the Canadian flag, so I found several examples that were all similar but incomplete, and did my best to guess at the missing data.

I started at the top point and worked my way counter-clockwise around the leaf points to the bottom left stem point.

Since I centered it on the 0 x axis I simply removed the negative from the x ordinates, reversed the order of the coordinates and added them to the SDO_ORDINATE_ARRAY.  Notice the start and end points are the same to close the polygon.

After checking that the object is valid using .st_isvalid() I generated this leaf.


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