It may be too late, but I found another good reference on Wikipedia: it appears that AM was basically describing the Meandering Triangle variant of the Marching Squares algorithm.

To handle the case of vertices being equal, that article uses isobands instead of isobars (contour lines): label each point in the triangle (0 for points less than your level, 1 for points equal to your level, and 2 for points greater than your level), and then follow their lookup table for the shape of the isoband.

In reply to Re^6: Contour mapping? (Thank Dog for anonymonk.) by pryrt
in thread Contour mapping? by BrowserUk

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