line/curve annotations

how about an option for annotations that are equivalent to GL_LINE_STRIP, a series of N points connected by lines; these could be used for highlighting features like cables, tracks, curb edges, whatever

Start by locating how the LabelMe annotation tool represents and renders its existing annotation types. Compare the requested GL_LINE_STRIP-style series of connected points with those types, then define the data, editing, rendering, and export behavior needed for line and curve annotations.

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