Technical Drawing in Elm

This package is built on top of the typed-svg package in Elm. It provides its own affine transformation stack which tracks local-to-world and world-to-local coordinate transformations. This allows:

• Easy transformation of mouse events to local coordinates.
• Geometry expressed in the local coordinate system.
• Consistent global line widths.
• Shortening paths to accommodate arrow heads.

This is implemented as a tree of nodes which are interpreted at render time to svg nodes.

Tooling Notes

Use elm-test and elm-verity-examples for testing:

elm-test
elm-verify-examples --run-tests

For local documentation preview, use elm-doc-preview

elm-doc-preview

TODO

• Capture L2W transformation when events are declared, not when they are attached to objects.
• Text.
• "Bake" node.
• Refactor to separate out styles and events stuff from the huge main file.
• Use a non-recursive traversal of the graph.
• Need a way to draw items in world coordinates.
• Arrow heads.
• More examples.