dxf files emerge from various applications, for example Autocad, LibreCAD and so on. Sometimes a design should be flexible, e.g. one should be able to change one dimension of it and keep everything intact after such a change. This of course would require to parametrise everything from the very beginning, e.g.
- Points may be either fixed or related to other points by given distances and directions or how they were geometrically constructed as intersections between other previously defined entities.
- Lines become connections between points defined before or parallel to some other line with a given distance, at a given angle to an existing line and so on. Lines crossing other lines define intersection points once they are used in a construction.
- Circles depend on points (center) and radii or intersection properties, being tangent to some line(s) and so on.
- Whole sub-designs would be defined by how they were constructed and then copied, mirrored, arranged at other orientations and so on.
- If one would continue to 3D, volumes are created as spheres, bricks and other elementary bodies or as extrusions from 2d shapes constructed before.
So my question becomes: Is the dxf file format restricted on points being individually given as numerical coordinates and lines being defined by their end points only? How far is it open for relations where the actual values can be adapted later to some other numerical value and can the dependence of those entities be represented in an dxf file?
Is there a free open source 2D CAD program which supports a parametric paradigm?
