#440 Problems winth "Draw a tangential Circle ot three lines/arc/circles" when using lines


I found condition when circle is drawn in wrong place and size (file "problem_a.dxf") or I cannot draw that circle (file "problem_b.dxf").
What I want: circle which is tangential to three lines and which is placed at left side of lines.

Linux 3.11.0-13-generic 64bit Kubuntu 13.10

Version: master
SCM Revision: 2.0.0rc2
Compiler: GNU GCC 4.8.1
Qt Version: 4.8.4
Compiled on: Sep 17 2013

2 Attachments


  • LordOfBikes

    LordOfBikes - 2013-11-23
    • status: open --> open-accepted
    • Group: 1.0 --> 2.0
  • Dongxu Li

    Dongxu Li - 2013-11-28

    when there are multiple tangential circles, it's better to draw them all in preview and allow user to select with ease.

    right now, user has to move the mouse pointer around to try luck.

  • Dongxu Li

    Dongxu Li - 2013-11-29

    pushed a fix in master, commit a12ee77

    Please use the feature "Circle Tangential 3" instead of "Inscribed circle" for the time being.

    We will try to fix the inscribed circle later, but for the time being, Circle Tangential 3 was designed to handle 3 entities of arbitrary combination of types (arc/circle) and lines. In other words, you can draw a tangential circle of (3 lines), (two lines, one circle), (one line, two circles), or (3 circles).

    We should clean up the equation solver underneath:

    more robust:

    cubic solver
    quartic solver
    simultaneous quadratic solver

    there's no "God algorithm" for tolerance handling, but we may have to optimize more.

  • Dongxu Li

    Dongxu Li - 2013-11-29
    • status: open-accepted --> open-fixed
  • Dongxu Li

    Dongxu Li - 2013-12-01

    pushed a fix for a typo in master, commit: 61320ca..397dff2

    Please help testing

  • Valdas Jankūnas

    Compiled LibreCad from Git (Version: master; SCM Revision: 2.0.0rc3-16-g4dea68c; Compiler: GNU GCC 4.8.1; Qt Version: 4.8.4).

    Both test cases works without problems.


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