Constraining the dimension tool doesn't constrain the number shown

[Seth Hillbrand]

When adding a dimension to the pcb, you can use Ctrl to limit the axes used. However, the number shown before clicking uses the mouse cursor position rather than the constrained measurement position as its reference.

N.B. This also happens with the dimension tool

Application: kicad
Version: (5.0.0-rc3-dev-7-gc9c9245e7), release build
Libraries:
    wxWidgets 3.0.2
    libcurl/7.52.1 OpenSSL/1.0.2l zlib/1.2.8 libidn2/0.16 libpsl/0.17.0 (+libidn2/0.16) libssh2/1.7.0 nghttp2/1.18.1 librtmp/2.3
Platform: Linux 4.9.0-6-amd64 x86_64, 64 bit, Little endian, wxGTK
Build Info:
    wxWidgets: 3.0.2 (wchar_t,wx containers,compatible with 2.8) GTK+ 2.24
    Boost: 1.62.0
    OpenCASCADE Community Edition: 6.8.0
    Curl: 7.52.1
    Compiler: GCC 6.3.0 with C++ ABI 1010

Build settings:
    USE_WX_GRAPHICS_CONTEXT=OFF
    USE_WX_OVERLAY=OFF
    KICAD_SCRIPTING=ON
    KICAD_SCRIPTING_MODULES=ON
    KICAD_SCRIPTING_WXPYTHON=ON
    KICAD_SCRIPTING_ACTION_MENU=ON
    BUILD_GITHUB_PLUGIN=ON
    KICAD_USE_OCE=ON
    KICAD_USE_OCC=OFF
    KICAD_SPICE=ON

[John Beard (john-j-beard)]

For the dimension tool, this looks like DRAWING_TOOL::constrainDimension() only constrains the angle. If you watch closely, the length is still the hypotenuse to the mouse.

[John Beard (john-j-beard)]

Almost exactly the same thing in TWO_POINT_GEOMETRY_MANAGER::SetEnd(), which is what governs the measure tool geometry.

[John Beard (john-j-beard)]

This patch fixes this by using a snapping algorithm that keeps the new snapped vector on the grid.

[Jeff Young (jeyjey)]

@Seth, were you doing something here, or shall I test and merge John's patch?

[Seth Hillbrand (sethh)]

Yes, please do. Hasn't gotten to it yet

[KiCad Janitor (kicad-janitor)]

Fixed in revision 7acc0b89f9bbbd59365bc3845b2f3fa827d509e9
https://git.launchpad.net/kicad/patch/?id=7acc0b89f9bbbd59365bc3845b2f3fa827d509e9

[Jeff Young (jeyjey)]

I tested an merged your patch, John. Thanks for your contribution!