drawing graphic on a copper layer is not easy

[Thomas Pointhuber]

From my current knowledge, graphic items on copper is no longer a problem in the nighly, which means people can draw items on the copper layer. Unfortunately, users cannot really do this because the GUI still has some legacy behaviour which makes it impossible to directly draw graphics on the copper layer.

Example:

1. select graphic line tool
2. change layer to copper (F.Cu for example)
3. move the cursor to the drawing area. When it enters the canvas the layer is changed to F.SilkS automatically
4. user draws on F.SilkS instead of the selected F.Cu layer

# Version Information

Application: kicad
Version: (6.0.0-rc1-dev-698-gf2a49c6bd), debug build
Libraries:
    wxWidgets 3.1.1
    libcurl/7.61.1 OpenSSL/1.1.1 zlib/1.2.11 libidn2/2.0.5 libpsl/0.20.2 (+libidn2/2.0.4) libssh2/1.8.0 nghttp2/1.33.0
Platform: Linux 4.18.12-arch1-1-ARCH x86_64, 64 bit, Little endian, wxGTK
Build Info:
    wxWidgets: 3.1.1 (wchar_t,wx containers) GTK+ 2.24
    Boost: 1.68.0
    OpenCASCADE Community Edition: 6.9.1
    Curl: 7.61.1
    Compiler: Clang 7.0.0 with C++ ABI 1002

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

[jean-pierre charras (jp-charras)]

Graphic items on copper are never a good idea.
For instance you cannot define a clearance for these items
Therefore I am not sure making them easy to draw on copper layers is a good idea.

"graphic items on copper is no longer a problem in the nighly":

Not true: DRC detects clearance issues between a track/pad and a graphic item (this is good).
But therefore, now, net tie footprints always create DRC errors (this is annoying).

A good graphic item on copper layers management is not easy and is planned for the 6.0 version.

[KiCad Janitor (kicad-janitor)]

Fixed in revision 920d9e3d46f89dd60ed52553ab635a697227e21b
https://git.launchpad.net/kicad/patch/?id=920d9e3d46f89dd60ed52553ab635a697227e21b

[jean-pierre charras (jp-charras)]

@Jeff
I reopen this bug, because the fix creates *serious issues*:
Dimensions and polygons are now allowed on copper layers, but they are ignored by DRC and can create broken boards (short circuits).

This is a serious flaw:
at least dimensions should be *not* allowed (fully ignored by DRC and zone filling).
polygons should be taken in account by DRC, or not allowed.

[Wayne Stambaugh (stambaughw)]

The reason we haven't enabled this in the past is because the DRC doesn't handle it. I recommend we revert this change until the DRC is capable of handling dimensions and polygons on copper layers.

[KiCad Janitor (kicad-janitor)]

Fixed in revision 77284e82c821682cbd8bb9c9ac812664c4f60dfa
https://git.launchpad.net/kicad/patch/?id=77284e82c821682cbd8bb9c9ac812664c4f60dfa