Support unit of measure for render gears and render gear rack plugins

[Anton]

Hello,

Currently Render gears (and Render gears rack, which I can see appeared in trunk) only allow to provide size parameters in pixels. It would be nice if they allow to provide parameters in any units (physical units like millimeters are useful for CNC).

Plugin files in trunk:
http://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/view/head:/share/extensions/render_gear_rack.inx
http://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/view/head:/share/extensions/render_gear_rack.py
http://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/view/head:/share/extensions/render_gears.inx
http://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/view/head:/share/extensions/render_gears.py

I have implemented this in my own repository (fixed "generate gears" plugin from current stable 0.48, render rack and pinion based on the same "generate gears"):

https://github.com/1i7/metalrobot/blob/master/inkscape/extensions/rack_and_pinion.inx
https://github.com/1i7/metalrobot/blob/master/inkscape/extensions/rack_and_pinion.py
https://github.com/1i7/metalrobot/blob/master/inkscape/extensions/gears1.inx
https://github.com/1i7/metalrobot/blob/master/inkscape/extensions/gears1.py

To add unit of measure take 2 steps:

1) add "Unit" param to inx file:

 <param name="unit" type="optiongroup" appearance="minimal" _gui-text="Unit">
<option value="cm">cm</option>
<option value="ft">ft</option>
<option value="in">in</option>
<option value="m">m</option>
<option value="mm">mm</option>
<option value="pc">pc</option>
<option value="pt">pt</option>
<option value="px">px</option>
</param>

2) then in Python file add unit param to OptionParser

 self.OptionParser.add_option("-u", "--unit",
action="store", type="string",
dest="unit", default="px",
help="The unit of dimensions")

and init other params using this unit in the following way:

 pitch = inkex.unittouu( str(self.options.pitch) + self.options.unit )

With this I have gears and rack and pinion plugins, that can generate details in millimeters in Inkscape 0.48

To test plugins with current Inkscape installation put inx and py files to
- on Windows: C:\Users\user\AppData\Roaming\inkscape\extensions
- on Linux: ~/.config/inkscape/extensions

and restart Inkscape, then go to menu "Extensions/Render/Gear1..." or "Extensions/Render/Rack and pinion...".

[su_v (suv-lp)]

There are no further bug-fix releases of Inkscape 0.48.x planned.

> pitch = inkex.unittouu( str(self.options.pitch) + self.options.unit )

Please note: using 'inkex.unittouu()' is not compatible with trunk or upcoming 0.91 [1].

Any chance you could coordinate your proposed changes with the author of this (likely) related request?
- Bug #1295641 “gears-dev -- an improved version of the gears extension”
  <https://bugs.launchpad.net/inkscape/+bug/1295641>

--
[1] http://wiki.inkscape.org/wiki/index.php/Release_notes/0.91#Units:_Breaking_change

[Anton (benderamp)]

Thank's for pointing, as far, as I can see, this gears-dev project already has unit parameters inside its inx config files.

[Neon22 (neon22)]

Yes - gears-dev does do this much better.

This issue could probably be closed.

Ideally gears-dev could be distributed instead of gears. However new addons page on inkscape.org website does allow easier access to all user made extensions.