gEDA-dev: Switch all drawing variables into the world coordinate system

[Werner Hoch]

Hi there,

On Dienstag, 1. April 2008, Werner Hoch wrote:
> the magnetic net mode uncovered some integer arithmetic errors
> whenever the coordinates are changed between screen and world (e.g.
> with the fix_x() function).
> http://sourceforge.net/tracker/index.php?func=detail&aid=1928544&grou
>p_id=161080&atid=818426
>
> Thus I'd like to change the screen related variables from the screen
> coordinates to the world coordinates.
>
> The affected variables are start_x, second_x, last_x, loc_x and maybe
> some more.
>
> To do this I'd change this with the following steps:
>
> 1. create a set of world variables in GSCHEM_TOPLEVEL:
>    start_x -->  first_wx
>    last_x -->  second_wx
>    second_x --> third_wx
> The renaming is intentional, because the second_x causes confusions
> in the net code whenever I read it.
>
> 2. add world coordinates to all screen events (mouse move, ...)
>    SCREENtoWORLD(toplevel, x,y, &wx, &wy);
>    wx = snap_grid(toplevel, wx);
>    wy = snap_grid(toplevel, wy);
>
> 3. subsequently switch each drawing mode (net, line, box, ...) to use
>    the world coordinates.
>    (the coordinates are only converted back to screen inside drawing
>    functions)
>
> 4. remove the old variables:
>    start_x, last_x, ...
>
> 5. remove fix_x, fix_y functions from libgeda.

I've done the changes mentioned above. The complete branch is at
http://repo.or.cz/w/geda-gaf/werner.git?a=shortlog;h=refs/heads/world_coordinates

Please play a little bit with it.

This branch also contains 
 * the net_routing feature 
 * a CTRL modifier for magnetic net 
 * snapping to offgrid pins/nets with printing a warning when doing so

I will do some more testing next week. It would be nice if someone else 
could do some testing to.

I'd like to merge those changes in 3 steps to the official repo maybe 
next weekend.
1. net routing code (branch name: netrouting1)
2. magnetic net mode (branch name: world_netcoordinates)
3. all the rest (branch name: world_coordinates)

Regards
Werner