kicad-developers team mailing list archive

[Simon Richter <Simon.Richter@xxxxxxxxxx>]

Hi,

On Fri, Jun 21, 2019 at 10:54:04PM -0400, Reece R. Pollack wrote:

> Just for discussion, let's assume the replacement for wxPoint is
> named KiPoint. The result of subtracting two KiPoint objects would
> be another object called KiDelta. Adding two KiPoint objects should
> be undefined, and result in a compile-time error, as this is a
> nonsense operation.

I have something like that cooking in my "units" branch, but I'm cleaning
up angles first.

Plan:

 - create strong types for angles and orientations [done]
 - literal handling with unit suffix [done]
 - replace all instances of angles in the codebase [under way]
 - drop code to support angles expressed as doubles, ints, ...

Replacing points will be too big to do in a single commit, so:

 - create strong types for lengths and points [needs rework]
 - literal handling with unit suffix [mostly done]
 - compatibility code for automatic conversion to existing formats [mostly
   done]
 - piecewise replacement of existing coordinate code
 - remove compatibility code
 - remove old code
 - remove -DEESCHEMA, -DPCBNEW etc.
 - merge pcbcommon into common

The way I went with my approach was that there is a length class that
expresses a 1D length in either nanometers. A separate class does the same
for pixels.

2D coordinates have a template parameter for the underlying 1D type, and
for the origin point they are relative to:

 - no origin
 - (0, 0)
 - current reference (set with the space bar)
 - auxiliary axis (set with the aux axis tool)

Adding and subtracting then makes sure origin points are consistent, and
multiplying with the current zoom level converts between world and screen
coordinates.

The initial implementation went a bit wrong because the angle handling
needs to be done first -- the transition requires adding a new coordinate
type parallel to the existing ones, which also requires a full set of
Rotate* functions (degrees as double, tenth-degrees as double,
tenth-degrees as signed int, radians as double), so reducing all of these
to one makes this manageable.

   Simon