Editor: Add button to flip vertically

[SimonN]

namida42: is it just me, or is there no "flip horizontal" option? Or vertical. one appears to be missing. Proxima_: Flip then rotate twice. SimonNa: this needs high-level math and not everybody will see this, it's probably okay to add a button. The UI is too dependent on the internal representation, which has only one flip flag. Every UI of graphics programs allows flip horz, flip vert, and rotate.

namida42: by the way, a glaring UI problem: the "flip piece" button has an icon that indicates vertical flip, but a description that indicates horizontal flip. Whether the description is correct depends on "is the piece rotated or not?"

[SimonN]

I will draw a mirror-horizontal button instead of the wrong flip-vertical button. This will be done and released by Sunday night, September 23rd.

Unsure whether to add a flip-vertical button, it's probably better to make one.

[SimonN]

Discussion on LF: Add button to flip vertically to editor?

Yes, let's add the button. Graphics software would look incomplete if it offered only one button of the two. Lix should follow basic UI principles. Lix shouldn't require everybody to know that (mirror, rotate, rotate) is the same as mirroring along the other axis.

[SimonN]

Added button to flip vertically in 0.10.1.