draw knights moves using right-angled arrows

[tewhalen]

Because I am a beginner at chess, it's easier for me to understand what's going on when arrows depicting a knight's move are drawn using right angles. I whipped up a patch that does this (and because I am not very good at math, I off-loaded some of the calculations onto the svg renderer). See attached image.

[niklasf]

Thanks for the pull request. The rendered result looks pretty good. A couple of comments:

• Please don't make changes to the coding style of the surrounding lines. It makes it hard to spot the actual changes. Instead, adjust your own additions to the surrounding coding style.
• I like the right-angled style, but I don't think it should be default. Arrows by (2, 1) are not guaranteed to be knight moves, semantically. Instead, shape or style could be a property of Arrow, similar to color.
• The transforms appear to be SVG Tiny compatible. We should double check that, though.

[sshivaji]

Wanted to point out that the bishop move is incorrect, it's not diagonal in the diagram. Am sure this is probably minor.

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On Mon, Dec 14, 2020, 7:51 AM Niklas Fiekas ***@***.***> wrote: Thanks for the pull request. The rendered result looks pretty good. A couple of comments: - Please don't make changes to the coding style of the surrounding lines. It makes it hard to spot the actual changes. Instead, adjust your own additions to the surrounding coding style. - I like the right-angled style, but I don't think it should be default. Arrows by (2, 1) are not guaranteed to be knight moves, semantically. Instead, shape or style could be a property of Arrow, similar to color. - The transforms appear to be SVG Tiny compatible. We should double check that, though. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#710 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAK5IGXDGFNXRG5PMPARZ3TSUYX6XANCNFSM4UZ3AXVA> .

[tewhalen]

Wanted to point out that the bishop move is incorrect, it's not diagonal in the diagram. Am sure this is probably minor.

Yeah, that's a D5 -> G3 arrow, not intended to indicate a bishop's move.

* Please don't make changes to the coding style of the surrounding lines. It makes it hard to spot the actual changes. Instead, adjust your own additions to the surrounding coding style.

Sorry about that – the perils of relying on black for formatting help.

* I like the right-angled style, but I don't think it should be default. Arrows by `(2, 1)` are not guaranteed to be knight moves, semantically. Instead, `shape` or `style` could be a property of `Arrow`, similar to `color`.

That makes sense. I'll see if I can revise to make the arrow style selectable. I'm still learning the ins and outs of SVG, so I made the whole arrow (line + head) a polygon, which perhaps is not the right move, since it will be harder to style. I'll see about switching the lines back to lines or polylines and making the arrow head a marker.

* The transforms appear to be SVG Tiny compatible. We should double check that, though.

Hrrrm, I wasn't aware that was the target - I'll see if I can find a validator and check the output.

[niklasf]

Sounds good. I don't mind the line/polygon decision. Whichever is easier to implement.