Fix field names in Transform

[artemisSystem]

Transform currently looks like this:

type Transform =
  { m11 :: Number
  , m12 :: Number
  , m21 :: Number
  , m22 :: Number
  , m31 :: Number
  , m32 :: Number
  }

It doesn't cause any problems currently, because the arguments are just passed in order to ctx.transform and ctx.setTransform. But, the names of the last two fields are wrong, which can lead to confusion.

In setTransform and transform (MDN docs links), they are primarily referred to as a, b, c, d, e, f, but also as m11, m12, m21, m22, dx, dy.

Also, ctx.getTransform returns a DOMMatrix, whose docs page mentions that e and f are equivalent to m41 and m42 respectively, and that m31 and m32 mean something completely different, relating to 3D transformations.

I remember talking briefly about this in Slack with Phil a while ago, but forgot to open an issue/PR for it.

I think the best solution would be to change Transform to look like this:

type Transform =
  { a :: Number
  , b :: Number
  , c :: Number
  , d :: Number
  , e :: Number
  , f :: Number
  }

Would this be reasonable to have as a breaking change for 0.14? I can make a PR for it if wanted.

[JordanMartinez]

I'm not familiar enough with this domain to respond.

[artemisSystem]

Do you know who would be? It would be nice to get this change in for 0.15, since it looks like you're suggesting/wanting to make some other breaking changes as well

[JordanMartinez]

I read through the links you posted and looked through the FFI. I also looked through #61. I agree that it makes sense to make your suggested change. Could you submit a PR?

[artemisSystem]

Thanks! Yes, i'll try to remember to make a PR later today or tomorrow