Scale transformation corrections

nikochiko commented 10 months ago

I realised there are a couple of things wrong with the way we scale:

we scale linear dimensions by the sqrt of the scaling factor. i had suggested this, but it might be more intuitive to scale linearly by that factor. that is also what SVG does, and i feel we should maintain compatibility with SVG as much as possible for supporting multiple backends
we scale while keeping the center point same. this will break when we are scaling groups of shapes (one example was discussed by taking the line as an example here -- https://github.com/Sudha247/ocaml-joy/issues/49#issuecomment-1765940845). (e.g. three non-intersecting shapes will start intersecting when we scale them all as a complex shape).

e.g. we should be getting the scaled shapes like in the bottom canvas

The new calculations should handle the shapes like:

[x] #61
[x] #62
[ ] polygons -> multiply x and y coordinates of all points by the scaling factor (new shape type, to be added) -- #59

nikochiko commented 10 months ago

This can be broken down into a couple of issues

FayCarsons commented 10 months ago

I can take this one on!

nikochiko commented 10 months ago

@FayCarsons I've broken this down to three separate issues. Would you like to take up https://github.com/Sudha247/ocaml-joy/issues/59 ?

FayCarsons commented 10 months ago

Sure, but I'd also be happy to take on all of them if that'd be helpful!

Sudha247 / ocaml-joy