svg2gcode v0.2.0: coordinate system overhaul

This commit completely changes how the coodinate system works based on a
read-through of the W3C SVG docs. It should be _correct_ now.

Circular interpolation is still EXPERIMENTAL! There are known bugs, even
in the test output :(

Miscellaneous brain dump of changes:

- Support polygon
- Better docs
- Explained why transforms are in the opposite order of what you
  would expect
- Support preserveAspectRatio
- Proper viewBox support
- Fix SVG -> g-code coordinate system mapping
- DPI conversion: only apply after svg is processed via a wrapper turtle
- Proper handling for percentage units
- Clean up converter/mod.rs, split it up
- Nested viewport support (untested)

Author: sameer

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "svg2gcode"
-version = "0.1.6"
+version = "0.2.0"
 authors = ["Sameer Puri <crates@purisa.me>"]
 edition = "2021"
 description = "Convert paths in SVG files to GCode for a pen plotter, laser engraver, or other machine."

lib/Cargo.toml

@@ -284,6 +284,7 @@ mod tests {
     use crate::arc::{ArcOrLineSegment, FlattenWithArcs};
 
     #[test]
+    #[ignore = "Creates an image file, will revise later"]
     fn flatten_returns_expected_arcs() {
         const PATH: &'static str = "M  8.0549,11.9023
         c

lib/src/arc.rs

@@ -1,3 +1,6 @@
+//! Makes it possible to serialize an array of two optional [`svgtypes::Length`]s,
+//! used for [super::ConversionOptions::dimensions]
+
 use serde::{
     de::{SeqAccess, Visitor},
     ser::SerializeSeq,