feat: Add examples with nonconvex shapes

[jiriminarcik]

Description

Followup to #877.

Added new examples with non-convex shapes and fixed some issues with the convex partitioning algorithm by switching to library poly-partition (see comments below).

Examples with steps to reproduce them

• Triangle maze example:

Run npx roger watch maze.sub maze.sty maze.dsl in folder examples/minkowski-tests/maze.

• Yin-Yang example:

Run npx roger watch yin-yang.sub yin-yang.sty yin-yang.dsl in folder examples/minkowski-tests/yin-yang.

Checklist

• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new ESLint warnings
• I have reviewed any generated changes to the diagrams/ folder

Open questions

The optimiser struggles with the Yin-Yang example and often get stuck at an undesirable local minimum.

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Codecov Report

Merging #893 (f05a3fa) into main (009a1bc) will increase coverage by 0.73%.
The diff coverage is 100.00%.

❗ Current head f05a3fa differs from pull request most recent head ddea702. Consider uploading reports for the commit ddea702 to get more accurate results

@@            Coverage Diff             @@
##             main     #893      +/-   ##
==========================================
+ Coverage   67.43%   68.17%   +0.73%     
==========================================
  Files          62       62              
  Lines        8181     8115      -66     
  Branches     1771     1767       -4     
==========================================
+ Hits         5517     5532      +15     
+ Misses       2657     2576      -81     
  Partials        7        7              

Impacted Files	Coverage Δ
packages/core/src/engine/Autodiff.ts	81.41% <ø> (+6.74%)	⬆️
packages/core/src/types/ad.ts	100.00% <ø> (ø)
packages/core/src/contrib/Minkowski.ts	100.00% <100.00%> (+2.43%)	⬆️
packages/core/src/engine/AutodiffFunctions.ts	50.16% <100.00%> (+0.08%)	⬆️
packages/core/src/engine/Evaluator.ts	62.20% <0.00%> (+0.52%)	⬆️
packages/core/src/engine/EngineUtils.ts	68.64% <0.00%> (+0.95%)	⬆️
packages/core/src/renderer/AttrHelper.ts	83.73% <0.00%> (+9.03%)	⬆️
packages/core/src/renderer/Polygon.ts	100.00% <0.00%> (+75.00%)	⬆️

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[samestep]

Visualization of the TypeError: polygon decomposition unexpectedly created a new point for examples/minkowski-test/yin-yang/ (it is indeed creating a new point):

[samestep]

The poly-decomp.js library (linked from #877) links to this page describing an algorithm, which explains the circumstances under which it inserts these Steiner points: https://mpen.ca/406/bayazit

[samestep]

I opened x6ud/poly-partition-js#1 which would allow make convexPartitions work for polygons of arbitrary orientation:

diff --git a/packages/core/src/contrib/Minkowski.ts b/packages/core/src/contrib/Minkowski.ts
index d774e67f0..cd235e3a4 100644
--- a/packages/core/src/contrib/Minkowski.ts
+++ b/packages/core/src/contrib/Minkowski.ts
@@ -161,6 +161,9 @@ export const convexPartitions = (p: VarAD[][]): VarAD[][][] => {
   );
 
   const contour = [...pointMap.keys()];
+  if (isClockwise(contour)) {
+    contour.reverse();
+  }
   const convexPolygons = convexPartition(contour);
 
   return convexPolygons.map((poly) =>

[samestep]

Looks great, thanks @jiriminarcik! Do you want to add any of these to the registry?

[jiriminarcik]

Looks great, thanks @jiriminarcik! Do you want to add any of these to the registry?

I added the maze example.