feat: call evalShapes only twice to generate a computation graph

[wodeni]

Description

Related issue/PR: #971

Currently, the system calls shapeAutodiffToNumber(evalShapes(state)) (1) after taking a step in the optimizer, (2) after resampling, and (3) when generating the initial shape. Internally, evalShapes constructs a computational graph with no inputs (specifically, the varying values are plugged in as constants) and just extract the shape properties at the end.

Because the computation graph doesn't change during optimization, there's actually no point re-constructing the graph when evaluating shapes. Instead, it would be much more efficient to compile the computation graph only once, and call the compiled function with new varying values to get the new shapes.

As a next step of #971, in this PR, we call the evaluator only once during compilation, and use a computation graph for evaluation at runtime.

Implementation strategy and design decisions

• We kept most of Evaluator intact, and use it to generate a comp graph in compileCompGraph.
• compileCompGraph is called (1) before collectLabels (to refactor later because it really doesn't need fully evaluated shapes), (2) in genOptProblem for actually generating computeShapes (the compiled autodiff function), and (3) after resampling.
• Because we don't have derivative nodes as secondary outputs (see refactor: Style compiler cleanup #971), derivative and derivativePreconditioned will not be updated during evaluation. Therefore, we decided to stop supporting them.

Examples with steps to reproduce them

See https://github.com/penrose/penrose/suites/6548051374/artifacts/244548940

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

Questions that require more discussion or to be addressed in future development:

[codecov]

Codecov Report

Merging #976 (cd0f94b) into main (012aec1) will increase coverage by 0.57%.
The diff coverage is 84.47%.

❗ Current head cd0f94b differs from pull request most recent head 4e02dda. Consider uploading reports for the commit 4e02dda to get more accurate results

@@            Coverage Diff             @@
##             main     #976      +/-   ##
==========================================
+ Coverage   63.13%   63.71%   +0.57%     
==========================================
  Files          62       62              
  Lines        7813     7789      -24     
  Branches     1814     1782      -32     
==========================================
+ Hits         4933     4963      +30     
+ Misses       2762     2714      -48     
+ Partials      118      112       -6     

Impacted Files	Coverage Δ
packages/core/src/contrib/Functions.ts	14.43% <ø> (+0.82%)	⬆️
packages/core/src/shapes/Samplers.ts	91.17% <ø> (-0.93%)	⬇️
packages/core/src/engine/Evaluator.ts	31.33% <65.27%> (-2.18%)	⬇️
packages/core/src/compiler/Style.ts	78.20% <100.00%> (-0.09%)	⬇️
packages/core/src/contrib/Constraints.ts	82.11% <100.00%> (+0.60%)	⬆️
packages/core/src/contrib/ConstraintsUtils.ts	82.25% <100.00%> (+1.06%)	⬆️
packages/core/src/contrib/Minkowski.ts	99.20% <100.00%> (+0.36%)	⬆️
...e/src/contrib/__testfixtures__/TestShapes.input.ts	100.00% <100.00%> (ø)
packages/core/src/engine/EngineUtils.ts	65.35% <100.00%> (+2.59%)	⬆️
packages/core/src/engine/Optimizer.ts	81.03% <100.00%> (+0.05%)	⬆️
... and 4 more

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[samestep]

Looks good 👍