fix(RotateTool.js): evaluation of initialRotation

[wang0122xl]

fix: RotateTool rotate too quick when viewport.initialRotation is 0

• Please check if the PR fulfills these requirements

• The commit message follows our guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)
  Bug fix

• What is the current behavior? (You can also link to an open issue here)
  RotateTool rotate too quick when viewport.initialRotation is 0

• What is the new behavior (if this is a feature change)?
  rotate normally

• Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)
  No

• Other information:

[codecov]

Codecov Report

Merging #1461 (75ea421) into master (95c3b7c) will not change coverage.
The diff coverage is 0.00%.

@@           Coverage Diff           @@
##           master    #1461   +/-   ##
=======================================
  Coverage   20.16%   20.16%           
=======================================
  Files         287      287           
  Lines       10102    10102           
  Branches     2060     2060           
=======================================
  Hits         2037     2037           
  Misses       6852     6852           
  Partials     1213     1213           

Impacted Files	Coverage Δ
src/tools/RotateTool.js	16.66% <0.00%> (ø)

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[LaurentTrk]

Hi !
I ran into the same problem.
The recent change introduced in the 5.2.0 release has been made on purpose : Fix RotateTool on mobile devices (#1385) (cdf23b5).

Checking for undefined should preserved both attended behaviours :

  const initialRotation = viewport.initialRotation !== undefined
    ? viewport.initialRotation
    : viewport.rotation;

Hope it helps 🙏

For those needing the fix urgently, you can use a custom strategy with the RotateTool.

[wang0122xl]

@LaurentTrk Thx, I just made a new commit including the condition of undefined.