Optimize Gradient2 when 'ModifyMesh' called

[bluefallsky]

Unity UI Extensions - Pull Request

Overview

Gradient2 optimization

Changes

Optimize Garbage when 'ModifyMesh' called, when target graphic's tint color changed or Gradient2 offset, zoom field changed.

• Fixes: Android: Gradient2 performance impact #391
  It may seems related to Android: Gradient2 performance impact #391

Breaking Changes

• Change List and array constructor to pool rent call
• Change Default Sort method(DefaultArrayHelper) that generate garbage
• Cache field 'colorKeys' and 'alphaKeys' that generate garbage when every referece
• Some unity version support

Related Submodule Changes

None

Testing status

• No tests have been added.

Manual testing status

https://github.com/bluefallsky/com.unity.uiextensions/tree/enhance/gradient2-optimize
sample scene path - WorkSpace/Gradient2/Gradient2Test.unity
For comparative testing, testing was conducted with Gradient2Optimize.cs

[SimonDarksideJ]

Only just seeing this @bluefallsky, sorry for the delay. And WOW Unity, I see some clever flipping with the Unity version checks there.

Will review ASAP. Retargetted to the development branch however.