Add update_skew to RemoteTransform2D

[daniel-szarkowicz]

Fixes #103368 by adding an update_skew property to the RemoteTransform2D.

[KoBeWi]

Seems to work correctly.

Looks like it will supersede #103377
CC @Rindbee

[Rindbee]

set_rotation_scale_and_skew() is quite universal, but in some cases, it may not be the fastest. In cases where only scale or skew needs to be set, it may be faster to call the corresponding setter. Benchmarking may be required.

[KoBeWi]

I just noticed that code for updating local and global transform looks the same. It could be moved to a method.

[Rindbee]

godot/doc/classes/Node2D.xml

Line 128 in 1753893

[b]Note:[/b] Negative X scales in 2D are not decomposable from the transformation matrix. Due to the way scale is represented with transformation matrices in Godot, negative scales on the X axis will be changed to negative scales on the Y axis and a rotation of 180 degrees when decomposed.

The effect of negative x scale on rotation should be eliminated when update remote scale is disabled.

[daniel-szarkowicz]

godot/doc/classes/Node2D.xml

Line 128 in 1753893

[b]Note:[/b] Negative X scales in 2D are not decomposable from the transformation matrix. Due to the way scale is represented with transformation matrices in Godot, negative scales on the X axis will be changed to negative scales on the Y axis and a rotation of 180 degrees when decomposed.

The effect of negative x scale on rotation should be eliminated when update remote scale is disabled.

I don't think effect on the rotation can be negated reliably, so I added these notes to update_scale too. The negative y scale getting updated when update_scale is disabled was caused by a bug in Transform2D's set_scale, which now should be fixed.

[Rindbee]

I tested the elapsed time of these methods: set_scale() << set_rotation_scale_and_skew() < set_skew()

That is, if you don't just call set_scale(), it is better to call set_rotation_scale_and_skew() directly. You can single out the case where only set_scale() is called.