PoolColorArray.set doesn't work

[henriiquecampos]

Godot version: 3.0.3

OS/device including version: Linux x64 (SolusOS 3.9999 Gnome 3.28.2)

Issue description:

I'm trying to use Polygon2D.vertex_color.set(0, color) and this approach doesn't do nothing, while vertex_colors[0] = color works, the below doesn't:

func _ready():
	var color = Color(1, 1, 1, 1)
	print(color)
	vertex_colors.set(0, color)
	print(vertex_colors[0])

the print returns:

1,1,1,1
1,0.701961,0.501961,1

While Polygon2D.vertex_color by creating another PoolColorArray:

var white = Color(1, 1, 1, 1)
	var colors = [white, white, white, white]
	print(colors[0])
	vertex_colors = colors
	print(vertex_colors[0])

the print returns:

1,1,1,1
1,1,1,1

Both are reflected in the actual game (first one doesn't modify the Polygon2D vertex colors, second approach does)

Also, during some tests I realized that unfortunately we have a not true statement on latest post about the Animation System.

I tried to Tween.interpolate_property and Tween.interpolate_method both trying to interpolate the Polygon2D.vertex_color and I got this error:

0:00:00:0209 - Invalid param type, except(int/real/vector2/vector/matrix/matrix32/quat/aabb/transform/color)
----------
Type:Error
Description: 
Time: 0:00:00:0209
C Error: Invalid param type, except(int/real/vector2/vector/matrix/matrix32/quat/aabb/transform/color)
C Source: scene/animation/tween.cpp:991
C Function: _calc_delta_val

So it seems like:

any property from any object can be animated or tweened

Is not true, unfortunately :(

Steps to reproduce:

1. Create a Polygon2D
2. On its vertex_colors property create the desired array
3. Try to PoolColorArray.set(index, color)

---

1.Create 2 PoolColorArray
2. Try to Tween.interpolate_property using them as initial_value and final_value

Minimal reproduction project:

Polygon2D.zip

[insomniacUNDERSCORElemon]

This also happens using the animationplayer as well, which I'm assuming is the same issue. The vertex colors change, but interpolation is not properly used (however interpolation works for a polygon's vertex and UV coordinates).

[Chaosus]

Its because Polygon2D.vertex_color is a property and what you setted up is a copy of this variable returned by getter of this property. I agree that should be at least a warning here cc @vnen

[vnen]

Don't know if I can do anything about it, it's just how PoolVector works. IMO this is more of a documentation problem.

[insomniacUNDERSCORElemon]

@Chaosus @vnen As I mentioned it happens with the editor as well... so will that just result in an triangle warning (like the ones that pop up in the scene tree when you need to configure things a certain way) explaining that vertex colors cannot be interpolated?

Or is there/could there be a 'proper' way to do this that the GUI method could use?

EDIT: Sorry, I'm not sure if the issue is directly related, but I now see issue #14873 is the more relevant issue (and it's older) to vertex color interpolation via the GUI.

[madmiraal]

Related to #17310 and #39887. The setter is not called because, although the contents of the Array are changed, the Array pointed to does not change.