Texture2DArray broken?

I need to use a texture array in my GLSL shader, targeting webGL 2. It works perfectly in the editor, but not when running on the web.

Code (CSharp):

1. Debug.Log("supports2DArrayTextures: " + SystemInfo.supports2DArrayTextures);
2.  

reports true. Texture arrays are supposed to work according to the ES3 specs. Unity docs says:

Platform Support
Texture arrays need to be supported by the underlying graphics API and the GPU. They are available on:

• Direct3D 11/12 (Windows, Xbox One)
• OpenGL Core (Mac OS X, Linux)
• Metal (iOS, Mac OS X)
• OpenGL ES 3.0 (Android, WebGL 2.0)
• PlayStation 4

What is happening here, is this a bug in Unity, or am I doing something wrong?

This is the shader:

Code (CSharp):

1. Shader "testshader" {
2.     Properties{ _MainTex("Base (RGB)", 2D) = "white" {} }
3.         SubShader{
4.         Tags { "Queue" = "Geometry" }
5.         Pass {
6.         GLSLPROGRAM
7.         #ifdef VERTEX
8.  
9.         varying vec2 TextureCoordinate;
10.         void main()
11.         {
12.             gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
13.             TextureCoordinate = gl_MultiTexCoord0.xy;
14.         }
15.         #endif
16.  
17. #ifdef FRAGMENT
18.  
19. precision mediump sampler2DArray;
20.  
21. uniform sampler2D _MainTex;
22. uniform sampler2DArray textureArray;
23. varying vec2 TextureCoordinate;
24.  
25.  
26. void main(void)
27. {
28.     vec3 uvz = vec3(TextureCoordinate, 0);
29.     vec4 c = texture(textureArray, uvz);
30.     gl_FragColor = c;
31. }
32.  
33.  
34. #endif
35. ENDGLSL} }}
36.  

I always get white from the sampler, no matter what is in the texture arrays. The textures are in the correct format (RGBA32) and size (1024x1024).

This is the script:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class Test : MonoBehaviour
6. {
7.     public Material testMaterial;
8.     public Texture2DArray texturesArray;
9.     public List<Texture2D> textures;
10.  
11.     private Texture2DArray createTexture2DArray(List<Texture2D> textures, int size)
12.     {
13.         Texture2DArray texture2DArray = new Texture2DArray(size, size, textures.Count, TextureFormat.RGBA32, false);
14.         texture2DArray.filterMode = FilterMode.Bilinear;
15.         texture2DArray.wrapMode = TextureWrapMode.Repeat;
16.  
17.         for (int i = 0; i < textures.Count; i++)
18.         {
19.             //Copy to the array texture
20.             Graphics.CopyTexture(textures[i], 0, 0, texture2DArray, i, 0);
21.         }
22.         return texture2DArray;
23.     }
24.  
25.  
26.  
27.     void Start()
28.     {
29.         texturesArray = createTexture2DArray(this.textures, 1024);
30.         testMaterial.SetTexture("textureArray", texturesArray);
31.         Debug.Log("supports2DArrayTextures: " + SystemInfo.supports2DArrayTextures);
32.     }
33.  
34.     void Update()
35.     {
36.  
37.     }
38. }

I have also tested with an HLSL equivalent, using this:

https://gist.github.com/Spaxe/57de76c993a4dc8bb37275acbe597ef2

Same story there, works in the editor but not in the browser.

It looks to me like

Code (CSharp):

1. /Graphics.CopyTexture(textures[i], 0, 0, texture2DArray, i, 0);

Is not working in WebGL, as I get the same result in the editor if I omit this.

 

Okay, answering my own question here, as usual...

I found a workaround:

Code (CSharp):

1.  
2. if (SystemInfo.copyTextureSupport==UnityEngine.Rendering.CopyTextureSupport.None)
3.    texture2DArray.SetPixelData(t.GetRawTextureData(), 0, i);          
4. else
5.    Graphics.CopyTexture(t, 0, 0, texture2DArray, i, 0);
6. ...
7. texture2DArray.Apply();
8.  
9.  

The texture formats must match exactly,