Methods Returning Arrays (in .cginc)

I think I found a way to massively optimise some of my procedurally generated meshes, but to do so I need to access what is effectively a nested array in my shaders.

So first approach, flatten the thing but I will need more than 1024 values which is likely Unitys limit for array sizes (Reference: https://forum.unity.com/threads/material-setvectorarray-array-size-limit.512068/)

Instead what I am trying to do is something like this in a CG Includes file:

Code (CSharp):

1. float4 BendAxis1 [14];
2. float4 BendAxis2 [14];
3.  
4.         float4[] GetAxis(int index)
5.         {
6.           if(index == 0)
7.             return BendAxis1;
8.          else
9.            return BendAxis2;
10. //then many more checks for other axis
11.         }
12.  

Problem is, the shader wont compile and doesn't like: float4[] GetAxis(int index) because of "Unexpected token '['"

Any idea if its possible to return an array in shaders and if so what the syntax would be?

I could probably get around this with a baked texture lookup but would be a far messier solution so would rather avoid that!

 

Example:

Code (CSharp):

1.             // fill array with random data - 2..xxxx is shorthand for "float4(2,2,2,2)" etc.
2.             static const float4 BendAxis1 [14] = {float4(1,0,0,1), { 0.2, 0.3, 0.4, 0.5 }, 2..xxxx,3..xxxx,4..xxxx,5..xxxx,6..xxxx,0..xxxx,1..xxxx,2..xxxx,3..xxxx,4..xxxx,5..xxxx,6..xxxx};
3.             static const float4 BendAxis2 [14] = {float4(0,0,1,1), { 0.2, 1.0, 0.4, 0.1 }, 4..xxxx,6..xxxx,8..xxxx,0..xxxx,2..xxxx,4..xxxx,6..xxxx,8..xxxx,0..xxxx,2..xxxx,4..xxxx,6..xxxx};
4.            
5.             void GetAxis(int index, float4 a[14], float4 b[14], out float4 c[14])
6.             {
7.                 if(index == 0)
8.                     c = a;
9.                 else
10.                     c = b;
11.             }
12.            
13.             fixed4 frag (v2f i) : SV_Target
14.             {
15.                 float4 BendAxis3 [14];
16.                 GetAxis(0, BendAxis1, BendAxis2, BendAxis3);
17.                 return BendAxis3[0];  // return red
18.                
19.                 //GetAxis(1, BendAxis1, BendAxis2, BendAxis3);
20.                 //return BendAxis3[0];  // return blue              
21.             }

 

Huh didn't think to try 'out'. Thanks this works