Additional swizzle for arbitrary data?

[mbechard]

Stemming from an internal discussion we are currently having at my company. The data manipulated in shaders is often neither position/direction (xyzw) nor Color (rgba). So using those swizzles to access that data imparts incorrect information to the reader. One example is a vec2 holding something like (index, weight), and the code is accessing it via .xy.
Is there any interest/thoughts about adding an additional swizzle that is more appropriate for arbitrary data?

[csyonghe]

It appears to me that you may want to use a dedicated struct type to encode those things with different meaning? May I understand more detail on what's preventing you from doing:

struct WeightObject
{
    int index;
    float weight;
}

[mbechard]

Yeah, that is a workflow that would work for a lot of cases. If the data is already in a float4 though (such as coming from a texture), you can't do that.
Also the struct workflow doesn't allow for the use of swizzles.
It's not a high priority ask at all, just curious about thoughts about a generic swizzle beyond the two that are available.

[csyonghe]

You can use reinterpret to cast a float4 to some other type:

struct MyObject { int index; float v; };

void test()
{
     let object = reinterpret<MyObject>(texture.Load(uint2(0,0)).xy);
}

[csyonghe]

We don't have swizzle for struct types, however, Tuple types does have swizzle support.

Tuple<int, float, float> t;
Tuple<float,float> v = t._1_2;

[mbechard]

Ah great, yeah that answers it then. Seems like it's covered enough by those two cases. Thanks!