Feature Request Compute Shader Set Bools?

https://docs.unity3d.com/ScriptReference/ComputeShader.html
Compute shader api have setting array options for floats and ints. But not for booleans. In hlsl i can write bool array. I may use int array instead of bool array but why there is no option for setting bool array in this api?

 

While you can use bools in local variables in shaders, GPUs don't actually support storing bools in memory buffers, which is where the values you pass from the CPU are stored under the hood. At most you could pack your bools into the bits of an int and unpack those in the shader, but that's only worthy if you have hundreds of thousands of them.

 

To elaborate on what Neto is saying, the reason they don't properly support them is because most modern GPUs deal in 32bit floats, with a pipeline sized for 128bit packs of data (float4). There are some older mobile platforms that use lower precision value types, but it's still nowhere near as low as a single bit or byte (except in the niche use case of things like Tensor cores using Int16/8)).

So simply use an integer array and set 0 or 1. Or if you're looking for more space saving, use

.SetData()

with a ComputeBuffer that has an array of bytes stored in it. And in the most extreme, you can use Neto's suggestion of bit packing to store multiple values per element.