// Each #kernel tells which function to compile; you can have many kernels
#pragma kernel CSMain

// Create a StructuredBuffer/ComputeBuffer with read only flag.
StructuredBuffer<int> inputData;
// Create a StructuredBuffer/ComputeBuffer with read & write flag.
RWStructuredBuffer<int> outputData;

// We allocate 20 threads one for each number given to the shader.
// CSMain is the entry point we use we have to define the entry points as kernel.
[numthreads(20,1,1)]
void CSMain (uint3 id : SV_DispatchThreadID)
{
    // We use the thead id as index for the data.
    outputData[id.x] = 2 * inputData[id.x];
}