#pragma kernel ClearDispatchIndirect
#pragma only_renderers d3d11 ps4 xboxone vulkan metal switch

RWBuffer<uint> g_DispatchIndirectBuffer : register( u0 );   // Indirect arguments have to be in a _buffer_, not a structured buffer

#include "LightLoop.cs.hlsl"

[numthreads(64, 1, 1)]
void ClearDispatchIndirect(uint dispatchThreadId : SV_DispatchThreadID)
{
    // On iOS, we get a GPU hang/reset based upon the execution of the ClearDispatchIndirect kernel.
    // The buffer is created using the 'NUM_FEATURE_VARIANTS' constant but we're dispatching a threadgroup of 64 threads, so we are presumably going out of bounds (Metal GPU errors are not terribly descriptive, but this is a common cause).
    // In DirectX out-of-bounds reads are always zero and out-of-bounds writes are are a no op. 
    if (dispatchThreadId >= NUM_FEATURE_VARIANTS)
        return;

    g_DispatchIndirectBuffer[dispatchThreadId * 3 + 0] = 0; // ThreadGroupCountX
    g_DispatchIndirectBuffer[dispatchThreadId * 3 + 1] = 1; // ThreadGroupCountY
    g_DispatchIndirectBuffer[dispatchThreadId * 3 + 2] = 1; // ThreadGroupCountZ
}