import FluidGridData;

struct Parameter
{
    float iso;
    FluidGridData<float> density;
    RWStructuredBuffer<float3> vertices;
    RWStructuredBuffer<uint> indices;
    RWStructuredBuffer<uint> surfaceCount;
    RWStructuredBuffer<uint> vertexCount;
};
ParameterBlock<Parameter> params;

float getDensity(uint x, uint y, uint z)
{
    return params.density[x + gridSize.x * y + gridSize.x * gridSize.y * z];
}

[shader("compute")]
[numthreads(32, 8, 1)]
void main(uint3 dispatchThreadID : SV_DispatchThreadID)
{
    uint x = dispatchThreadID.x+1;
    uint y = dispatchThreadID.y+1;
    uint z = dispatchThreadID.z+1;
    FluidGridData<float> density = params.density;
    if(x >= gridSize.x-3 || y >= gridSize.y-3 || z >= gridSize.z-3) return;

    float phi[8] = {
        getDensity(x, y, z),
        getDensity(x + 1, y, z),
        getDensity(x, y + 1, z),
        getDensity(x + 1, y + 1, z),
        getDensity(x, y, z + 1),
        getDensity(x + 1, y, z + 1),
        getDensity(x, y + 1, z + 1),
        getDensity(x + 1, y + 1, z + 1)
    };

    uint cubeIndex = 0;
    for (uint i = 0; i < 8; ++i) {
        if (phi[i] < params.iso) {
            cubeIndex |= (1 << i);
        }
    }
    if(cubeIndex == 0 || cubeIndex == 255) return;
}