Generate mipmaps for HiZ

compute->SetPipelineState(mMipmapPS);
compute->SetRootSignature(mMipmapRS);
compute->SetDescriptorHeap(Engine::DescriptorHeap::CBV_SRV_UAV, heap);

compute->TransitionResource(mColorBuffer, RESOURCE_STATE_UNORDERED_ACCESS, true);

int todo = mNumMipmaps - 1;
int base = 0;
int dimension[2] = { (int)mWidth, (int)mHeight };

while (todo != 0)
{
    int mipLevels = 3;

    int npotflag = 0;
    if (((dimension[0] % 2) == 1) && ((dimension[1] % 2) == 1))
    {
        npotflag = 3;
    }
    else if ((dimension[1] % 2) == 1)
    {
        npotflag = 2;
    }
    else if ((dimension[0] % 2) == 1)
    {
        npotflag = 1;
    }

    if (todo == 1)
    {
        mipLevels = 1;
    }
    else if (todo == 2)
    {
        mipLevels = 2;
    }

    int dispatch[2] = { 0, 0 };
    dispatch[0] = dimension[0] / 8;
    if ((dimension[0] % 8) > 0)
    {
        dispatch[0]++;
    }

    dispatch[1] = dimension[1] / 8;
    if ((dimension[1] % 8) > 0)
    {
        dispatch[1]++;
    }

    if (dispatch[0] == 0 && dispatch[1] > 0)
    {
        dispatch[0] = 1;
    }
    else if (dispatch[0] > 0 && dispatch[1] == 0)
    {
        dispatch[1] = 1;
    }
    else if (dispatch[0] == 0 && dispatch[1] == 0)
    {
        break;
    }

    compute->SetConstants(0, Engine::DWParam(base), Engine::DWParam(npotflag), Engine::DWParam(1.0f / (float)dimension[0]), Engine::DWParam(1.0f / (float)dimension[1]));
    compute->SetConstants(1, Engine::DWParam(mipLevels), Engine::DWParam(mipLevels), Engine::DWParam(mipLevels), Engine::DWParam(mipLevels));
    compute->SetDescriptorTable(2, mColorBuffer->GetSRV());
    compute->SetDescriptorTable(3, mColorBuffer->GetUAV(base + 1));
    if (mipLevels >= 2) { compute->SetDescriptorTable(4, mColorBuffer->GetUAV(base + 2)); }
    if (mipLevels >= 3) { compute->SetDescriptorTable(5, mColorBuffer->GetUAV(base + 3)); }
    compute->Dispatch(dispatch[0], dispatch[1], 1);
    compute->TransitionResource(mColorBuffer, RESOURCE_STATE_UNORDERED_ACCESS, true);

    todo -= mipLevels;
    base += mipLevels;
    dimension[0] /= 2 << (mipLevels - 1);
    dimension[1] /= 2 << (mipLevels - 1);
}