struct VertexOutput
{
    float4 position : SV_Position;
};

VertexOutput MainVS(uint vertexId : SV_VertexID)
{
    VertexOutput output = (VertexOutput)0;
    float2 quadPosition = float2(vertexId & 1, (vertexId >> 1) & 1) * 4.0 - 1.0;
    output.position = float4(quadPosition, 1.0, 1.0);
    return output;
}