void main(
    float2 aPosition,
    float2 aTexcoord,
    float4 aColor,
    uniform float4x4 wvp,
    out float4 vPosition : POSITION,
    out float4 vColor : COLOR,
    out float2 vTexcoord : TEXCOORD0
)
{
    vPosition = mul(float4(aPosition, 1.f, 0.5f), wvp);
    vTexcoord = aTexcoord;
    vColor = aColor;
}
