cbuffer VS_CONSTANTS
{
    float4x4 dummy;
    float2 viewSize;

};

struct VS_OUTPUT
{
    float4 position   : SV_Position;    // vertex position
    float2 ftcoord    : TEXCOORD0;      // float 2 tex coord
    float2 fpos       : TEXCOORD1;      // float 2 position
};

VS_OUTPUT D3D11VertexShader_Main(float2 pt : POSITION, float2 tex : TEXCOORD0)
{
    VS_OUTPUT Output;
    Output.ftcoord = tex;
    Output.fpos = pt;
    Output.position = float4(2.0 * pt.x / viewSize.x - 1.0, 1.0 - 2.0 * pt.y / viewSize.y, 0, 1);

    return Output;
}