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What vertex shader code should be used for a pixel shader used for simple 2D SpriteBatch drawing in XNA?
Invalid effect file. Unable to find vertex shader in pass "P0"

void SpriteVertexShader(inout float4 color    : COLOR0,
                        inout float2 texCoord : TEXCOORD0,
                        inout float4 position : SV_Position)
{
    position = mul(position, MatrixTransform);
}

Matrix projection = Matrix.CreateOrthographicOffCenter(0, viewport.Width, viewport.Height, 0, 0, 1);
Matrix halfPixelOffset = Matrix.CreateTranslation(-0.5f, -0.5f, 0);
Matrix transformation = halfPixelOffset * projection;

float2 Viewport; //Set to viewport size from application code

void SpriteVertexShader(inout float4 color    : COLOR0,
                       inout float2 texCoord : TEXCOORD0,
                       inout float4 position : POSITION0)
{
   // Half pixel offset for correct texel centering.
   position.xy -= 0.5;
   // Viewport adjustment.
   position.xy = position.xy / Viewport;
   position.xy *= float2(2, -2);
   position.xy -= float2(1, -1);
}