A shadow map shader to use in a XNA/MonoGame application.

ShadowMap.fx

float4x4 World;
float4x4 View;
float4x4 Projection;

struct VertexShaderInput
{
    float4 Position : POSITION0;
};

struct VertexShaderOutput
{
    float4 Position : POSITION0;
	float2 depth:TEXCOORD0;
};

VertexShaderOutput VertexShaderFunction(VertexShaderInput input)
{
    VertexShaderOutput output;
    float4 worldPosition = mul(input.Position, World);
    float4 viewPosition = mul(worldPosition, View);
    output.Position = mul(viewPosition, Projection);
	output.depth = output.Position.zw;
	
    return output;
}

float4 PixelShaderFunction(VertexShaderOutput input) : COLOR0
{
    return input.depth.x /input.depth.y;
}

technique Technique1
{
    pass Pass1
    {
#if SM4
		VertexShader = compile vs_4_0_level_9_3 VertexShaderFunction();
		PixelShader = compile ps_4_0_level_9_3 PixelShaderFunction();
#else
        VertexShader = compile vs_3_0 VertexShaderFunction();
		PixelShader = compile ps_3_0 PixelShaderFunction();
#endif
    }
}