void ShadowCasterVP(
    float4 iPosition : POSITION,
        
    out float4 oPosition : POSITION,
    out float3 oViewPos : TEXCOORD0,
       
    uniform float4x4 cWorldViewProj,
    uniform float4x4 cWorldView
    )
{
    oPosition = mul(cWorldViewProj, iPosition);
    oViewPos = mul(cWorldView, iPosition).xyz;
}

void ShadowCasterFP(
    float4 oPosition : POSITION,
    float3 iViewPos : TEXCOORD0,
		
    out float4 oColor : COLOR0,
        
    uniform float cFarDistance
    )
{
	float depth = length(iViewPos) / cFarDistance;
    oColor.rgba = float4(depth, depth, depth, 1);
}