#ifndef WMARK_H
#define WMARK_H

#include "common.hlsli"

#define NORMAL_SHIFT 0.007f
#define MIN_SHIFT 0.003f
#define MAX_SHIFT 0.011f
#define RANGE 100.f

float4 wmark_shift(float3 pos, float3 norm)
{
    float3 P = pos;
    float3 N = norm;
    float3 sd = eye_position - P;
    float d = length(sd);
    float w = min(d / RANGE, 1.f);
    float s = lerp(MIN_SHIFT, MAX_SHIFT, d);
    P += N.xyz * NORMAL_SHIFT;
    P -= normalize(eye_direction + normalize(P - eye_position)) * s;
    return float4(P, 1.f);
}

#endif
