#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

uniform float3 eye_direction;

float4 wmark_shift(float3 P, float3 N)
{
    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 - sd * rcp(d)) * s;

    return float4(P, 1.f);
}
#endif