float2 UnpackUV(float uv)
{
    float2 output;
    output.x = floor(uv / 4096);
    output.y = uv - 4096 * output.x;

    return output * 0.001953125;
}

fixed4 GetColor(half d, fixed4 faceColor, fixed4 outlineColor, half outline, half softness)
{
    half faceAlpha = 1 - saturate((d - outline * 0.5 + softness * 0.5) / (1.0 + softness));
    half outlineAlpha = saturate((d + outline * 0.5)) * sqrt(min(1.0, outline));

    faceColor.rgb *= faceColor.a;
    outlineColor.rgb *= outlineColor.a;

    faceColor = lerp(faceColor, outlineColor, outlineAlpha);

    faceColor *= faceAlpha;

    return faceColor;
}

float3 GetSurfaceNormal(float4 h, float bias)
{
    bool raisedBevel = step(1, fmod(_ShaderFlags, 2));

    h += bias + _BevelOffset;

    float bevelWidth = max(.01, _OutlineWidth + _BevelWidth);

    // Track outline
    h -= .5;
    h /= bevelWidth;
    h = saturate(h + .5);

    if (raisedBevel) h = 1 - abs(h * 2.0 - 1.0);
    h = lerp(h, sin(h * 3.141592 / 2.0), _BevelRoundness);
    h = min(h, 1.0 - _BevelClamp);
    h *= _Bevel * bevelWidth * _GradientScale * -2.0;

    float3 va = normalize(float3(1.0, 0.0, h.y - h.x));
    float3 vb = normalize(float3(0.0, -1.0, h.w - h.z));

    return cross(va, vb);
}

float3 GetSurfaceNormal(float2 uv, float bias, float3 delta)
{
    // Read "height field"
    float4 h = {
        tex2D(_MainTex, uv - delta.xz).a,
        tex2D(_MainTex, uv + delta.xz).a,
        tex2D(_MainTex, uv - delta.zy).a,
        tex2D(_MainTex, uv + delta.zy).a
    };

    return GetSurfaceNormal(h, bias);
}

float3 GetSpecular(float3 n, float3 l)
{
    float spec = pow(max(0.0, dot(n, l)), _Reflectivity);
    return _SpecularColor.rgb * spec * _SpecularPower;
}

float4 GetGlowColor(float d, float scale)
{
    float glow = d - (_GlowOffset * _ScaleRatioB) * 0.5 * scale;
    float t = lerp(_GlowInner, (_GlowOuter * _ScaleRatioB), step(0.0, glow)) * 0.5 * scale;
    glow = saturate(abs(glow / (1.0 + t)));
    glow = 1.0 - pow(glow, _GlowPower);
    glow *= sqrt(min(1.0, t)); // Fade off glow thinner than 1 screen pixel
    return float4(_GlowColor.rgb, saturate(_GlowColor.a * glow * 2));
}

float4 BlendARGB(float4 overlying, float4 underlying)
{
    overlying.rgb *= overlying.a;
    underlying.rgb *= underlying.a;
    float3 blended = overlying.rgb + ((1 - overlying.a) * underlying.rgb);
    float alpha = underlying.a + (1 - underlying.a) * overlying.a;
    return float4(blended, alpha);
}
