#ifndef _GRADIENTDISSOLVE
#define _GRADIENTDISSOLVE
 
half4 MergeColors(half4 background, half4 sample)
{
    half4 _out = lerp(background, sample, sample.a);
    _out.a = 1;
    return _out;
}

void GradientedDissolve_float(
    UnityTexture2D NoiseTexture, UnityTexture2D BaseTexture, UnityTexture2D GUITexture,
    UnitySamplerState NoiseSS,
    half2 UV, half2 UV2,
    half NoisePow, half Width, half Th,
    out half4 _out
    )
{
    _out = SAMPLE_TEXTURE2D(BaseTexture, NoiseSS, UV);
  
    half noise = SAMPLE_TEXTURE2D(NoiseTexture,  NoiseSS, UV).r;
    noise = pow(noise, NoisePow);
    noise = noise * (1-UV.x);
    noise += Th;
    bool inRange = UV2.x >= 0.0 && UV2.x <= 1.0 && UV2.y >= 0.0 && UV2.y <= 1.0;
    
    if (inRange)
    {
        half4 guiSample = SAMPLE_TEXTURE2D_LOD(GUITexture, NoiseSS, UV2, 0);
        half4 guiSampleLow = SAMPLE_TEXTURE2D_LOD(GUITexture, NoiseSS, UV2, 3);
        if (noise > 1.0)
        {
            noise = 1.0;
            //_out.xyz = _out.xyz * (guiSample+OffsetColor);
            _out.xyz = MergeColors(_out, guiSample).xyz;
            //_out.xyz = guiSample.rrr;
        }
        else if ((noise +  Width ) > 1.0)
        {
            noise = (noise + Width - 1.0)/Width;
            half4 gui = lerp(guiSampleLow, guiSampleLow, noise);
            //float3 full = _out.xyz * gui;
            half4 full = MergeColors(_out, guiSample);
            _out.xyz = lerp(_out, full, noise).xyz;
        }
        else {
            noise = 0.0;
        }
    }
    
}

#endif