// motion blur reconstruction filter pass

uniform float4 _ZBufferParams ;
inline float Linear01Depth ( float z )
{
    return 1.0 / ( _ZBufferParams . x * z + _ZBufferParams . y ) ;
}
struct v2f
{
    float4 pos : POSITION ;
    float2 uv : TEXCOORD0 ;
}
;
sampler2D _MainTex ;
sampler2D _CameraDepthTexture ;
sampler2D _VelTex ;
sampler2D _NeighbourMaxTex ;
sampler2D _NoiseTex ;
float4 _MainTex_TexelSize ;
float4 _CameraDepthTexture_TexelSize ;
float4 _VelTex_TexelSize ;
float4x4 _InvViewProj ;
float4x4 _PrevViewProj ;
float4x4 _ToPrevViewProjCombined ;
float _MaxVelocity ;
float _MinVelocity ;
float4 _VelBufferSize ;
float4 _TileBufferSize ;
float4 _BlurDirectionPacked ;
float _SoftZDistance ;

float2 vmax ( float2 a , float2 b )
{
    float ma = dot ( a , a ) ;
    float mb = dot ( b , b ) ;
    return ( ma > mb ) ? a : b ;
}
float cone ( float2 x , float2 y , float2 v )
{
    return clamp ( 1.0 - ( length ( x - y ) / length ( v ) ) , 0.0 , 1.0 ) ;
}
float cylinder ( float2 x , float2 y , float2 v )
{
    float lv = length ( v ) ;
    return 1.0 - smoothstep ( 0.95 * lv , 1.05 * lv , length ( x - y ) ) ;
}
float softDepthCompare ( float za , float zb )
{
    return clamp ( 1.0 - ( za - zb ) / _SoftZDistance , 0.0 , 1.0 ) ;
}

float4 main ( v2f i ) : COLOR
{
    float2 x = i . uv ;
    float2 xf = x ;
    float2 x2 = xf * _VelBufferSize . xy / ( _TileBufferSize . xy * ( float ) ( 8 ) ) ;
    float2 vn = tex2D ( _NeighbourMaxTex , x2 ) . xy ;
    float4 cx = tex2D ( _MainTex , x ) ;
    float zx = tex2D ( _CameraDepthTexture , x ) . x ;
    zx = - Linear01Depth ( zx ) ;
    float2 vx = tex2D ( _VelTex , xf ) . xy ;
    int2 pixelCoord = i . uv * _MainTex_TexelSize . zw ;
    float j = tex2D ( _NoiseTex , i . uv * 4.0f ) . r * ( 0.25f ) ;
    float weight = 1.0 ;
    float4 sum = cx * weight ;
    int centerSample = ( int ) ( ( 13 ) - 1 ) / 2 ;
    for ( int i = 0 ; i < ( 13 ) ; i ++ )
    {
        float contrib = 1.0f ;
        if ( i == centerSample ) contrib = 0.0f ;
        float t = lerp ( - 1.0 , 1.0 , ( i + j + 1.0 ) / ( ( 13 ) + 1.0 ) ) ;
        float2 y = x + vn * t ;
        float2 yf = y ;
        float2 vy = tex2D ( _VelTex , float4 ( yf , 0 , 0 ) . xy ) . xy ;
        float zy = tex2D ( _CameraDepthTexture , float4 ( y , 0 , 0 ) . xy ) . x ;
        zy = - Linear01Depth ( zy ) ;
        float f = softDepthCompare ( zx , zy ) ;
        float b = softDepthCompare ( zy , zx ) ;
        float alphay = f * cone ( y , x , vy ) + b * cone ( x , y , vx ) + cylinder ( y , x , vy ) * cylinder ( x , y , vx ) * 2.0 ;
        float4 cy = tex2D ( _MainTex , float4 ( y , 0 , 0 ) . xy ) ;
        sum += cy * alphay * contrib ;
        weight += alphay * contrib ;
    }
    sum /= weight ;
    return sum ;
}