1. /*
    2.  * Hagelslag.osl by Michel J. Anders (c)2012
    3.  * from https://github.com/sambler/osl-shaders
    4.  *
    5.  * license: cc-by-sa
    6.  *
    7.  * original script from -
    8.  * http://blenderthings.blogspot.com.au/2012/12/a-hagelslag-sprinkles-osl-shader-for.html
    9.  *
    10.  *
    11.  * In blender's homeland hagelslag is the name used for sprinkles.
    12.  * Enjoy sprinkling blender's hagelslag on all your materials
    13.  * to make them as delicious as can be ;)
    14.  * Modified 1/4/2020 by Saul Espinosa for Redshift 3D
    15.  */
    18. // replacement for the missing distance(a, b, q) function
    19. float minimum_distance(point v, point w, point p) {
    20.   vector s = w - v;
    21.   float l2 = dot(s,s);
    22.   if (l2 == 0.0) return distance(p, v);
    23.   float t = dot(p - v, s) / l2;
    24.   if (t < 0.0) return distance(p, v);
    25.   else if (t > 1.0) return distance(p, w);
    26.   vector projection = v + t * (s);
    27.   return distance(p, projection);
    28. }
    30. shader MAHagelslag
    31. [[  string help = "Hagelslag Noise Pattern",
    32.     string label = "Hagelslag Noise" ]]
    33. (
    34.         vector Vector = P,
    35.         float Scale = 1.0
    36.         [[
    37.         float min = 0, float max = 25
    38.         ]],
    39.         int Density = 1
    40.         [[
    41.         float min = 0, float max = 25
    42.         ]],
    43.         int Seed = 0
    44.         [[
    45.         int min = 0, int max = 100
    46.         ]],
    47.         float Radius = 0.05
    48.         [[
    49.         float min = 0, float max = 1
    50.         ]],
    51.         float Size = 1.0
    52.         [[
    53.         float min = 0, float max = 25
    54.         ]],
    56.         output float Fac = 0 )
    57. {
    58.     point p = Vector * Scale;
    59.     point f = floor(p);
    61.     int xx,yy,np;
    62.     vector one = 1;
    64.     for( xx=-1; xx<=1; xx++){
    65.         for( yy=-1; yy<=1; yy++){
    66.             point ff = f + vector(xx,yy,0);
    68.             vector dp = vector(5,7,11);
    70.             for( np=0; np < Density; np++){
    71.                 vector pd1 = 2*cellnoise(ff+dp)-one;
    72.                 vector pd2 = 2*cellnoise(ff+dp+Seed)-one;
    74.                 dp *= 17;
    76.                 point p1 = ff + pd1;
    77.                 point p2 = ff + pd2;
    79.                 p2 = (p2 - p1)*Size+p1;
    81.                 // reduce to 2D
    82.                 p1[2]=0;
    83.                 p2[2]=0;
    84.                 p [2]=0;
    86.                 float r = minimum_distance(p1,p2,p);
    87.                 if ( r < Radius ) {
    88.                     Fac = 1 - r/Radius;
    89.                 }
    90.             }
    91.         }
    92.     }
    93. }